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HTML5 - QUICK GUIDE
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HTML5 - OVERVIEW
HTML5 is the next major revision of the HTML standard superseding HTML 4.01, XHTML 1.0, and
XHTML 1.1. HTML5 is a standard for structuring and presenting content on the World Wide Web.
HTML5 is a cooperation between the World Wide Web Consortium W3C and the Web Hypertext
Application Technology Working Group WHATWG.
The new standard incorporates features like video playback and drag-and-drop that have been
previously dependent on third-party browser plug-ins such as Adobe Flash, Microsoft Silverlight,
and Google Gears.

Browser Support
The latest versions of Apple Safari, Google Chrome, Mozilla Firefox, and Opera all support many
HTML5 features and Internet Explorer 9.0 will also have support for some HTML5 functionality.
The mobile web browsers that come pre-installed on iPhones, iPads, and Android phones all have
excellent support for HTML5.

New Features
HTML5 introduces a number of new elements and attributes that helps in building a modern
website. Following are great features introduced in HTML5.
New Semantic Elements − These are like , , and .
Forms 2.0 − Improvements to HTML web forms where new attributes have been introduced
for  tag.
Persistent Local Storage − To achieve without resorting to third-party plugins.
WebSocket − A a next-generation bidirectional communication technology for web
applications.
Server-Sent Events − HTML5 introduces events which flow from web server to the web
browsers and they are called Server-Sent Events SSE.
Canvas − This supports a two-dimensional drawing surface that you can program with
JavaScript.
Audio & Video − You can embed audio or video on your web pages without resorting to
third-party plugins.
Geolocation − Now visitors can choose to share their physical location with your web
application.
Microdata − This lets you create your own vocabularies beyond HTML5 and extend your
web pages with custom semantics.
Drag and drop − Drag and drop the items from one location to another location on a the
same webpage.

Backward Compatibility
HTML5 is designed, as much as possible, to be backward compatible with existing web browsers.
New features build on existing features and allow you to provide fallback content for older
browsers.
It is suggested to detect support for individual HTML5 features using a few lines of JavaScript.

If you are not familiar with any previous version of HTML, I would recommend to go through our
HTML Tutorial before you explore further concepts of HTM5.

HTML5 - SYNTAX
The HTML 5 language has a "custom" HTML syntax that is compatible with HTML 4 and XHTML1
documents published on the Web, but is not compatible with the more esoteric SGML features of
HTML 4.
HTML 5 does not have the same syntax rules as XHTML where we needed lower case tag names,
quoting our attributes,an attribute had to have a value and to close all empty elements.
But HTML5 is coming with lots of flexibility and would support the followings −
Uppercase tag names.
Quotes are optional for attributes.
Attribute values are optional.
Closing empty elements are optional.

The DOCTYPE
DOCTYPEs in older versions of HTML were longer because the HTML language was SGML based
and therefore required a reference to a DTD.
HTML 5 authors would use simple syntax to specify DOCTYPE as follows −


All the above syntax is case-insensitive.

Character Encoding
HTML 5 authors can use simple syntax to specify Character Encoding as follows −


All the above syntax is case-insensitive.

The 

HTML 5 removes extra information required and you can use simply following syntax −


The  tag
So far you were writing  as follows −


HTML 5 removes extra information required and you can use simply following syntax −


HTML5 Elements

HTML5 elements are marked up using start tags and end tags. Tags are delimited using angle
brackets with the tag name in between.
The difference between start tags and end tags is that the latter includes a slash before the tag
name.
Following is the example of an HTML5 element −
...

HTML5 tag names are case insensitive and may be written in all uppercase or mixed case,
although the most common convention is to stick with lower case.
Most of the elements contain some content like ... contains a paragraph. Some elements,
however, are forbidden from containing any content at all and these are known as void elements.
For example, br, hr, link and meta etc.
Here is a complete list of HTML5 Elements.

HTML5 Attributes
Elements may contain attributes that are used to set various properties of an element.
Some attributes are defined globally and can be used on any element, while others are defined for
specific elements only. All attributes have a name and a value and look like as shown below in the
example.
Following is the example of an HTML5 attributes which illustrates how to mark up a div element
with an attribute named class using a value of "example" −
...

Attributes may only be specified within start tags and must never be used in end tags.
HTML5 attributes are case insensitive and may be written in all upper case or mixed case,
although the most common convention is to stick with lower case.
Here is a complete list of HTML5 Attributes.

HTML5 Document
The following tags have been introduced for better structure −
section − This tag represents a generic document or application section. It can be used
together with h1-h6 to indicate the document structure.
article − This tag represents an independent piece of content of a document, such as a blog
entry or newspaper article.
aside − This tag represents a piece of content that is only slightly related to the rest of the
page.
header − This tag represents the header of a section.
footer − This tag represents a footer for a section and can contain information about the
author, copyright information, etc.
nav − This tag represents a section of the document intended for navigation.
dialog − This tag can be used to mark up a conversation.
figure − This tag can be used to associate a caption together with some embedded content,
such as a graphic or video.
The markup for an HTM 5 document would look like the following −





...


...
...


...


...
...
...






...



HTML5 Document Structure Example
This page should be tried in safari, chrome or Mozila.



HTML Tutorial
CSS Tutorial
JavaScript
Tutorial




Once article can have multiple sections



This is


aside part of the web page





Created by Tutorials Point





This will produce following result −

HTML5 - ATTRIBUTES
As explained in previous chapter, elements may contain attributes that are used to set various
properties of an element.
Some attributes are defined globally and can be used on any element, while others are defined for
specific elements only. All attributes have a name and a value and look like as shown below in the
example.
Following is the example of an HTML5 attributes which illustrates how to mark up a div element
with an attribute named class using a value of "example" −
...

Attributes may only be specified within start tags and must never be used in end tags.
HTML5 attributes are case insensitive and may be written in all uppercase or mixed case, although
the most common convention is to stick with lowercase.

Standard Attributes
The attributes listed below are supported by almost all the HTML 5 tags.
Attribute

Options

Function

accesskey

User Defined

Specifies a keyboard shortcut to access an element.

align

right, left, center

Horizontally aligns tags

background

URL

Places an background image behind an element

bgcolor

numeric,
hexidecimal, RGB
values

Places a background color behind an element

class

User Defined

Classifies an element for use with Cascading Style
Sheets.

contenteditable

true, false

Specifies if the user can edit the element's content or
not.

contextmenu

Menu id

Specifies the context menu for an element.

data-XXXX

User Defined

Custom attributes. Authors of a HTML document can
define their own attributes. Must start with "data-".

draggable

true,false, auto

Specifies whether or not a user is allowed to drag an
element.

height

Numeric Value

Specifies the height of tables, images, or table cells.

hidden

hidden

Specifies whether element should be visible or not.

id

User Defined

Names an element for use with Cascading Style Sheets.

item

List of elements

Used to group elements.

itemprop

List of items

Used to group items.

spellcheck

true, false

Specifies if the element must have it's spelling or
grammar checked.

style

CSS Style sheet

Specifies an inline style for an element.

subject

User define id

Specifies the element's corresponding item.

tabindex

Tab number

Specifies the tab order of an element.

title

User Defined

"Pop-up" title for your elements.

valign

top, middle,
bottom

Vertically aligns tags within an HTML element.

width

Numeric Value

Specifies the width of tables, images, or table cells.

For a complete list of HTML5 Tags and related attributes please check reference to HTML5 Tags.

Custom Attributes
A new feature being introduced in HTML 5 is the addition of custom data attributes.
A custom data attribute starts with data- and would be named based on your requirement.
Following is the simple example −

...


The above will be perfectly valid HTML5 with two custom attributes called data-subject and datalevel. You would be able to get the values of these attributes using JavaScript APIs or CSS in similar
way as you get for standard attributes.

HTML5 - EVENTS
When a user visit your website, they do things like click on text and images and given links, hover
over things etc. These are examples of what JavaScript calls events.
We can write our event handlers in Javascript or vbscript and you can specify these event handlers
as a value of event tag attribute. The HTML5 specification defines various event attributes as listed
below −
There are following attributes which can be used to trigger any javascript or vbscript code given
as value, when there is any event occurs for any HTM5 element.
We would cover element specific events while discussing those elements in detail in subsequent
chapters.
Attribute

Value

Description

offline

script

Triggers when the document goes offline

onabort

script

Triggers on an abort event

onafterprint

script

Triggers after the document is printed

onbeforeonload

script

Triggers before the document loads

onbeforeprint

script

Triggers before the document is printed

onblur

script

Triggers when the window loses focus

oncanplay

script

Triggers when media can start play, but might has to stop for
buffering

oncanplaythrough

script

Triggers when media can be played to the end, without stopping
for buffering

onchange

script

Triggers when an element changes

onclick

script

Triggers on a mouse click

oncontextmenu

script

Triggers when a context menu is triggered

ondblclick

script

Triggers on a mouse double-click

ondrag

script

Triggers when an element is dragged

ondragend

script

Triggers at the end of a drag operation

ondragenter

script

Triggers when an element has been dragged to a valid drop
target

ondragleave

script

Triggers when an element leaves a valid drop target

ondragover

script

Triggers when an element is being dragged over a valid drop
target

ondragstart

script

Triggers at the start of a drag operation

ondrop

script

Triggers when dragged element is being dropped

ondurationchange

script

Triggers when the length of the media is changed

onemptied

script

Triggers when a media resource element suddenly becomes
empty.

onended

script

Triggers when media has reach the end

onerror

script

Triggers when an error occur

onfocus

script

Triggers when the window gets focus

onformchange

script

Triggers when a form changes

onforminput

script

Triggers when a form gets user input

onhaschange

script

Triggers when the document has change

oninput

script

Triggers when an element gets user input

oninvalid

script

Triggers when an element is invalid

onkeydown

script

Triggers when a key is pressed

onkeypress

script

Triggers when a key is pressed and released

onkeyup

script

Triggers when a key is released

onload

script

Triggers when the document loads

onloadeddata

script

Triggers when media data is loaded

onloadedmetadata

script

Triggers when the duration and other media data of a media
element is loaded

onloadstart

script

Triggers when the browser starts to load the media data

onmessage

script

Triggers when the message is triggered

onmousedown

script

Triggers when a mouse button is pressed

onmousemove

script

Triggers when the mouse pointer moves

onmouseout

script

Triggers when the mouse pointer moves out of an element

onmouseover

script

Triggers when the mouse pointer moves over an element

onmouseup

script

Triggers when a mouse button is released

onmousewheel

script

Triggers when the mouse wheel is being rotated

onoffline

script

Triggers when the document goes offline

onoine

script

Triggers when the document comes online

ononline

script

Triggers when the document comes online

onpagehide

script

Triggers when the window is hidden

onpageshow

script

Triggers when the window becomes visible

onpause

script

Triggers when media data is paused

onplay

script

Triggers when media data is going to start playing

onplaying

script

Triggers when media data has start playing

onpopstate

script

Triggers when the window's history changes

onprogress

script

Triggers when the browser is fetching the media data

onratechange

script

Triggers when the media data's playing rate has changed

onreadystatechange

script

Triggers when the ready-state changes

onredo

script

Triggers when the document performs a redo

onresize

script

Triggers when the window is resized

onscroll

script

Triggers when an element's scrollbar is being scrolled

onseeked

script

Triggers when a media element's seeking attribute is no longer
true, and the seeking has ended

onseeking

script

Triggers when a media element's seeking attribute is true, and
the seeking has begun

onselect

script

Triggers when an element is selected

onstalled

script

Triggers when there is an error in fetching media data

onstorage

script

Triggers when a document loads

onsubmit

script

Triggers when a form is submitted

onsuspend

script

Triggers when the browser has been fetching media data, but
stopped before the entire media file was fetched

ontimeupdate

script

Triggers when media changes its playing position

onundo

script

Triggers when a document performs an undo

onunload

script

Triggers when the user leaves the document

onvolumechange

script

Triggers when media changes the volume, also when volume is
set to "mute"

onwaiting

script

Triggers when media has stopped playing, but is expected to
resume

HTML5 - WEB FORMS 2.0
Web Forms 2.0 is an extension to the forms features found in HTML4. Form elements and
attributes in HTML5 provide a greater degree of semantic mark-up than HTML4 and remove a
great deal of the need for tedious scripting and styling that was required in HTML4.

The  element in HTML4
HTML4 input elements use the type attribute to specify the data type.HTML4 provides following
types −
Type

Description

text

A free-form text field, nominally free of line breaks.

password

A free-form text field for sensitive information, nominally free of line breaks.

checkbox

A set of zero or more values from a predefined list.

radio

An enumerated value.

submit

A free form of button initiates form submission.

file

An arbitrary file with a MIME type and optionally a file name.

image

A coordinate, relative to a particular image's size, with the extra semantic that it
must be the last value selected and initiates form submission.

hidden

An arbitrary string that is not normally displayed to the user.

select

An enumerated value, much like the radio type.

textarea

A free-form text field, nominally with no line break restrictions.

button

A free form of button which can initiates any event related to button.

Following is the simple example of using labels, radio buttons, and submit buttons −
...


first name: 


last name: 


email: 


 Male

 Female

 



...

The  element in HTML5
Apart from the above mentioned attributes, HTML5 input elements introduced several new values
for the type attribute. These are listed below.
NOTE − Try all the following example using latest version of Opera browser.
Type

Description

datetime

A date and time year, month, day, hour, minute, second, fractionsofasecond encoded according
to ISO 8601 with the time zone set to UTC.

datetimelocal

A date and time year, month, day, hour, minute, second, fractionsofasecond encoded according
to ISO 8601, with no time zone information.

date

A date year, month, day encoded according to ISO 8601.

month

A date consisting of a year and a month encoded according to ISO 8601.

week

A date consisting of a year and a week number encoded according to ISO 8601.

time

A time hour, minute, seconds, fractionalseconds encoded according to ISO 8601.

number

This accepts only numerical value. The step attribute specifies the precision,
defaulting to 1.

range

The range type is used for input fields that should contain a value from a range of
numbers.

email

This accepts only email value. This type is used for input fields that should contain
an e-mail address. If you try to submit a simple text, it forces to enter only email
address in email@example.com format.

url

This accepts only URL value. This type is used for input fields that should contain a
URL address. If you try to submit a simple text, it forces to enter only URL address
either in http://www.example.com format or in http://example.com format.

The  element
HTML5 introduced a new element  which is used to represent the result of different types
of output, such as output written by a script.
You can use the for attribute to specify a relationship between the output element and other
elements in the document that affected the calculation forexample, asinputsorparameters. The value of
the for attribute is a space-separated list of IDs of other elements.






Enter a value : 






This will produce following result −

The placeholder attribute
HTML5 introduced a new attribute called placeholder. This attribute on  and elements provides a hint to the user of what can be entered in the field. The place holder text must
not contain carriage returns or line-feeds.
Here is the simple syntax for placeholder attribute −
<input type="text" name="search" placeholder="search the web"/>

This attribute is supported by latest versions of Mozilla, Safari and Chrome browsers only.
<!DOCTYPE HTML>
<html>
<body>
<form action="/cgi-bin/html5.cgi" method="get">
Enter email : <input type="email" name="newinput"
placeholder="email@example.com"/>
<input type="submit" value="submit" />
</form>
</body>
</html>

This will produce following result −

The autofocus attribute
This is a simple one-step pattern, easily programmed in JavaScript at the time of document load,
automatically focus one particular form field.

HTML5 introduced a new attribute called autofocus which would be used as follows −
<input type="text" name="search" autofocus/>

This attribute is supported by latest versions of Mozilla, Safari and Chrome browsers only.
<!DOCTYPE HTML>
<html>
<body>
<form action="/cgi-bin/html5.cgi" method="get">
Enter email : <input type="text" name="newinput" autofocus/>
<p>Try to submit using Submit button</p>
<input type="submit" value="submit" />
</form>
</body>
</html>

This will produce following result −

The required attribute
Now you do not need to have javascript for client side validations like empty text box would never
be submitted because HTML5 introduced a new attribute called required which would be used as
follows and would insist to have a value −
<input type="text" name="search" required/>

This attribute is supported by latest versions of Mozilla, Safari and Chrome browsers only.
<!DOCTYPE HTML>
<html>
<body>
<form action="/cgi-bin/html5.cgi" method="get">
Enter email : <input type="text" name="newinput" required/>
<p>Try to submit using Submit button</p>
<input type="submit" value="submit" />
</form>
</body>
>/html>

This will produce following result −

HTML5 - SVG
SVG stands for Scalable Vector Graphics and it is a language for describing 2D-graphics and
graphical applications in XML and the XML is then rendered by an SVG viewer.
SVG is mostly useful for vector type diagrams like Pie charts, Two-dimensional graphs in an X,Y
coordinate system etc.
SVG became a W3C Recommendation 14. January 2003 and you can check latest version of SVG
specification at SVG Specification.

Viewing SVG Files
Most of the web browsers can display SVG just like they can display PNG, GIF, and JPG. Internet
Explorer users may have to install the Adobe SVG Viewer to be able to view SVG in the browser.

Embeding SVG in HTML5
HTML5 allows embeding SVG directly using <svg>...</svg> tag which has following simple
syntax −
<svg xmlns="http://www.w3.org/2000/svg">
...
</svg>

Firefox 3.7 has also introduced a configuration option "about:config" where you can enable HTML5
using the following steps −
Type about:config in your Firefox address bar.
Click the "I'll be careful, I promise!" button on the warning message that appears and make
sure you adhere to it!.
Type html5.enable into the filter bar at the top of the page.
Currently it would be disabled, so click it to toggle the value to true.
Now your Firefox HTML5 parser should now be enabled and you should be able to experiment with
the following examples.

HTML5 − SVG Circle
Following is the HTML5 version of an SVG example which would draw a circle using <circle> tag −
<!DOCTYPE html>
<html>
<head>
<style>
#svgMain {
position: relative;
left: 50%;
-webkit-transform: translateX(-20%);
-ms-transform: translateX(-20%);
transform: translateX(-20%);

}
</style>
<title>SVG</title>
<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Circle</h2>
<svg >
<circle
</svg>

/>

</body>
</html>

This would produce following result in HTML5 enabled latest version of Firefox.
It will produce the following result −

HTML5 − SVG Rectangle
Following is the HTML5 version of an SVG example which would draw a rectangle using <rect> tag
−
<!DOCTYPE html>
<html>
<head>
<style>
#svgelem{
position: relative;
left: 50%;
-webkit-transform: translateX(-50%);
-ms-transform: translateX(-50%);
transform: translateX(-50%);
}
</style>
<title>SVG</title>
<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Rectangle</h2>
<svg >
<rect
</svg>
</body>
</html>

/>

This would produce following result in HTML5 enabled latest version of Firefox.

HTML5 − SVG Line
Following is the HTML5 version of an SVG example which would draw a line using <line> tag −
<!DOCTYPE html>
<html>
<head>
<style>
#svgelem{
position: relative;
left: 50%;
-webkit-transform: translateX(-50%);
-ms-transform: translateX(-50%);
transform: translateX(-50%);
}
</style>
<title>SVG</title>
<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Line</h2>
<svg >
<line x1="0" y1="0" x2="200" y2="100" style="stroke:red;stroke-width:2"/>
</svg>
</body>
</html>

You can use style attribute which allows you to set additional style information like stroke and fill
colors, width of the stroke etc.
This would produce following result in HTML5 enabled latest version of Firefox.

HTML5 − SVG Ellipse

Following is the HTML5 version of an SVG example which would draw an ellipse using <ellipse>
tag −
<!DOCTYPE html>
<html>
<head>
<style>
#svgelem{
position: relative;
left: 50%;
-webkit-transform: translateX(-40%);
-ms-transform: translateX(-40%);
transform: translateX(-40%);
}
</style>
<title>SVG</title>
<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Ellipse</h2>
<svg >
<ellipse cx="100" cy="50" rx="100" ry="50" fill="red" />
</svg>
</body>
</html>

This would produce following result in HTML5 enabled latest version of Firefox.

HTML5 − SVG Polygon
Following is the HTML5 version of an SVG example which would draw a polygon using <polygon>
tag −
<!DOCTYPE html>
<html>
<head>
<style>
#svgelem{
position: relative;
left: 50%;
-webkit-transform: translateX(-50%);
-ms-transform: translateX(-50%);
transform: translateX(-50%);
}
</style>
<title>SVG</title>

<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Polygon</h2>
<svg >
<polygon
</svg>

points="20,10 300,20, 170,50" fill="red" />

</body>
</html>

This would produce following result in HTML5 enabled latest version of Firefox.

HTML5 − SVG Polyline
Following is the HTML5 version of an SVG example which would draw a polyline using <polyline>
tag −
<!DOCTYPE html>
<html>
<head>
<style>
#svgelem{
position: relative;
left: 50%;
-webkit-transform: translateX(-20%);
-ms-transform: translateX(-20%);
transform: translateX(-20%);
}
</style>
<title>SVG</title>
<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Polyline</h2>
<svg >
<polyline points="0,0 0,20 20,20 20,40 40,40 40,60" fill="red" />
</svg>
</body>
</html>

This would produce following result in HTML5 enabled latest version of Firefox.

HTML5 − SVG Gradients
Following is the HTML5 version of an SVG example which would draw a ellipse using <ellipse> tag
and would use <radialGradient> tag to define an SVG radial gradient.
Similar way you can use <linearGradient> tag to create SVG linear gradient.
<!DOCTYPE html>
<html>
<head>
<style>
#svgelem{
position: relative;
left: 50%;
-webkit-transform: translateX(-40%);
-ms-transform: translateX(-40%);
transform: translateX(-40%);
}
</style>
<title>SVG</title>
<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Gradient Ellipse</h2>
<svg >
<defs>
<radialGradient >
<stop offset="0%" style="stop-color:rgb(200,200,200); stop-opacity:0"/>
<stop offset="100%" style="stop-color:rgb(0,0,255); stop-opacity:1"/>
</radialGradient>
</defs>
<ellipse cx="100" cy="50" rx="100" ry="50" style="fill:url(#gradient)" />
</svg>
</body>
</html>

This would produce following result in HTML5 enabled latest version of Firefox.

HTML5 − SVG Star
Following is the HTML5 version of an SVG example which would draw a star using <polygon> tag.
<html>
<head>
<style>
#svgelem{
position: relative;
left: 50%;
-webkit-transform: translateX(-40%);
-ms-transform: translateX(-40%);
transform: translateX(-40%);
}
</style>
<title>SVG</title>
<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Star</h2>
<svg >
<polygon points="100,10 40,180 190,60 10,60 160,180" fill="red"/>
</svg>
</body>
</html>

This would produce following result in HTML5 enabled latest version of Firefox.

HTML5 - MATHML
The HTML syntax of HTML5 allows for MathML elements to be used inside a document using
<math>...</math> tags.
Most of the web browsers can display MathML tags. If your browser does not support MathML, then I
would suggest you to use latest version of Firefox.

MathML Examples
Following is a valid HTML5 document with MathML −

<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>Pythagorean theorem</title>
</head>
<body>
<math xmlns="http://www.w3.org/1998/Math/MathML">
<mrow>
<msup><mi>a</mi><mn>2</mn></msup>
<mo>+</mo>
<msup><mi>b</mi><mn>2</mn></msup>
<mo>=</mo>
<msup><mi>c</mi><mn>2</mn></msup>
</mrow>
</math>
</body>
</html>

This will produce following result −

Using MathML Characters
Consider, following is the markup which makes use of the characters ⁢ −
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>MathML Examples</title>
</head>
<body>
<math xmlns="http://www.w3.org/1998/Math/MathML">
<mrow>
<mrow>
<msup>
<mi>x</mi>
<mn>2</mn>
</msup>
<mo>+</mo>
<mrow>

<mn>4</mn>
<mo>⁢</mo>
<mi>x</mi>
</mrow>
<mo>+</mo>
<mn>4</mn>
</mrow>
<mo>=</mo>
<mn>0</mn>
</mrow>
</math>
</body>
</html>

This would produce following result. If you are not able to see proper result like x2 + 4x + 4 = 0,
then use Firefox 3.5 or higher version.
This will produce following result −

Matrix Presentation Examples
Consider the following example which would be used to represent a simple 2x2 matrix −
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>MathML Examples</title>
</head>
<body>
<math xmlns="http://www.w3.org/1998/Math/MathML">
<mrow>
<mi>A</mi>
<mo>=</mo>
<mfenced open="[" close="]">
<mtable>
<mtr>
<mtd><mi>x</mi></mtd>
<mtd><mi>y</mi></mtd>
</mtr>
<mtr>
<mtd><mi>z</mi></mtd>
<mtd><mi>w</mi></mtd>
</mtr>
</mtable>

</mfenced>
</mrow>
</math>
</body>
</html>

This will produce following result −

This would produce following result. If you are not able to see proper result, then use Fire fox 3.5 or
higher version.

HTML5 - WEB STORAGE
HTML5 introduces two mechanisms, similar to HTTP session cookies, for storing structured data on
the client side and to overcome following drawbacks.
Cookies are included with every HTTP request, thereby slowing down your web application by
transmitting the same data.
Cookies are included with every HTTP request, thereby sending data unencrypted over the
internet.
Cookies are limited to about 4 KB of data . Not enough to store required data.
The two storage's are session storage and local storage and they would be used to handle
different situations.
The latest versions of pretty much every browser supports HTML5 Storage including Internet
Explorer.

Session Storage
The Session Storage is designed for scenarios where the user is carrying out a single transaction,
but could be carrying out multiple transactions in different windows at the same time.

Example
For example, if a user buying plane tickets in two different windows, using the same site. If the site
used cookies to keep track of which ticket the user was buying, then as the user clicked from page
to page in both windows, the ticket currently being purchased would "leak" from one window to the
other, potentially causing the user to buy two tickets for the same flight without really noticing.
HTML5 introduces the sessionStorage attribute which would be used by the sites to add data to the
session storage, and it will be accessible to any page from the same site opened in that window i.e
session and as soon as you close the window, session would be lost.
Following is the code which would set a session variable and access that variable −
<!DOCTYPE HTML>

<html>
<body>
<script type="text/javascript">
if( sessionStorage.hits ){
sessionStorage.hits = Number(sessionStorage.hits) +1;
}
else{
sessionStorage.hits = 1;
}
document.write("Total Hits :" + sessionStorage.hits );
</script>
<p>Refresh the page to increase number of hits.</p>
<p>Close the window and open it again and check the result.</p>
</body>
</html>

This will produce following result −

Local Storage
The Local Storage is designed for storage that spans multiple windows, and lasts beyond the
current session. In particular, Web applications may wish to store megabytes of user data, such as
entire user-authored documents or a user's mailbox, on the client side for performance reasons.
Again, cookies do not handle this case well, because they are transmitted with every request.

Example
HTML5 introduces the localStorage attribute which would be used to access a page's local storage
area without no time limit and this local storage will be available whenever you would use that
page.
Following is the code which would set a local storage variable and access that variable every time
this page is accessed, even next time when you open the window −
<!DOCTYPE HTML>
<html>
<body>
<script type="text/javascript">
if( localStorage.hits ){
localStorage.hits = Number(localStorage.hits) +1;
}
else{
localStorage.hits = 1;
}
document.write("Total Hits :" + localStorage.hits );
</script>

<p>Refresh the page to increase number of hits.</p>
<p>Close the window and open it again and check the result.</p>
</body>
</html>

This will produce following result −

Delete Web Storage
Storing sensitive data on local machine could be dangerous and could leave a security hole.
The Session Storage Data would be deleted by the browsers immediately after the session gets
terminated.
To clear a local storage setting you would need to call localStorage.remove'key'; where 'key' is
the key of the value you want to remove. If you want to clear all settings, you need to call
localStorage.clear method.
Following is the code which would clear complete local storage −
<!DOCTYPE HTML>
<html>
<body>
<script type="text/javascript">
localStorage.clear();
// Reset number of hits.
if( localStorage.hits ){
localStorage.hits = Number(localStorage.hits) +1;
}
else{
localStorage.hits = 1;
}
document.write("Total Hits :" + localStorage.hits );
</script>
<p>Refreshing the page would not to increase hit counter.</p>
<p>Close the window and open it again and check the result.</p>
</body>
</html>

This will produce following result −

HTML5 - WEB SQL DATABASE
The Web SQL Database API isn't actually part of the HTML5 specification but it is a separate
specification which introduces a set of APIs to manipulate client-side databases using SQL.
I'm assuming you are a great web developer and if that is the case then no doubt, you would be
well aware of SQL and RDBMS concepts. If you still want to have a session with SQL then, you can
go through our SQL Tutorial.
Web SQL Database will work in latest version of Safari, Chrome and Opera.

The Core Methods
There are following three core methods defined in the spec that I.m going to cover in this tutorial
−
openDatabase − This method creates the database object either using existing database or
creating new one.
transaction − This method give us the ability to control a transaction and performing either
commit or roll-back based on the situation.
executeSql − This method is used to execute actual SQL query.

Opening Database
The openDatabase method takes care of opening a database if it already exists, this method will
create it if it already does not exist.
To create and open a database, use the following code −
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);

Above method took following five parameters −
Database name
Version number
Text description
Size of database
Creation callback
The last and 5th argument, creation callback will be called if the database is being created.
Without this feature, however, the databases are still being created on the fly and correctly
version.

Executing queries
To execute a query you use the database.transaction function. This function needs a single
argument, which is a function that takes care of actually executing the query as follows −
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);

db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
});

The above query will create a table called LOGS in 'mydb' database.

INSERT Operation
To create eateries into the table we add simple SQL query in the above example as follows −
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (1, "foobar")');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (2, "logmsg")');
});

We can pass dynamic values while creating entering as follows −
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
tx.executeSql('INSERT INTO LOGS (id,log) VALUES (?, ?'), [e_id, e_log];
});

Here e_id and e_log are external variables, and executeSql maps each item in the array argument
to the "?"s.

READ Operation
To read already existing records we use a callback to capture the results as follows −
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (1, "foobar")');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (2, "logmsg")');
});
db.transaction(function (tx) {
tx.executeSql('SELECT * FROM LOGS', [], function (tx, results) {
var len = results.rows.length, i;
msg = "<p>Found rows: " + len + "</p>";
document.querySelector('#status').innerHTML += msg;
for (i = 0; i < len; i++){
alert(results.rows.item(i).log );
}
}, null);
});

Final Example
So finally, let us keep this example in full fledged HTML5 document as follows and try to run it with
Safari browser.
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">

var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
var msg;
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (1, "foobar")');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (2, "logmsg")');
msg = '<p>Log message created and row inserted.</p>';
document.querySelector('#status').innerHTML = msg;
});
db.transaction(function (tx) {
tx.executeSql('SELECT * FROM LOGS', [], function (tx, results) {
var len = results.rows.length, i;
msg = "<p>Found rows: " + len + "</p>";
document.querySelector('#status').innerHTML += msg;
for (i = 0; i < len; i++){
msg = "<p><b>" + results.rows.item(i).log + "</b></p>";
document.querySelector('#status').innerHTML += msg;
}
}, null);
});
</script>
</head>
<body>
<div >Status Message</div>
</body>
</html>

It will produce the following result −

HTML5 - SERVER SENT EVENTS
Conventional web applications generate events which are dispatched to the web server. For
example a simple click on a link requests a new page from the server.
The type of events which are flowing from web browser to the web server may be called client-sent
events.
Along with HTML5, WHATWG Web Applications 1.0 introduces events which flow from web server
to the web browsers and they are called Server-Sent Events SSE. Using SSE you can push DOM
events continously from your web server to the visitor's browser.
The event streaming approach opens a persistent connection to the server, sending data to the
client when new information is available, eliminating the need for continuous polling.
Server-sent events standardizes how we stream data from the server to the client.

Web Application for SSE
To use Server-Sent Events in a web application, you would need to add an <eventsource>
element to the document.

The src attribute of <eventsource> element should point to an URL which should provide a
persistent HTTP connection that sends a data stream containing the events.
The URL would point to a PHP, PERL or any Python script which would take care of sending event
data consistently. Following is a simple example of web application which would expect server
time.
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
/* Define event handling logic here */
</script>
</head>
<body>
<div >
<eventsource src="/cgi-bin/ticker.cgi" />
</div>
<div >
<TIME>
</div>
</body>
</html>

Server Side Script for SSE
A server side script should send Content-type header specifying the type text/event-stream as
follows.
print "Content-Type: text/event-stream\n\n";

After setting Content-Type, server side script would send an Event: tag followed by event name.
Following example would send Server-Time as event name terminated by a new line character.
print "Event: server-time\n";

Final step is to send event data using Data: tag which would be followed by integer of string value
terminated by a new line character as follows −
$time = localtime();
print "Data: $time\n";

Finally, following is complete ticker.cgi written in perl −
#!/usr/bin/perl
print "Content-Type: text/event-stream\n\n";
while(true){
print "Event: server-time\n";
$time = localtime();
print "Data: $time\n";
sleep(5);
}

Handle Server-Sent Events

Let us modify our web application to handle server-sent events. Following is the final example.
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
document.getElementsByTagName("eventsource")[0].addEventListener("server-time",
eventHandler, false);
function eventHandler(event)
{
// Alert time sent by the server
document.querySelector('#ticker').innerHTML = event.data;
}
</script>
</head>
<body>
<div >
<eventsource src="/cgi-bin/ticker.cgi" />
</div>
<div >
[TIME]
</div>
</body>
</html>

Before testing Server-Sent events, I would suggest to make sure if your web browser supports this
concept.

HTML5 - WEBSOCKETS
Web Sockets is a next-generation bidirectional communication technology for web applications
which operates over a single socket and is exposed via a JavaScript interface in HTML 5 compliant
browsers.
Once you get a Web Socket connection with the web server, you can send data from browser to
server by calling a send method, and receive data from server to browser by an onmessage
event handler.
Following is the API which creates a new WebSocket object.
var Socket = new WebSocket(url, [protocal] );

Here first argument, url, specifies the URL to which to connect. The second attribute, protocol is
optional, and if present, specifies a sub-protocol that the server must support for the connection to
be successful.

WebSocket Attributes
Following are the attribute of WebSocket object. Assuming we created Socket object as mentioned
above −
Attribute
Socket.readyState

Description
The readonly attribute readyState represents the state of the
connection. It can have the following values −

A value of 0 indicates that the connection has not yet been
established.
A value of 1 indicates that the connection is established and
communication is possible.
A value of 2 indicates that the connection is going through
the closing handshake.
A value of 3 indicates that the connection has been closed or
could not be opened.
Socket.bufferedAmount

The readonly attribute bufferedAmount represents the number
of bytes of UTF-8 text that have been queued using send method.

WebSocket Events
Following are the events associated with WebSocket object. Assuming we created Socket object as
mentioned above −
Event

Event Handler

Description

open

Socket.onopen

This event occurs when socket connection is established.

message

Socket.onmessage

This event occurs when client receives data from server.

error

Socket.onerror

This event occurs when there is any error in
communication.

close

Socket.onclose

This event occurs when connection is closed.

WebSocket Methods
Following are the methods associated with WebSocket object. Assuming we created Socket object
as mentioned above −
Method
Socket.send

Socket.close

Description
The senddata method transmits data using the connection.

The close method would be used to terminate any existing connection.

WebSocket Example
A WebSocket is a standard bidirectional TCP socket between the client and the server. The socket
starts out as a HTTP connection and then "Upgrades" to a TCP socket after a HTTP handshake.
After the handshake, either side can send data.

Client Side HTML & JavaScript Code
At the time of writing this tutorial, there are only few web browsers supporting WebSocket
interface. You can try following example with latest version of Chrome, Mozilla, Opera and Safari.
<!DOCTYPE HTML>

<html>
<head>
<script type="text/javascript">
function WebSocketTest()
{
if ("WebSocket" in window)
{
alert("WebSocket is supported by your Browser!");
// Let us open a web socket
var ws = new WebSocket("ws://localhost:9998/echo");
ws.onopen = function()
{
// Web Socket is connected, send data using send()
ws.send("Message to send");
alert("Message is sent...");
};
ws.onmessage = function (evt)
{
var received_msg = evt.data;
alert("Message is received...");
};
ws.onclose = function()
{
// websocket is closed.
alert("Connection is closed...");
};
}
else
{
// The browser doesn't support WebSocket
alert("WebSocket NOT supported by your Browser!");
}
}
</script>
</head>
<body>
<div >
<a href="javascript:WebSocketTest()">Run WebSocket</a>
</div>
</body>
</html>

Install pywebsocket
Before you test above client program, you need a server which supports WebSocket. Download
mod_pywebsocket-x.x.x.tar.gz from pywebsocket which aims to provide a Web Socket extension
for Apache HTTP Server ans install it following these steps.
Unzip and untar the downloaded file.
Go inside pywebsocket-x.x.x/src/ directory.
$python setup.py build
$sudo python setup.py install
Then read document by:

$pydoc mod_pywebsocket
This will install it into your python environment.

Start the Server
Go to the pywebsocket-x.x.x/src/mod_pywebsocket folder and run the following command −
$sudo python standalone.py -p 9998 -w ../example/

This will start the server listening at port 9998 and use the handlers directory specified by the -w
option where our echo_wsh.py resides.
Now using Chrome browser open the html file your created in the beginning. If your browser
supports WebSocket, then you would get alert indicating that your browser supports WebSocket
and finally when you click on "Run WebSocket" you would get Goodbye message sent by the
server script.

HTML5 - CANVAS
HTML5 element <canvas> gives you an easy and powerful way to draw graphics using JavaScript.
It can be used to draw graphs, make photo compositions or do simple and not so simple
animations.
Here is a simple <canvas> element which has only two specific attributes width and height plus
all the core HTML5 attributes like id, name and class etc.
<canvas ></canvas>

You can easily find that <canvas> element in the DOM using getElementById method as follows −
var canvas

= document.getElementById("mycanvas");

Let us see a simple example on using <canvas> element in HTML5 document.
<!DOCTYPE HTML>
<html>
<head>
<style>
#mycanvas{border:1px solid red;}
</style>
</head>
<body>
<canvas ></canvas>
</body>
</html>

This will produce following result −

The Rendering Context

The <canvas> is initially blank, and to display something, a script first needs to access the
rendering context and draw on it.
The canvas element has a DOM method called getContext, used to obtain the rendering context
and its drawing functions. This function takes one parameter, the type of context 2d.
Following is the code to get required context along with a check if your browser supports
<canvas> element −
var canvas

= document.getElementById("mycanvas");

if (canvas.getContext){
var ctx = canvas.getContext('2d');
// drawing code here
}
else {
// canvas-unsupported code here
}

Browser Support
The latest versions of Firefox, Safari, Chrome and Opera all support for HTML5 Canvas but IE8 does
not support canvas natively.
You can use ExplorerCanvas to have canvas support through Internet Explorer. You just need to
include this javascript as follows:
<!--[if IE]><script src="excanvas.js"></script><![endif]-->

HTML5 Canvas Examples
This tutorial covers following examples related to HTML5 <canvas> element.
Examples

Description

Drawing Rectangles

Learn how to draw rectangle using HTML5 <canvas> element

Drawing Paths

Learn how to make shapes using paths in HTML5 <canvas>
element

Drawing Lines

Learn how to draw lines using HTML5 <canvas> element

Drawing Bezier

Learn how to draw bezier curve using HTML5 <canvas> element

Drawing Quadratic

Learn how to draw quadratic curve using HTML5 <canvas>
element

Using Images

Learn how to use images with HTML5 <canvas> element

Create Gradients

Learn how to create gradients using HTML5 <canvas> element

Styles and Colors

Learn how to apply styles and colors using HTML5 <canvas>
element

Text and Fonts

Learn how to draw amazing text using different fonts and their
size.

Pattern and Shadow

Learn how to draw different patterns and drop shadows.

Canvas States

Learn how to save and restore canvas states while doing complex
drawings on a canvas.

Canvas Translation

This method is used to move the canvas and its origin to a
different point in the grid.

Canvas Rotation

This method is used to rotate the canvas around the current origin.

Canvas Scaling

This method is used to increase or decrease the units in a canvas
grid.

Canvas Transform

These methods allow modifications directly to the transformation
matrix.

Canvas Composition

This method is used to mask off certain areas or clear sections
from the canvas.

Canvas Animation

Learn how to create basic animation using HTML5 canvas and
Javascript.

HTML5 - AUDIO & VIDEO
HTML5 features, include native audio and video support without the need for Flash.
The HTML5 <audio> and <video> tags make it simple to add media to a website. You need to set
src attribute to identify the media source and include a controls attribute so the user can play and
pause the media.

Embedding Video
Here is the simplest form of embedding a video file in your webpage −
<video src="foo.mp4" width="300" height="200" controls>
Your browser does not support the <video> element.
</video>

The current HTML5 draft specification does not specify which video formats browsers should
support in the video tag. But most commonly used video formats are −

Ogg − Ogg files with Thedora video codec and Vorbis audio codec.
mpeg4 − MPEG4 files with H.264 video codec and AAC audio codec.
You can use <source> tag to specify media along with media type and many other attributes. A
video element allows multiple source elements and browser will use the first recognized format −
<!DOCTYPE HTML>
<html>
<body>
<video width="300" height="200" controls autoplay>
<source src="/html5/foo.ogg" type="video/ogg" />
<source src="/html5/foo.mp4" type="video/mp4" />
Your browser does not support the <video> element.
</video>
</body>
</html>

This will produce following result −

Video Attribute Specification
The HTML5 video tag can have a number of attributes to control the look and feel and various
functionalities of the control −
Attribute

Description

autoplay

This boolean attribute if specified, the video will automatically begin to play back
as soon as it can do so without stopping to finish loading the data.

autobuffer

This boolean attribute if specified, the video will automatically begin buffering even
if it's not set to automatically play.

controls

If this attribute is present, it will allow the user to control video playback, including
volume, seeking, and pause/resume playback.

height

This attribute specifies the height of the video's display area, in CSS pixels.

loop

This boolean attribute if specified, will allow video automatically seek back to the
start after reaching at the end.

preload

This attribute specifies that the video will be loaded at page load, and ready to run.
Ignored if autoplay is present.

poster

This is a URL of an image to show until the user plays or seeks.

src

The URL of the video to embed. This is optional; you may instead use the <source>
element within the video block to specify the video to embed

width

This attribute specifies the width of the video's display area, in CSS pixels.

Embedding Audio
HTML5 supports <audio> tag which is used to embed sound content in an HTML or XHTML
document as follows.
<audio src="foo.wav" controls autoplay>
Your browser does not support the <audio> element.
</audio>

The current HTML5 draft specification does not specify which audio formats browsers should
support in the audio tag. But most commonly used audio formats are ogg, mp3 and wav.
You can use <source> tag to specify media along with media type and many other attributes. An
audio element allows multiple source elements and browser will use the first recognized format −
<!DOCTYPE HTML>
<html>
<body>
<audio controls autoplay>
<source src="/html5/audio.ogg" type="audio/ogg" />
<source src="/html5/audio.wav" type="audio/wav" />
Your browser does not support the <audio> element.
</audio>
</body>
</html>

This will produce following result −

Audio Attribute Specification
The HTML5 audio tag can have a number of attributes to control the look and feel and various
functionalities of the control:
Attribute

Description

autoplay

This boolean attribute if specified, the audio will automatically begin to play back
as soon as it can do so without stopping to finish loading the data.

autobuffer

This boolean attribute if specified, the audio will automatically begin buffering even
if it's not set to automatically play.

controls

If this attribute is present, it will allow the user to control audio playback, including
volume, seeking, and pause/resume playback.

loop

This boolean attribute if specified, will allow audio automatically seek back to the
start after reaching at the end.

preload

This attribute specifies that the audio will be loaded at page load, and ready to run.
Ignored if autoplay is present.

src

The URL of the audio to embed. This is optional; you may instead use the <source>
element within the video block to specify the video to embed

Handling Media Events
The HTML5 audio and video tag can have a number of attributes to control various functionalities
of the control using Javascript −
Event

Description

abort

This event is generated when playback is aborted.

canplay

This event is generated when enough data is available that the media can be
played.

ended

This event is generated when playback completes.

error

This event is generated when an error occurs.

loadeddata

This event is generated when the first frame of the media has finished loading.

loadstart

This event is generated when loading of the media begins.

pause

This event is generated when playback is paused.

play

This event is generated when playback starts or resumes.

progress

This event is generated periodically to inform the progress of the downloading
the media.

ratechange

This event is generated when the playback speed changes.

seeked

This event is generated when a seek operation completes.

seeking

This event is generated when a seek operation begins.

suspend

This event is generated when loading of the media is suspended.

volumechange

This event is generated when the audio volume changes.

waiting

This event is generated when the requested operation such as playback is
delayed pending the completion of another operation such as a seek.

Following is the example which allows to play the given video −
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
function PlayVideo(){
var v = document.getElementsByTagName("video")[0];
v.play();
}
</script>
</head>
<body>
<form>
<video width="300" height="200" src="/html5/foo.mp4">
Your browser does not support the video element.
</video>
</br>
<input type="button" onclick="PlayVideo();"
</form>

value="Play"/>

</body>
</html>

This will produce following result −

Configuring Servers for Media Type
Most servers don't by default serve Ogg or mp4 media with the correct MIME types, so you'll likely
need to add the appropriate configuration for this.
AddType
AddType
AddType
AddType

audio/ogg
audio/wav
video/ogg
video/mp4

.oga
.wav
.ogv .ogg
.mp4

HTML5 - GEOLOCATION
HTML5 Geolocation API lets you share your location with your favorite web sites. A Javascript can
capture your latitude and longitude and can be sent to backend web server and do fancy locationaware things like finding local businesses or showing your location on a map.
Today most of the browsers and mobile devices support Geolocation API. The geolocation APIs
work with a new property of the global navigator object ie. Geolocation object which can be
created as follows:
var geolocation = navigator.geolocation;

The geolocation object is a service object that allows widgets to retrieve information about the
geographic location of the device.

Geolocation Methods
The geolocation object provides the following methods −
Method
getCurrentPosition

watchPosition

clearWatch

Example

Description
This method retrieves the current geographic location of the user.

This method retrieves periodic updates about the current geographic
location of the device.

This method cancels an ongoing watchPosition call.

Following is a sample code to use any of the above method −
function getLocation() {
var geolocation = navigator.geolocation;
geolocation.getCurrentPosition(showLocation, errorHandler);
}

Here showLocation and errorHandler are callback methods which would be used to get actual
position as explained in next section and to handle errors if there is any.

Location Properties
Geolocation methods getCurrentPosition and getPositionUsingMethodName specify the callback
method that retrieves the location information. These methods are called asynchronously with an
object Position which stores the complete location information.
The Position object specifies the current geographic location of the device. The location is
expressed as a set of geographic coordinates together with information about heading and speed.
The following table describes the properties of the Position object. For the optional properties if the
system cannot provide a value, the value of the property is set to null.
Property

Type

coords

objects

coords.latitude

Number

coords.longitude

Number

coords.altitude

Number

coords.accuracy

Number

coords.altitudeAccuracy

Number

coords.heading

Number

coords.speed

Number

timestamp

date

Description
Specifies the geographic location of the device. The
location is expressed as a set of geographic coordinates
together with information about heading and speed.

Specifies the latitude estimate in decimal degrees. The
value range is [-90.00, +90.00].

Specifies the longitude estimate in decimal degrees. The
value range is [-180.00, +180.00].

[Optional] Specifies the altitude estimate in meters above
the WGS 84 ellipsoid.

[Optional] Specifies the accuracy of the latitude and
longitude estimates in meters.

[Optional] Specifies the accuracy of the altitude estimate
in meters.

[Optional] Specifies the device's current direction of
movement in degrees counting clockwise relative to true
north.

[Optional] Specifies the device's current ground speed in
meters per second.

timestamp

date

Specifies the time when the location information was
retrieved and the Position object created.

Example
Following is a sample code which makes use of Position object. Here showLocation method is a
callback method −
function showLocation( position ) {
var latitude = position.coords.latitude;
var longitude = position.coords.longitude;
...
}

Handling Errors
Geolocation is complicated, and it is very much required to catch any error and handle it
gracefully.
The geolocations methods getCurrentPosition and watchPosition make use of an error handler
callback method which gives PositionError object. This object has following two properties −
Property

Type

code

Number

message

String

Description
Contains a numeric code for the error.

Contains a human-readable description of the error.

The following table describes the possible error codes returned in the PositionError object.
Code

Constant

0

UNKNOWN_ERROR

1

PERMISSION_DENIED

2

POSITION_UNAVAILABLE

3

TIMEOUT

Description
The method failed to retrieve the location of the device due
to an unknown error.

The method failed to retrieve the location of the device
because the application does not have permission to use the
Location Service.

The location of the device could not be determined.

The method was unable to retrieve the location information
within the specified maximum timeout interval.

Example
Following is a sample code which makes use of PositionError object. Here errorHandler method is
a callback method −

function errorHandler( err ) {
if (err.code == 1) {
// access is denied
}
...
}

Position Options
Following is the actual syntax of getCurrentPosition method −
getCurrentPosition(callback, ErrorCallback, options)

Here third argument is the PositionOptions object which specifies a set of options for retrieving
the geographic location of the device.
Following are the options which can be specified as third argument −
Property

Type

enableHighAccuracy

Boolean

timeout

Number

maximumAge

Number

Description
Specifies whether the widget wants to receive the most
accurate location estimate possible. By default this is false.

The timeout property is the number of milliseconds your web
application is willing to wait for a position.

Specifies the expiry time in milliseconds for cached location
information.

Example
Following is a sample code which shows how to use above mentioned methods −
function getLocation() {
var geolocation = navigator.geolocation;
geolocation.getCurrentPosition(showLocation, errorHandler, {maximumAge: 75000});
}

HTML5 - MICRODATA
Microdata is a standardized way to provide additional semantics in your web pages.
Microdata lets you define your own customized elements and start embedding custom properties
in your web pages. At a high level, microdata consists of a group of name-value pairs.
The groups are called items, and each name-value pair is a property. Items and properties are
represented by regular elements.

Example
To create an item, the itemscope attribute is used.
To add a property to an item, the itemprop attribute is used on one of the item's
descendants.
Here there are two items, each of which has the property "name" −

<html>
<body>
<div itemscope>
<p>My name is <span itemprop="name">Zara</span>.</p>
</div>
<div itemscope>
<p>My name is <span itemprop="name">Nuha</span>.</p>
</div>
</body>
</html>

It will produce the following result −

Properties generally have values that are strings but it can have following data types −

Global Attributes
Micro data introduces five global attributes which would be available for any element to use and
give context for machines about your data.
Attribute

Description

itemscope

This is used to create an item. The itemscope attribute is a boolean attribute that
tells that there is Microdata on this page, and this is where it starts.

itemtype

This attribute is a valid URL which defines the item and provides the context for the
properties.

itemid

This attribute is global identifier for the item.

itemprop

This attribute defines a property of the item.

itemref

This attribute gives a list of additional elements to crawl to find the name-value
pairs of the item.

Properties Datatypes
Properties generally have values that are strings as mentioned in above example but they can also
have values that are URLs. Following example has one property, "image", whose value is a URL −
<div itemscope>
<img itemprop="image" src="tp-logo.gif" alt="TutorialsPoint">
</div>

Properties can also have values that are dates, times, or dates and times. This is achieved using
the time element and its datetime attribute.
<html>
<body>

<div itemscope>
My birthday is:
<time itemprop="birthday" datetime="1971-05-08">
Aug 5th 1971
</time>
</div>
</body>
</html>

It will produce the following result −

Properties can also themselves be groups of name-value pairs, by putting the itemscope attribute
on the element that declares the property.

Microdata API support
If a browser supports the HTML5 microdata API, there will be a getItems function on the global
document object. If browser doesn't support microdata, the getItems function will be undefined.
function supports_microdata_api() {
return !!document.getItems;
}

Modernizr does not yet support checking for the microdata API, so you’ll need to use the function
like the one listed above.
The HTML5 microdata standard includes both HTML markup primarily for search engines and a set
of DOM functions primarily for browsers.
You can include microdata markup in your web pages, and search engines that don't understand
the microdata attributes will just ignore them. But if you need to access or manipulate microdata
through the DOM, you'll need to check whether the browser supports the microdata DOM API.

Defining Microdata Vocabulary
To define microdata vocabulary you need a namespace URL which points to a working web page.
For example http://data-vocabulary.org/Person can be used as the namespace for a personal
microdata vocabulary with the following named properties −
name − Person name as a simple string
Photo − A URL to a picture of the person.
URL − A website belonging to the person.
Using about properties a person microdata could be as follows −
<html>
<body>
<div itemscope>

<section itemscope itemtype="http://data-vocabulary.org/Person">
<h1 itemprop="name">Gopal K Varma</h1>
<p>
<img itemprop="photo"
src="http://www.tutorialspoint.com/green/images/logo.png">
</p>
<a itemprop="url" href="http://www.tutorialspoint.com">Site</a>
</section>
</div>
</body>
</html>

It will produce the following result −

Google supports microdata as part of their Rich Snippets program. When Google's web crawler
parses your page and finds microdata properties that conform to the http://datavocabulary.org/Person vocabulary, it parses out those properties and stores them alongside the
rest of the page data.
You can test above example using Rich Snippets Testing Tool using
http://www.tutorialspoint.com/html5/microdata.htm
For further development on Microdata you can always refer to HTML5 Micordata.

HTML5 - DRAG & DROP
Drag and Drop DnD is powerful User Interface concept which makes it easy to copy, reorder and
deletion of items with the help of mouse clicks. This allows the user to click and hold the mouse
button down over an element, drag it to another location, and release the mouse button to drop
the element there.
To achieve drag and drop functionality with traditional HTML4, developers would either have to
either have to use complex Javascript programming or other Javascript frameworks like jQuery etc.
Now HTML 5 came up with a Drag and Drop DnD API that brings native DnD support to the browser
making it much easier to code up.
HTML 5 DnD is supported by all the major browsers like Chrome, Firefox 3.5 and Safari 4 etc.

Drag and Drop Events
There are number of events which are fired during various stages of the drag and drop operation.
These events are listed below −
Events

Description

dragstart

Fires when the user starts dragging of the object.

dragenter

Fired when the mouse is first moved over the target element while a drag is
occuring. A listener for this event should indicate whether a drop is allowed over
this location. If there are no listeners, or the listeners perform no operations, then a

drop is not allowed by default.
dragover

This event is fired as the mouse is moved over an element when a drag is occuring.
Much of the time, the operation that occurs during a listener will be the same as the
dragenter event.

dragleave

This event is fired when the mouse leaves an element while a drag is occuring.
Listeners should remove any highlighting or insertion markers used for drop
feedback.

drag

Fires every time the mouse is moved while the object is being dragged.

drop

The drop event is fired on the element where the drop was occured at the end of
the drag operation. A listener would be responsible for retrieving the data being
dragged and inserting it at the drop location.

dragend

Fires when the user releases the mouse button while dragging an object.

Note &mius; Note that only drag events are fired; mouse events such as mousemove are not fired
during a drag operation.

The DataTransfer Object
The event listener methods for all the drag and drop events accept Event object which has a
readonly attribute called dataTransfer. The event.dataTransfer returns DataTransfer object
associated with the event as follows −
function EnterHandler(event) {
DataTransfer dt = event.dataTransfer;
.............
}

The DataTransfer object holds data about the drag and drop operation. This data can be retrieved
and set in terms of various attributes associated with DataTransfer object as explained below:
Sr.No.

DataTransfer attributes and their description

1

dataTransfer.dropEffect [ = value ]
Returns the kind of operation that is currently selected.
This attribute can be set, to change the selected operation.
The possible values are none, copy, link, and move.

2

dataTransfer.effectAllowed [ = value ]
Returns the kinds of operations that are to be allowed.
This attribute can be set, to change the allowed operations.
The possible values are none, copy, copyLink, copyMove, link, linkMove,
move, all and uninitialized.

3

dataTransfer.types
Returns a DOMStringList listing the formats that were set in the dragstart event. In
addition, if any files are being dragged, then one of the types will be the string "Files".

4

dataTransfer.clearData [ format ]
Removes the data of the specified formats. Removes all data if the argument is

omitted.
5

dataTransfer.setDataformat, data
Adds the specified data.

6

data = dataTransfer.getDataformat
Returns the specified data. If there is no such data, returns the empty string.

7

dataTransfer.files
Returns a FileList of the files being dragged, if any.

8

dataTransfer.setDragImageelement, x, y
Uses the given element to update the drag feedback, replacing any previously
specified feedback.

9

dataTransfer.addElementelement
Adds the given element to the list of elements used to render the drag feedback.

Drag and Drop Process
Following are the steps to be carried out to implement Drag and Drop operation −

Step 1: Making an Object Draggable
Here are steps to be taken −
If you want to drag an element, you need to set the draggable attribute to true for that
element.
Set an event listener for dragstart that stores the data being dragged.
The event listener dragstart will set the allowed effects copy, move, link, or some
combination.
Following is the example to make an object dragable −
<!DOCTYPE HTML>
<html>
<head>
<style type="text/css">
#boxA, #boxB {
float:left;padding:10px;margin:10px; -moz-user-select:none;
}
#boxA { background-color: #6633FF; width:75px; height:75px; }
#boxB { background-color: #FF6699; width:150px; height:150px; }
</style>
<script type="text/javascript">
function dragStart(ev) {
ev.dataTransfer.effectAllowed='move';
ev.dataTransfer.setData("Text", ev.target.getAttribute('id'));
ev.dataTransfer.setDragImage(ev.target,0,0);
return true;

}
</script>
</head>
<body>
<center>
<h2>Drag and drop HTML5 demo</h2>
<div>Try to drag the purple box around.</div>
<div
ondragstart="return dragStart(event)">
<p>Drag Me</p>
</div>
<div >Dustbin</div>
</center>
</body>
</html>

This will produce following result −

Step 2: Dropping the Object
To accept a drop, the drop target has to listen to at least three events.
The dragenter event, which is used to determine whether or not the drop target is to accept
the drop. If the drop is to be accepted, then this event has to be canceled.
The dragover event, which is used to determine what feedback is to be shown to the user. If
the event is canceled, then the feedback typically the cursor is updated based on the
dropEffect attribute's value.
Finally, the drop event, which allows the actual drop to be performed.
Following is the example to drop an object into another object −
<!DOCTYPE HTML>
<html>
<head>
<style type="text/css">
#boxA, #boxB {
float:left;padding:10px;margin:10px;-moz-user-select:none;
}
#boxA { background-color: #6633FF; width:75px; height:75px; }
#boxB { background-color: #FF6699; width:150px; height:150px; }
</style>
<script type="text/javascript">
function dragStart(ev) {
ev.dataTransfer.effectAllowed='move';
ev.dataTransfer.setData("Text", ev.target.getAttribute('id'));
ev.dataTransfer.setDragImage(ev.target,0,0);

return true;
}
function dragEnter(ev) {
event.preventDefault();
return true;
}
function dragOver(ev) {
return false;
}
function dragDrop(ev) {
var src = ev.dataTransfer.getData("Text");
ev.target.appendChild(document.getElementById(src));
ev.stopPropagation();
return false;
}
</script>
</head>
<body>
<center>
<h2>Drag and drop HTML5 demo</h2>
<div>Try to move the purple box into the pink box.</div>
<div
ondragstart="return dragStart(event)">
<p>Drag Me</p>
</div>
<div
ondrop="return dragDrop(event)"
ondragover="return dragOver(event)">Dustbin
</div>
</center>
</body>
</html>

This will produce following result −

HTML5 - WEB WORKERS
JavaScript was designed to run in a single-threaded environment, meaning multiple scripts cannot
run at the same time. Consider a situation where you need to handle UI events, query and process
large amounts of API data, and manipulate the DOM.
Javascript will hang your browser in situation where CPU utilization is high. Let us take a simple
example where Javascript goes through a big loop −
<!DOCTYPE HTML>
<html>
<head>
<title>Big for loop</title>

<script>
function bigLoop(){
for (var i = 0; i <= 10000; i += 1){
var j = i;
}
alert("Completed " + j + "iterations" );
}
function sayHello(){
alert("Hello sir...." );
}
</script>
</head>
<body>
<input type="button" onclick="bigLoop();" value="Big Loop" />
<input type="button" onclick="sayHello();" value="Say Hello" />
</body>
</html>

It will produce the following result −

When you click Big Loop button it displays following result in Firefox −

What is Web Workers?
The situation explained above can be handled using Web Workers who will do all the
computationally expensive tasks without interrupting the user interface and typically run on
separate threads.
Web Workers allow for long-running scripts that are not interrupted by scripts that respond to
clicks or other user interactions, and allows long tasks to be executed without yielding to keep the
page responsive.
Web Workers are background scripts and they are relatively heavy-weight, and are not intended to
be used in large numbers. For example, it would be inappropriate to launch one worker for each
pixel of a four megapixel image.
When a script is executing inside a Web Worker it cannot access the web page's window object
window.document, which means that Web Workers don't have direct access to the web page and
the DOM API. Although Web Workers cannot block the browser UI, they can still consume CPU

cycles and make the system less responsive.

How Web Workers Work?
Web Workers are initialized with the URL of a JavaScript file, which contains the code the worker
will execute. This code sets event listeners and communicates with the script that spawned it from
the main page. Following is the simple syntax −
var worker = new Worker('bigLoop.js');

If the specified javascript file exists, the browser will spawn a new worker thread, which is
downloaded asynchronously. If the path to your worker returns an 404, the worker will fail silently.
If your application has multiple supporting javascript files, you can import them importScripts
method which takes file names as argument separated by comma as follows −
importScripts("helper.js", "anotherHelper.js");

Once the Web Worker is spawned, communication between web worker and its parent page is
done using the postMessage method. Depending on your browser/version, postMessage can
accept either a string or JSON object as its single argument.
Message passed by Web Worker is accessed using onmessage event in the main page. Now let us
write our bigLoop example using Web Worker. Below is the main page hello.htm which will spawn
a web worker to execute the loop and to return the final value of variable j −
<!DOCTYPE HTML>
<html>
<head>
<title>Big for loop</title>
<script>
var worker = new Worker('bigLoop.js');
worker.onmessage = function (event) {
alert("Completed " + event.data + "iterations" );
};
function sayHello(){
alert("Hello sir...." );
}
</script>
</head>
<body>
<input type="button" onclick="sayHello();" value="Say Hello"/>
</body>
</html>

Following is the content of bigLoop.js file. This makes use of postMessage API to pass the
communication back to main page −
for (var i = 0; i <= 1000000000; i += 1){
var j = i;
}
postMessage(j);

This will produce following result −

Now let us keep hello.htm and bigLoop.js file in the same directory and try to access hello.htm
using latest version of either Safari or Firefox.

Stopping Web Workers
Web Workers don't stop by themselves but the page that started them can stop them by calling
terminate method.
worker.terminate();

A terminated Web Worker will no longer respond to messages or perform any additional
computations. You cannot restart a worker; instead, you can create a new worker using the same
URL.

Handling Errors
The following shows an example of an error handling function in a Web Worker JavaScript file that
logs errors to the console. With error handling code, above example would become as following −
<!DOCTYPE HTML>
<html>
<head>
<title>Big for loop</title>
<script>
var worker = new Worker('bigLoop.js');
worker.onmessage = function (event) {
alert("Completed " + event.data + "iterations" );
};
worker.onerror = function (event) {
console.log(event.message, event);
};
function sayHello(){
alert("Hello sir...." );
}
</script>
</head>
<body>
<input type="button" onclick="sayHello();" value="Say Hello"/>
</body>
</html>

Checking for Browser Support
Following is the syntax to detect a Web Worker feature support available in a browser
<!DOCTYPE HTML>
<html>

<head>
<title>Big for loop</title>
<script src="/js/modernizr-1.5.min.js"></script>
<script>
if (Modernizr.webworkers) {
alert("Congratulation!! you have web workers support." );
}
else{
alert("Sorry!! you do not have web workers support." );
}
</script>
</head>
<body>
<p>Checking for Browser Support for web workers</p>
</body>
</html>

This will produce following result −

HTML5 - INDEXEDDB
The indexeddb is a new HTML5 concept to store the data inside user's browser. indexeddb is more
power than local storage and useful for applications that requires to store large amount of the
data. These applications can run more efficiency and load faster.

Why to use indexeddb?
The W3C has announced that the Web SQL database is a deprecated local storage specification so
web developer should not use this technology any more. indexeddb is an alternative for web SQL
data base and more effective than older technologies.

Features
it stores key-pair values
it is not a relational database
IndexedDB API is mostly asynchronous
it is not a structured query language
it has supported to access the data from same domain

IndexedDB
Before enter into an indexeddb, we need to add some prefixes of implementation as shown below
window.indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB ||
window.msIndexedDB;

window.IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction ||
window.msIDBTransaction;
window.IDBKeyRange = window.IDBKeyRange || window.webkitIDBKeyRange ||
window.msIDBKeyRange
if (!window.indexedDB) {
window.alert("Your browser doesn't support a stable version of IndexedDB.")
}

Open an IndexedDB database
Before creating a database, we have to prepare some data for the data base.let's start with
company employee details.
const employeeData = [
{ id: "01", name: "Gopal K Varma", age: 35, email: "contact@tutorialspoint.com" },
{ id: "02", name: "Prasad", age: 24, email: "prasad@tutorialspoint.com" }
];

Adding the data
Here adding some data manually into the data as shown below −
function add() {
var request = db.transaction(["employee"], "readwrite")
.objectStore("employee")
.add({ id: "01", name: "prasad", age: 24, email: "prasad@tutorialspoint.com" });
request.onsuccess = function(event) {
alert("Prasad has been added to your database.");
};
request.onerror = function(event) {
alert("Unable to add data\r\nPrasad is already exist in your database! ");
}
}

Retrieving Data
We can retrieve the data from the data base using with get
function read() {
var transaction = db.transaction(["employee"]);
var objectStore = transaction.objectStore("employee");
var request = objectStore.get("00-03");
request.onerror = function(event) {
alert("Unable to retrieve daa from database!");
};
request.onsuccess = function(event) {
if(request.result) {
alert("Name: " + request.result.name + ", Age: " + request.result.age + ",
Email: " + request.result.email);
}
else {
alert("Kenny couldn't be found in your database!");
}
};
}

Using with get, we can store the data in object instead of that we can store the data in cursor and
we can retrieve the data from cursor
function readAll() {

var objectStore = db.transaction("employee").objectStore("employee");
objectStore.openCursor().onsuccess = function(event) {
var cursor = event.target.result;
if (cursor) {
alert("Name for id " + cursor.key + " is " + cursor.value.name + ", Age: " +
cursor.value.age + ", Email: " + cursor.value.email);
cursor.continue();
}
else {
alert("No more entries!");
}
};
}

Removing the data
We can remove the data from IndexedDB with remove.Here is how the code looks like
function remove() {
var request = db.transaction(["employee"], "readwrite")
.objectStore("employee")
.delete("02");
request.onsuccess = function(event) {
alert("prasad entry has been removed from your database.");
};
}

HTML Code
To show all the data we need to use onClick event as shown below code −
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>IndexedDb Demo | onlyWebPro.com</title>
</head>
<body>
<button
<button
<button
<button

onclick="read()">Read </button>
onclick="readAll()"></button>
onclick="add()"></button>
onclick="remove()">Delete </button>

</body>
</html>

Final code should be as
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/javascript">
//prefixes of implementation that we want to test
window.indexedDB = window.indexedDB || window.mozIndexedDB ||
window.webkitIndexedDB || window.msIndexedDB;
//prefixes of window.IDB objects
window.IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction ||

window.msIDBTransaction;
window.IDBKeyRange = window.IDBKeyRange || window.webkitIDBKeyRange ||
window.msIDBKeyRange
if (!window.indexedDB) {
window.alert("Your browser doesn't support a stable version of IndexedDB.")
}
const employeeData = [
{ id: "00-01", name: "gopal", age: 35, email: "gopal@tutorialspoint.com" },
{ id: "00-02", name: "prasad", age: 32, email: "prasad@tutorialspoint.com" }
];
var db;
var request = window.indexedDB.open("newDatabase", 1);
request.onerror = function(event) {
console.log("error: ");
};
request.onsuccess = function(event) {
db = request.result;
console.log("success: "+ db);
};
request.onupgradeneeded = function(event) {
var db = event.target.result;
var objectStore = db.createObjectStore("employee", {keyPath: "id"});
for (var i in employeeData) {
objectStore.add(employeeData[i]);
}
}
function read() {
var transaction = db.transaction(["employee"]);
var objectStore = transaction.objectStore("employee");
var request = objectStore.get("00-03");
request.onerror = function(event) {
alert("Unable to retrieve daa from database!");
};
request.onsuccess = function(event) {
// Do something with the request.result!
if(request.result) {
alert("Name: " + request.result.name + ", Age: " + request.result.age +
", Email: " + request.result.email);
}
else {
alert("Kenny couldn't be found in your database!");
}
};
}
function readAll() {
var objectStore = db.transaction("employee").objectStore("employee");
objectStore.openCursor().onsuccess = function(event) {
var cursor = event.target.result;
if (cursor) {
alert("Name for id " + cursor.key + " is " + cursor.value.name + ",
Age: " + cursor.value.age + ", Email: " + cursor.value.email);
cursor.continue();
}
else {
alert("No more entries!");

}
};
}
function add() {
var request = db.transaction(["employee"], "readwrite")
.objectStore("employee")
.add({ id: "00-03", name: "Kenny", age: 19, email: "kenny@planet.org" });
request.onsuccess = function(event) {
alert("Kenny has been added to your database.");
};
request.onerror = function(event) {
alert("Unable to add data\r\nKenny is aready exist in your database! ");
}
}
function remove() {
var request = db.transaction(["employee"], "readwrite")
.objectStore("employee")
.delete("00-03");
request.onsuccess = function(event) {
alert("Kenny's entry has been removed from your database.");
};
}
</script>
</head>
<body>
<button
<button
<button
<button

onclick="read()">Read </button>
onclick="readAll()">Read all </button>
onclick="add()">Add data </button>
onclick="remove()">Delete data </button>

</body>
</html>

HTML5 - WEB MESSAGING
Web Messaging is the way for documents to separates browsing context to share the data without
Dom. It overrides the cross domain communication problem in different domains, protocols or
ports.
For example you want to send the data from your page to ad container which is placed at iframe
or voice-versa, in this scenario,Browser throws a security exception. With web messaging we can
pass the data across as a message event.

Message Event
Message events fires Cross-document messaging, channel messaging, server-sent events and web
sockets.it has described by Message Event interface.

Attributes

Attributes

Description

data

Contains string data

origin

Contains Domain name and port

lastEventId

Contains unique identifier for the current message event.

source

Contains to A reference to the originating document’s window

ports

Contains the data which is sent by any message port

Sending a cross-document message
Before send cross document message, we need to create a new web browsing context either by
creating new iframe or new window. We can send the data using with postMessage and it has two
arguments. They are as
message − The message to send
targetOrigin − Origin name

Examples
Sending message from iframe to button
var iframe = document.querySelector('iframe');
var button = document.querySelector('button');
var clickHandler = function(){
iframe.contentWindow.postMessage('The message to
send.','https://www.tutorialspoint.com);
}
button.addEventListener('click',clickHandler,false);

Receiving a cross-document message in the receiving document
var messageEventHandler = function(event){
// check that the origin is one we want.
if(event.origin == 'https://www.tutorialspoint.com'){
alert(event.data);
}
}
window.addEventListener('message', messageEventHandler,false);

Channel messaging
Two way communication between the browsing contexts is called channel messaging. It is useful
for communication across multiple origins.

The MessageChannel and MessagePort Objects
While creating messageChannel,it internally creates two ports to sending the data and forwarded
to another browsing context.
postMessage − Post the message throw channel
start − It sends the data
close − it close the ports
In this scenario, we are sending the data from one iframe to another iframe. Here we are invoking
the data in function and passing the data to DOM.

var loadHandler = function(){
var mc, portMessageHandler;
mc = new MessageChannel();
window.parent.postMessage('documentAHasLoaded','http://foo.example',[mc.port2]);
portMessageHandler = function(portMsgEvent){
alert( portMsgEvent.data );
}
mc.port1.addEventListener('message', portMessageHandler, false);
mc.port1.start();
}
window.addEventListener('DOMContentLoaded', loadHandler, false);

Above code, it is taking the data from port 2, now it will pass the data to second iframe
var loadHandler = function(){
var iframes, messageHandler;
iframes = window.frames;
messageHandler = function(messageEvent){
if( messageEvent.ports.length > 0 ){
// transfer the port to iframe[1]
iframes[1].postMessage('portopen','http://foo.example',messageEvent.ports);
}
}
window.addEventListener('message',messageHandler,false);
}
window.addEventListener('DOMContentLoaded',loadHandler,false);

Now second document handles the data by using the portMsgHandler function.
var loadHandler(){
// Define our message handler function
var messageHandler = function(messageEvent){
// Our form submission handler
var formHandler = function(){
var msg = 'add <foo@example.com> to game circle.';
messageEvent.ports[0].postMessage(msg);
}
document.forms[0].addEventListener('submit',formHandler,false);
}
window.addEventListener('message',messageHandler,false);
}
window.addEventListener('DOMContentLoaded',loadHandler,false);

HTML5 - CORS
Cross-origin resource sharing CORS is a mechanism to allows the restricted resources from
another domain in web browser
For suppose, if you click on HTML5- video player in html5 demo sections. it will ask camera
permission. if user allow the permission then only it will open the camera or else it doesn't open
the camera for web applications

Making a CORS request
here Chrome, Firefox, Opera and Safari all use the XMLHttprequest2 object and Internet Explorer
uses the similar XDomainRequest object, object.
function createCORSRequest(method, url) {
var xhr = new XMLHttpRequest();
if ("withCredentials" in xhr) {
// Check if the XMLHttpRequest object has a "withCredentials" property.

// "withCredentials" only exists on XMLHTTPRequest2 objects.
xhr.open(method, url, true);
}
else if (typeof XDomainRequest != "undefined") {
// Otherwise, check if XDomainRequest.
// XDomainRequest only exists in IE, and is IE's way of making CORS requests.
xhr = new XDomainRequest();
xhr.open(method, url);
}
else {
// Otherwise, CORS is not supported by the browser.
xhr = null;
}
return xhr;
}
var xhr = createCORSRequest('GET', url);
if (!xhr) {
throw new Error('CORS not supported');
}

Event handles in CORS
Event Handler

Description

onloadstart

Starts the request

onprogress

Loads the data and send the data

onabort

Abort the request

onerror

request has failed

onload

request load successfully

ontimeout

time out has happened before request could complete

onloadend

When the request is complete either successful or failure

Example of onload or onerror event
xhr.onload = function() {
var responseText = xhr.responseText;
// process the response.
console.log(responseText);
};
xhr.onerror = function() {
console.log('There was an error!');
};

Example of CORS with handler
Below example will show the example of makeCorsRequest and onload handler
// Create the XHR object.
function createCORSRequest(method, url) {
var xhr = new XMLHttpRequest();
if ("withCredentials" in xhr) {
// XHR for Chrome/Firefox/Opera/Safari.

xhr.open(method, url, true);
}
else if (typeof XDomainRequest != "undefined") {
// XDomainRequest for IE.
xhr = new XDomainRequest();
xhr.open(method, url);
}
else {
// CORS not supported.
xhr = null;
}
return xhr;
}
// Helper method to parse the title tag from the response.
function getTitle(text) {
return text.match('<title>(.*)?</title>')[1];
}
// Make the actual CORS request.
function makeCorsRequest() {
// All HTML5 Rocks properties support CORS.
var url = 'http://www.tutorialspoint.com';
var xhr = createCORSRequest('GET', url);
if (!xhr) {
alert('CORS not supported');
return;
}
// Response handlers.
xhr.onload = function() {
var text = xhr.responseText;
var title = getTitle(text);
alert('Response from CORS request to ' + url + ': ' + title);
};
xhr.onerror = function() {
alert('Woops, there was an error making the request.');
};
xhr.send();
}

HTML5 - WEB RTC
Web RTC introduced by World Wide Web Consortium W3C. That supports browser-to-browser
applications for voice calling, video chat, and P2P file sharing.
If you want to try out? web RTC available for Chrome,opera,and firefox. A good place to start is the
simple video chat application at here.Web RTC implements three API's as shown below −
MediaStream − get access to the user's camera and microphone.
RTCPeerConnection − get access to audio or video calling facility.
RTCDataChannel − get access to peer-to-peer communication.

MediaStream
The MediaStream represents synchronized streams of media, For an example, Click on HTML5
Video player in HTML5 demo section or else click here.
The above example contains stream.getAudioTracks and stream.VideoTracks. If there is no audio
tracks, it returns an empty array and it will check video stream,if webcam connected,

stream.getVideoTracks returns an array of one MediaStreamTrack representing the stream from
the webcam. A simple example is chat applications, a chat applications gets stream from web
camera, rear camera, microphone.
Sample code of MediaStream
function gotStream(stream) {
window.AudioContext = window.AudioContext || window.webkitAudioContext;
var audioContext = new AudioContext();
// Create an AudioNode from the stream
var mediaStreamSource = audioContext.createMediaStreamSource(stream);
// Connect it to destination to hear yourself
// or any other node for processing!
mediaStreamSource.connect(audioContext.destination);
}
navigator.getUserMedia({audio:true}, gotStream);

Screen capture
It's also possible in chrome browser with mediaStreamSource and it required HTTPS. This feature
is not yet available in opera. Sample demo is available at here

Session Control, Network & Media Information
Web RTC required peer-to-peer communication between browsers. This mechanism required
signalling, network information, session control and media information. Web developers can
choose different mechanism to communicate between the browsers such as SIP or XMPP or any
two way communications.A sample example of XHR is here.
Sample code of createSignalingChannel
var signalingChannel = createSignalingChannel();
var pc;
var configuration = ...;
// run start(true) to initiate a call
function start(isCaller) {
pc = new RTCPeerConnection(configuration);
// send any ice candidates to the other peer
pc.onicecandidate = function (evt) {
signalingChannel.send(JSON.stringify({ "candidate": evt.candidate }));
};
// once remote stream arrives, show it in the remote video element
pc.onaddstream = function (evt) {
remoteView.src = URL.createObjectURL(evt.stream);
};
// get the local stream, show it in the local video element and send it
navigator.getUserMedia({ "audio": true, "video": true }, function (stream) {
selfView.src = URL.createObjectURL(stream);
pc.addStream(stream);
if (isCaller)
pc.createOffer(gotDescription);
else
pc.createAnswer(pc.remoteDescription, gotDescription);
function gotDescription(desc) {
pc.setLocalDescription(desc);
signalingChannel.send(JSON.stringify({ "sdp": desc }));
}
});

}
signalingChannel.onmessage = function (evt) {
if (!pc)
start(false);
var signal = JSON.parse(evt.data);
if (signal.sdp)
pc.setRemoteDescription(new RTCSessionDescription(signal.sdp));
else
pc.addIceCandidate(new RTCIceCandidate(signal.candidate));
};

I understand you would not be satisfied with this quick guide, so I request to explore HTML5
Tutorial because it is a big change in HTML4 version and can not be covered in a short note.
Processing math: 11%

</pre><hr>Source Exif Data: <br /><pre>File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.4
Linearized                      : No
Title                           : HTML5 Quick Guide
Creator                         : 
Producer                        : wkhtmltopdf
Create Date                     : 2015:09:30 12:49:32-05:00
Page Count                      : 62
</pre>
<small>EXIF Metadata provided by <a href="https://exif.tools/">EXIF.tools</a></small>

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