Applied component i unit 2

Applied Component I
Unit II
•Introduction of java-script
•Java-script in web browser
•Forms and form elements
•String manipulation

1.Introduction to java-script
• Java-script is a powerful client level scripting
languages
• Java-script is not java
• Java-script is a best supported scripting language
for many browsers
• It can be written inside <script> tag or in file with
extension .js
• JavaScript is usually embedded directly into
HTML pages
• JavaScript is Case Sensitive

How to write java-script
<html>
<head>
<script language="javascript">
function call()
{
alert("do u have any problem! hold on");
alert("lets start learning java-script");
}
</script>
</head>
<body>
<input type="button" value="simple button" onclick="call()">
</body>
</html>

string objects
• The main purpose of String Object in
JavaScript is for storing text.
math objects
• The main purpose of math object in javaScript is
to perform math operation like sin,cos,tan
operations

array object
• It is a array handler in javascript
Date object
• It gives access to date method, for displaying and
setting date

window Object
• The window object represents the browser’s
frame or window, in which your web page is
contained
• via the properties of the window object you can
find out what browser is running, the pages the
user has visited, the size of the browser window,
the size of the user’s screen
• The window object is a global object, which
means you don’t need to use its name to access
its properties and methods
– window.alert(“Hello class!”);
– Window.defaultStatus = “see your status bar”

history Object
• The history object keeps track of each page
that the user visits
• This list of pages is commonly called the
history stack for the browser
• It enables the user to click the browser’s Back
and Forward buttons to revisit pages
• the history object has the back() and forward()
methods.
• The history object also has the go() method.

• history.back();
– one page back
• history.forward();
– One page forward
• history.go(-3);
– three page back
• history.go(3);
– Three page forward

location Object
• The location object contains lots of potentially
useful information about the current page’s
location.
– it contain the URL (Uniform Resource Locator) for
the page
– server hosting
– port number of the server connection
– the protocol used

Navigate using location object
• You can navigate to another page in two ways
– location object’s href property
– location object’s replace() method
• replace() method removes the current page
from the history stack and replaces it with the
new page
• href property simply adds the new page to the
top of the history stack

Navigator object
• navigator object contains lots of information
about the browser and the operating system
in which it’s running.

document Object—The Page Itself
• The document object has a number of
properties associated with it, which are also
arrays. The main ones are the forms, images,
and links arrays.
– document.bgColor=“green”;
– document.images.length
• This will return how many image are on web page
– document.images[“image1”].
• It is the array of images of name “image1”

Events and event handling
• Basic html event
– onclick=”alert(‘You Clicked?’)”
– Onload=“”
– Onunload=“”
• window.document.links["anc1"].onclick =
linkclick;
– Special event handler has to be load after full html
page is cached

Forms and form elements
• document.forms.length;
– Returns count of form tags on document
• Document.form1.button1.value=“hello”;
– Changes the value of button1
• document.form1.txt1.focus();
– Takes focus on txt1(textbox)
• document.form1.txt1.select();
– Selects all text in txt1(textbox)

Windows and frames
• var newWindow =
window.open(myURL,”myWindow”,”width=12
5,height=150,resizable”);
• newWindow.resizeTo(350,200);
– resize your window to 350 pixels wide by 200
pixels
• newWindow.moveTo(100,400);
– move it so it’s 100 pixels from the left of the
screen and 400 pixels from the top

• newWindow.resizeBy(100,200);
– increase the size of newWindow by 100 pixels
horizontally and 200 pixels vertically
• newWindow.moveBy(20,50);
– move the newWindow by 20 pixels horizontally
and 50 pixels vertically

Dynamic html
• DHTML is the manipulation of an HTML
document after it is loaded into the browser,
and the most common way to manipulate the
document is by changing the way HTML
elements look

Accessing Elements
• The Document Object Model (DOM) holds the
ability you need to find and access HTML
elements; the DOM is a hierarchical tree, and
you can certainly climb it, inspect every
branch and leaf, and find what you’re looking
for
• document.getElementById(“divAdvert”)

Changing Appearances
• document.getElementById(“divAdvert”).style.
color = “red”

Positioning and Moving Content
• document.getElementById("div1").style.left =
"100px";
• document.getElementById("div1").style.top =
"200px";

Additional String Methods
• split() Method
– var myString = “A,B,C”;
– var myTextArray = myString.split(‘,’);
• replace() Method
– var myString = “The event will be in May, the 21st
of June”;
– myCleanedUpString =
myString.replace(“May”,”June”);

• search() Method
– var myString = “Beginning JavaScript, Beginning
Java, Professional JavaScript”;
– alert(myString.search(“Java”));
• alert box that occurs will show the value 10,
which is the character position of the J in the
first occurrence of Java

• match() Method
– var myString = “1997, 1998, 1999, 2000, 2000,
2001, 2002”;
– myMatchArray = myString.match(“2000”);
– alert(myMatchArray.length);
• instead of returning the position at which a
match was found, it returns an array.

Regular expression
• A regular expression is an object that
describes a pattern of characters.
• Regular expressions are used to perform
pattern-matching and "search-and-replace"
functions on text.
• syntax
– var txt=/pattern/modifiers;
– var txt=new RegExp(pattern,modifiers);

Applied component i unit 2

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