JavaScript (JS) id Example: HTML DOM Objects – Body Object – JavaScript (JS) id Example
JavaScript (JS) id Example: HTML DOM Objects – Body Object – JavaScript (JS) id Example
Purpose: – Illustrates the JavaScript syntax for the Body Object id Property .
Prerequistes:
- Install Visual Web Developer 2008
Syntax: BodyObject.id=”idname” – Allows you to access the id for a BodyObject.
Restrictions: None
Notes:
- You can build your own library of syntax examples by using same web site over and over and just add new files to it.
Instructions:
- Use Visual Web Developer 2008
- Create new web site;
- Click File/New Web Site
- Select ASP.NET Website Template
- Select C-Sharp for language
- name of Web Site could be JavaScript_Syntax.
- Add New folder named “HTMLDOMObjects”
- Right-click project name in solution explorer;
- add new folder;
- name of folder should be: HTMLDOMObjects
- Add New subfolder to “HTMLDOMObjects” folder named “DOMBody”
- Right-click folder named “HTMLDOMObjects” in solution explorer;
- add new folder;
- name of folder should be: DOMBody
- Add New subfolder to “DOMBody” subfolder named “BodyObjectProperties”
- Right-click subfolder named “DOMBody” in solution explorer;
- add new folder;
- name of folder should be: BodyObjectProperties
- Add HTML Page Named id to BodyObjectProperties subfolder
- Right-click BodyObjectProperties subfolder;
- add new item;
- Select HTML Page
- HTML Page name should be id
- Click on copy code in code below to copy code into HTML Page id.htm
- Right-click on HTML page id.htm and select view in browser
< !DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>IdealProgrammer.com: id </title>
<!--
***************************************************
* This example is from http://idealprogrammer.com *
***************************************************
-->
<style type="text/css" id="myStyle">
.myButtons
{
font-size:large;
color:red;
}
.myButtons input
{
color:Blue
}
.myButton2
{
font-size:small;
}
.myButton2 input
{
font-style :italic
}
.myButton3
{
background-color:#d0e4fe;
}
.myButton3 input
{
font-weight:600
}
</style>
<script type="text/javascript">
//****************************************************************
// Set Cookie
//****************************************************************
function Set_Cookie( name, value, expires, path, domain, secure )
{
// set time, it's in milliseconds
var today = new Date();
today.setTime( today.getTime() );
/*
if the expires variable is set, make the correct
expires time, the current script below will set
it for x number of days, to make it for hours,
delete * 24, for minutes, delete * 60 * 24
*/
if ( expires )
{
expires = expires * 1000 * 60 * 60 * 24;
}
var expires_date = new Date( today.getTime() + (expires) );
document.cookie = name + "=" +escape( value ) +
( ( expires ) ? ";expires=" + expires_date.toGMTString() : "" ) +
( ( path ) ? ";path=" + path : "" ) +
( ( domain ) ? ";domain=" + domain : "" ) +
( ( secure ) ? ";secure" : "" );
}
//****************************************************************
// Get Cookie
//****************************************************************
// this fixes an issue with the old method, ambiguous values
// with this test document.cookie.indexOf( name + "=" );
function Get_Cookie(check_name) {
// first we'll split this cookie up into name/value pairs
// note: document.cookie only returns name=value, not the other components
var a_all_cookies = document.cookie.split(';');
var a_temp_cookie = '';
var cookie_name = '';
var cookie_value = '';
var b_cookie_found = false; // set boolean t/f default f
for (i = 0; i < a_all_cookies.length; i++) {
// now we'll split apart each name=value pair
a_temp_cookie = a_all_cookies[i].split('=');
// and trim left/right whitespace while we're at it
cookie_name = a_temp_cookie[0].replace(/^\s+|\s+$/g, '');
// if the extracted name matches passed check_name
if (cookie_name == check_name) {
b_cookie_found = true;
// we need to handle case where cookie has no value but exists (no = sign, that is):
if (a_temp_cookie.length > 1) {
cookie_value = unescape(a_temp_cookie[1].replace(/^\s+|\s+$/g, ''));
}
// note that in cases where cookie is initialized but no value, null is returned
return cookie_value;
break;
}
a_temp_cookie = null;
cookie_name = '';
}
if (!b_cookie_found) {
return null;
}
}
</script>
</head>
<body id="myBodyID" class="myButtons">
Please click Buttons to change id assigned to body:<br /><br />
<!--using onclick to set a cookie and reload page;
when page is reloading, we check that cookie to assign different styles to body
-->
<input id="Button1" type="button" value="button" onclick="javascript: Set_Cookie( 'mycookie', '1', 30, '/', '', '' ); window.location.reload();" /><br /><br />
<input id="Button2" type="button" value="button - id2" onclick="javascript: Set_Cookie( 'mycookie', '2', 30, '/', '', '' ); window.location.reload();"/><br /><br />
<input id="Button3" type="button" value="button - id3" onclick="javascript: Set_Cookie( 'mycookie', '3', 30, '/', '', '' ); window.location.reload();"/><br /><br />
<script type="text/javascript">
//*****************************************************
// DOM Objects
//*****************************************************
//*****************************************************
// *** Body Object Properties ***
//*****************************************************
//*****************************************************
// id
//*****************************************************
// SYNTAX:
// object.id="id" Allows you to retrieve or assign id for
// body
//*****************************************************
// Two ways to retrieve id
//*****************************************************
document.write("<strong>Demonstrating Two Ways to Retrieve Property</strong><br />")
// 1. GetElementsByTagName
myObject=document.getElementsByTagName('body')[0];
document.write("1. Using getElementsByTagName: " + myObject.id);
document.write("<br />");
// 2. GetElementById
document.write("2. Using getElementById: ");
document.write(document.getElementById('myBodyID').id);
document.write("<br />");
document.write("<br />");
//*****************************************************
// Two ways to assign id
//*****************************************************
// using cookies to change property and style on the fly
if (Get_Cookie('mycookie')) {
ButtonNum = (Get_Cookie('mycookie'));
}
else {
ButtonNum = '1';
}
// 1. GetElementById
if (ButtonNum == '2') {
document.write("<strong>Demonstrating Assigning Property with GetById</strong><br />")
document.getElementById('myBodyID').className = "myButton2"
document.getElementById('myBodyID').id = "myID2"
document.write("Body id changed to myID2: " + document.getElementById('myID2').id + "<br />");
}
// 2. GetElementsByTagName
if (ButtonNum == '3') {
document.write("<strong>Demonstrating Assigning Property with GetElementsByTagName</strong><br />")
myThirdButton = document.getElementsByTagName('body')[0];
myThirdButton.className = "myButton3";
myThirdButton.id = "myID3";
document.write("Body id changed to myID3: " + myThirdButton.id);
}
</script>
</body>
</html> |
