value JavaScript (JS) Example: HTML DOM Objects – Button Object – value JavaScript (JS) Example
value JavaScript (JS) Example: HTML DOM Objects – Button Object – value JavaScript (JS) Example
Purpose: – Illustrates the JavaScript syntax for the Button Object value Property .
Prerequistes:
- Install Visual Web Developer 2008
Syntax: ButtonObject.value=”texttodisplay” – Allows you to access the text to display on button.
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 “DOMButton”
- Right-click folder named “HTMLDOMObjects” in solution explorer;
- add new folder;
- name of folder should be: DOMButton
- Add New subfolder to “DOMButton” subfolder named “ButtonObjectProperties”
- Right-click subfolder named “DOMButton” in solution explorer;
- add new folder;
- name of folder should be: ButtonObjectProperties
- Add HTML Page Named value to ButtonObjectProperties subfolder
- Right-click ButtonObjectProperties subfolder;
- add new item;
- Select HTML Page
- HTML Page name should be value
- Click on copy code in code below to copy code into HTML Page value.htm
- Right-click on HTML page value.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: value </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:xx-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"> <div style="background-color:Yellow;border-color:black;border-style:solid;border-width:1px;"> click Buttons to change value of button object:</div><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" class="myButtons" value="button1 - value=button1" onclick="javascript: Set_Cookie( 'mycookie', '1', 30, '/', '', '' ); window.location.reload();" /><br /><br /> <input id="Button2" type="button" class="myButtons" value="button2 - value=button2" onclick="javascript: Set_Cookie( 'mycookie', '2', 30, '/', '', '' ); window.location.reload();"/><br /><br /> <input id="Button3" type="button" class="myButtons" value="button3 - value=button3" onclick="javascript: Set_Cookie( 'mycookie', '3', 30, '/', '', '' ); window.location.reload();"/><br /><br /> <script type="text/javascript"> //***************************************************** // DOM Objects //***************************************************** //***************************************************** // *** Button Object Properties *** //***************************************************** //***************************************************** // value //***************************************************** // SYNTAX: // object.value="value" Allows you to retrieve or assign value for the text displayed for a button // Two ways to retrieve value document.write("<div style=\"border-style:solid\"><strong>Demonstrating Two Ways to Retrieve Property for Button1</strong><br />") // 1. GetElementsByTagName myObject=document.getElementsByTagName('input')[0]; document.write("Using getElementsByTagName: " + myObject.value); document.write("<br />"); // 2. GetElementById document.write("Using getElementById: "); document.write(document.getElementById('Button1').value); document.write("</div><br />"); document.write("<br />"); // Two ways to assign value if (Get_Cookie('mycookie')) { ButtonNum = (Get_Cookie('mycookie')); } else { ButtonNum = '1'; } // 1. GetElementById if (ButtonNum == '2') { document.write("<div style=\"border-style:solid\"><strong>Demonstrating Assigning Property with GetById for Button2</strong><br />") document.getElementById('Button2').value = "button2 - value=newButton2" document.getElementById('Button2').className = "myButton2" document.write("Button2 value changed to value=newButton2: " + document.getElementById('Button2').value + "</div><br />"); } // 2. GetElementsByTagName if (ButtonNum == '3') { document.write("<div style=\"border-style:solid\"><strong>Demonstrating Assigning Property with GetElementsByTagName for Button3</strong><br />") myThirdButton = document.getElementsByTagName('input')[2]; myThirdButton.className = "myButton3" myThirdButton.value = "button3 - value=newButton3" document.write("Button3 value changed to value=newButton3: " + myThirdButton.value + "</div>"); } </script> </body> </html> |