Generic onload
Version 1.1 - 1st November 2004
This script is an encapsulated onload function that doesn't
interfere with other window.onload or
<body onload> functions on the same page.
The script works in all modern browsers (with javascript enabled).
The demo uses alert() dialogues
to demonstrate the onload methods firing. If scripting
(or this script) is not supported, nothing will happen.
Get the script
Download the zipfile [1K] and unzip it into your site directory, then you can either include the script on your page as it is:
<!-- Generic onload by Brothercake - http://www.brothercake.com/ -->
<script type="text/javascript" src="onload.js"></script>
or copy the code into another script, and work with it from there:
//GO1.1
///////////////////////////////////////
//
// Generic onload by Brothercake
// http://www.brothercake.com/
//
///////////////////////////////////////
//onload function
function generic()
{
alert('Generic onload function');
};
//setup onload function
if(typeof window.addEventListener != 'undefined')
{
//.. gecko, safari, konqueror and standard
window.addEventListener('load', generic, false);
}
else if(typeof document.addEventListener != 'undefined')
{
//.. opera 7
document.addEventListener('load', generic, false);
}
else if(typeof window.attachEvent != 'undefined')
{
//.. win/ie
window.attachEvent('onload', generic);
}
//** remove this condition to degrade older browsers
else
{
//.. mac/ie5 and anything else that gets this far
//if there's an existing onload function
if(typeof window.onload == 'function')
{
//store it
var existing = onload;
//add new onload handler
window.onload = function()
{
//call existing onload function
existing();
//call generic onload function
generic();
};
}
else
{
//setup onload function
window.onload = generic;
}
}
There may be limitations on where this can go, depending on the level of browser support you need ...
Browser notes
Mac/IE5 doesn't support
any truly encapsulated onload methods, so the script has
to use window.onload. But it does this with sensitivity - if your
page is already using a window or <body onload> handler,
the script will copy and call that first, before the generic onload kicks in.
It can only do this if the handler has already been defined, therefore this script must come after it in the source-code, or the generic onload won't be called.
You can of course simplify your life, and just remove
the final else{} condition - degrading
Mac/IE5 and older browsers to unsupported.
Then it won't matter where the script is, or how many of them
them you use.
![[php]](/images/php.gif "Uses PHP")