Setting body onload without using the tag

Question

I am trying to a function to trigger once the body loads. I know that you can do this from the body tag, but I would prefer to do this from JS if this is possible.

For example: document.getElementsByTagName('body').onload = someFunc();

This does not work for me, but I think it shows what I essentially want to do.

EDIT:

I have tried the answers, what seems to be the issue is that it is calling the function before the elements it uses in the body tag are loaded, even if I put the script tags inside the body. This is what it needs to do:

var buttonElements = document.getElementsByClassName('button');

And if I do:

alert(buttonElements)

It will pop up 0, but when I create a variable in the console, it will successfully populate it with the elements.

You should try window.onload http://stackoverflow.com/questions/588040/window-onload-vs-document-onload — Ray, Dec 27 '12 at 18:42
"someFunc" should be `someFunc`, no? And you can use shortcut form `document.body`, too. — raina77ow, Dec 27 '12 at 18:42
Also the `body` has to exist before trying to access it : ). — Teemu, Dec 27 '12 at 18:59
possible duplicate of [Attach a body onload event with JS](http://stackoverflow.com/questions/1235985/attach-a-body-onload-event-with-js) — EdChum, Dec 28 '12 at 00:53

score 5 · Accepted Answer · answered Dec 27 '12 at 18:42

5

What you've got will almost work, but you have to import your JavaScript at the end of the <body> tag, and you have to index the first result:

document.getElementsByTagName('body')[0].onload = someFunc;

answered Dec 27 '12 at 18:42

Pointy

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Sarfraz · Answer 2 · 2012-12-27T18:47:44.290

5

Like so:

window.onload = someFunc;

If however, your function accepts arguemnts, you would need anonymous function like this:

window.onload = function(){
    someFunc(arg1, arg2);
}

BTW, other than fix that @Pointy mentioned for your code, you can also do:

document.body.onload = someFunc;

edited Dec 27 '12 at 18:47

answered Dec 27 '12 at 18:42

Sarfraz

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score 2 · Answer 3 · answered Dec 27 '12 at 18:42

2

Dont use quotes... "someFunc"() won't work if you try to run it anyways.

window.onload = someFunc;

answered Dec 27 '12 at 18:42

jeremy

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score 2 · Answer 4 · answered Dec 27 '12 at 18:45

2

If you use jQuery:

$(document).ready(function () {
    callMyFunction();
});

answered Dec 27 '12 at 18:45

Jim Neff

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Setting body onload without using the tag

4 Answers4

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