getElementById returning no length for existing id

]|V|[agnus · 11-26-2004, 11:01 PM

Is there something wrong with my script? Typo?

Code:

function accite() {
	bq = document.getElementById("content").getElementsByTagName("blockquote");
	q = document.getElementById("content").getElementsByTagName("q");
	alert(
		"<blockquote /> = " + bq.length +
		"<q /> = " + q.length
	);
}

It's saying "document.getElementById('content') has no properties", and yes, I definitely have a <div id="content" />.

liorean · 11-26-2004, 11:04 PM

Show us more of your source. Specifically, show us the HTML in question.

]|V|[agnus · 11-26-2004, 11:44 PM

Here is an example page: http://sethrasmussen.com/index.php?p=86

I should note that I am having the problem in Firefox and IE. It actually seems to work fine in Opera, though. Dunno about more yet.

hemebond · 11-26-2004, 11:59 PM

If you only have one instance of the blockquote or q elements, getElementsByTagName will return that object instead of an array of objects.

Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
	<head>
		<title>48059</title>
	</head>
	<body>
		<div id="content">
			<blockquote></blockquote>
			<q></q>
		</div>

		<script type="text/javascript">
			var bq = document.getElementById("content").getElementsByTagName("blockquote");
			if(bq.length == undefined)
			{
				bq = new Array(bq);
			}

			var q = document.getElementById("content").getElementsByTagName("q");
			if(q.length == undefined)
			{
				q = new Array(q);
			}

			alert(
				"<blockquote /> = " + bq.length +
				"<q /> = " + q.length
			);
		</script>
	</body>
</html>

]|V|[agnus · 11-27-2004, 12:00 AM

Well, okay, but the problem is that IE and Firefox are choking before they even get to that. They bomb on "getElementById('content')"

Willy Duitt · 11-27-2004, 12:02 AM

For one, your calling the function window.onload is premature and the content division has not yet been written to the page... Sans the error... Try body.onload instead...

Code:

function accite() {
	bq = document.getElementById("content").getElementsByTagName("blockquote");
	q = document.getElementById("content").getElementsByTagName("q");
	alert(
		"<blockquote /> = " + bq.length +
		"<q /> = " + q.length
	);
}

// init
function init () {accite();}
window.onload=init();

.....Willy

]|V|[agnus · 11-27-2004, 12:05 AM

"body is not defined"

Willy Duitt · 11-27-2004, 01:11 AM

You can't change window.onload = init() with body.onload = init() in the HEAD because well.... the body has not been written to the page yet...

Try: <body onload="init()">

]|V|[agnus · 11-27-2004, 01:44 AM

very well, but how can i avoid adding the event handler to the structure?

document.getElementsByTagName("body").onload=init(); doesn't seem to work.

perhaps, document.getElementById("sethrasmussen-dot-com").onload=init(); ?

assuming of course that's the name of the body element?

]|V|[agnus · 11-27-2004, 01:45 AM

no no that doesn't work... perhaps i include a file at the end of every page with sort of _exit scripts?

Willy Duitt · 11-27-2004, 02:06 AM

Quote:

Originally Posted by ]|V|[agnus

very well, but how can i avoid adding the event handler to the structure?

document.getElementsByTagName("body").onload=init(); doesn't seem to work.

perhaps, document.getElementById("sethrasmussen-dot-com").onload=init(); ?

assuming of course that's the name of the body element?

getElementsByTagName returns an array....
Try: document.getElementsByTagName("body")[0].onload=function(){init()};

]|V|[agnus · 11-27-2004, 03:06 AM

well i'm just doing the onload attribute for now. what i'm trying to do with my script is to insert links after blockquotes and quotes that have their href's generated by the blockquote or quote's cite attributes. i'm getting no errors with the following, but no links are inserted:

Code:

function accite() {
	d = document;
	bq = d.getElementById("content").getElementsByTagName("blockquote");
	q = d.getElementById("content").getElementsByTagName("q");
	// cite blockquotes
	for(i=0;i<bq.length;i++){
		newP=d.createElement("p");
		newA=d.createElement("a");
		newA.setAttribute("href",bq[i].getAttribute("cite"));
		newP.appendChild(newA);
		bq[i].appendChild(newP);
	}
}

that code is being run on the same link from above.

Willy Duitt · 11-27-2004, 03:02 PM

Although you are now calling the accite function body.onload.... You are still using window.onload to call the init function which in turn calls the accite and thus is still throwing the aforementioned error...

This could be causing a conflict but is hard for me to tell since your entire page does not work for me using IE6... There is much text overlayed upon other text, I can not scroll, view source does not open notepad although the context menu is there and the page seems to take a lot of cpu to display....

Anyways, it is hard for me to see what is going on or what it is supposed to look like...

.....Willy

]|V|[agnus · 11-27-2004, 05:03 PM

Quote:

Originally Posted by Willy Duitt

Although you are now calling the accite function body.onload.... You are still using window.onload to call the init function which in turn calls the accite and thus is still throwing the aforementioned error...

No, I'm not.

Quote:

Originally Posted by Willy Duitt

This could be causing a conflict

What conflict? I am not getting any errors anymore, but the desired effect is not happening. I think it's because I am trying to use appendChild on a new element that has not been added to the tree yet itself. Yes?

Quote:

Originally Posted by Willy Duitt

but is hard for me to tell since your entire page does not work for me using IE6... There is much text overlayed upon other text, I can not scroll, view source does not open notepad although the context menu is there and the page seems to take a lot of cpu to display....

Anyways, it is hard for me to see what is going on or what it is supposed to look like...

...

Quote:

Originally Posted by sethrasmussen.com/in/colophon.php

That said, users of Internet Explorer can expect persistent bugginess, as this site makes use of modern techniques, the bulk of which IE only partially supports. Despite its massive market share, I've decided not to go out of my way to accomodate this archaic browser since the rest of the competition has continued to innovate and move forward. This site is about progress, not market share.

Willy Duitt · 11-27-2004, 05:20 PM

If you are no longer calling the init function window.onload you changed it since I last looked at it shortly after you posted "that code is being run on the same link from above".... the window.onload = init() is in your external javascript file...

And FWIW: What you call modern browsers I call equally buggy if not moreso than IE... Heck, if Firefox is so wonderful why did this latest release break nearly every plugin that was made in the past? Now, all those plugins need to be patched... How long can we expect that to continue?

Besides, IE is one of the most forgiving browsers there is... If your code completely breaks using IE, there is something wrong and the quick look I took at your code shows no indication of cutting-edge code writing....

That being said, I was only trying to help you by pointing out some obvious mistakes... If you have removed the window.onload from the external file, great for you but roll your eyes at someone else....

.....Willy