[Chris O'Brien]

OK, I suppose I'd be able to look this up somewhere else, but I may as well ask here

Does anyone know why I've been forced to using childNodes->item(number) instead of childNodes[number] as one would expect? Is this a bug in php 5RC3, or am I missing something? I can't imagine why the php team would stray from the standard in this way, so, hopefully, it is purely a mild oversight in this release...

Anyone know for sure?

[larkost]

The PHP DOM is a series of classes, not a language construct, so you have to work with the class structure. It builds a nested series of objects, and then you work with those objects, they are allowing you to work with the DOM, not implementing it.

[Chris O'Brien]

That doesn't answer the question. I realise that it's a nested series of objects I'm working on, I know what DOM stands for and how things work, so it's pretty explanatory.
However, in moving from php4's implementation of DOMXML, to PHP5's, they've (fantastically - it was pants before) adhered to the W3C's naming convention etc for most things, but have seemed to neglect the referencing convention of [num] as I mentioned in my first post. Now, in at least one tutorial (and another external reference) I've seen, childNodes[num] has been used. I was wondering why I couldn't get it to work, despite the fact it seems to be documented that I should be able to. It's quite annoying, since I use XML DOM parsing all the time in other languages, where it does work.

[larkost]

You do know that the DOM does not require anything about the syntax of the language used to access it, yes? And that is what you are talking about, syntax. The W3C says nothing about this... they don't even require that frameworks that expose the DOM use their names for the functions.

PHP already has a meaning for $variableName[reference] in its syntax... and it is not quite the same thing as in JavaScript. PHP has a different syntax than JavaScript. $variableName->function[] does not exist in PHP so far as I can tell... and making it work simply because it looks like JavaScript is not a good reason to break the language. PHP is not JavaScript (ECMA Script).

I am not sure where you are getting your documentation/how-to's... but I have not seen anything like that on the (sparse) documentation on php.net... and that is the official source.

[Chris O'Brien]

Ouch, just read my reply - that was quite rude. Apologies, I was drunk enough that I don't remember typing that.

Anyhoo, I can't actually find the article where it did reference the childNodes with the [] syntax, but when I do, I'll post it, just for reference. I didn't know that the W3C's syntax wasn't a requirement - I presumed it was and hence the move from get_elements_by_tagname (etc) in php4 to getElementsByTagName in php5...

So my original question is just a question of syntax. I understand that php uses ->item() for an object collection, and I never once hinted that php was the same as javascript... I was just wondering why they use the same naming conventions for methods that the W3C spec recommends but not referencing syntax. It isn't a problem (obviously) just a quick question as to why.

I suppose, thinking about it, my question would also encompass why they don't use the . notation instead of ->, and that would be silly.

Anyhoo - 'twas a bit of a dumb question, but I was thrown by an article I read which used [] in dealing with php (I'll have to find that...).

Edit:
Now I remember where I got the impression you can use childNodes[]. It was at this page. However, since it's not in English, I may have gotten the wrong end of the stick.

[Millennium]

Does PHP support operator overloading? If not, then there's your answer; by implementing it as a class, they ensured that they couldn't do the childNodes[number] method.

To be honest, I find that the DOM has little use outside of Web pages; the same is true for SAX. Use them to read your document in, of course, but then build your own API on top of that. As long as your API calls out only to the standard APIs (SAX or DOM), you retain the porrtability and interoperability advantages of those standards, but everything above that layer will be much easier to work with.

[Chris O'Brien]

Just found out that it's SimpleXML that uses childNodes[num] syntax rather than DOMXML...

[Oisín]

Originally posted by Black Book:
Edit:
Now I remember where I got the impression you can use childNodes[]. It was at this page. However, since it's not in English, I may have gotten the wrong end of the stick.

Nope, you seem to have got it right enough, as far as I can tell (which, admittedly, isn't far - I believe I am what can be referred to as a PHP dummy; and a DOM dummy (a DOMmy?) as well)...

But any-old-how, he does use $node->childNodes[1]->nodeValue; etc. in that example, and it doesn't seem not to work for him (I mean, he wouldn't have published it if it didn't, would he?)