xml &amp; php

xml & php

nitm

hi all.
here's what i want to do:
open a xml file (on the server), add a node and save the file.
here's what i did:

if (!$dom = domxml_open_file("blah.xml")) {
    echo "no good";
    exit;
}
$root = $dom->document_element();
$node = $dom->create_element("entry");
$new_node = $dom->append_child($node);
$new_node->set_attribute("id", "1");
$dom->dump_file("blah.xml",false,true);

this does not work at all!
why?
thanks.

Weedpacket

Try reading this first.

nitm

what did i do wrong?
i guess you did not like my post, but why?

Weedpacket

Well, you didn't say what it was doing; whether or not you got any error messages (and if you did, what they were); you didn't say what steps you took to try and diagnose the problem (e.g., check that the extension is properly installed) and what the results were; you didn't mention what version of PHP you're using; you haven't indicated whether the manual cites any differences about the operation of the extension; in fact, you haven't indicated that you've many any attempt to solve the problem yourself (if you don't say what you've already tried and what the results were, a lot of people might suggest things you've already tried. If all you keep doing in response is "I've already tried that and it didn't work", you'll just annoy them.) You've basically taken a photo of your car, emailed it to your mechanic (or rather, posted it up for mechanics to look at it), and asked why it wouldn't start.

But I suggest you read those guidelines again, because I'm starting to repeat what's in there.

nitm

i'm new here and new with php so sorry for that...

let's start with the php itself, i don't know which version of php i'm using because it's not on my computer.. i'm doing this script for a friend and i'm doing everything on his server (host: media temple).

i want to use only the xml dom functions and well, that is installed for sure because i don't get any error messages.

i know that the script opens the existing xml file with the parser, the problem is the saving part...
i've been sitting on the docs all nite to understand what's wrong, i didn't find it... as i see it the script is good but it just won't save the xml to the file.... i don't get any error messages though.

i think that maybe the problem is that i don't give the exact path to the file.. can that be?

how do i get the path of the directory where the script runs?
something like the Server.MapPath in asp.

i guess that this is about it....
i'd love to get any ideas of why this does not work and how to make it work.
thanks!

Weedpacket

Originally posted by nitm
i'm new here and new with php so sorry for that...

Is not a problem; just giving you a heads-up early so that you don't accidentally annoy people in the future (me, I'm a grumpy old codger who gets annoyed by the sun coming up every single morning).

let's start with the php itself, i don't know which version of php i'm using because it's not on my computer.. i'm doing this script for a friend and i'm doing everything on his server (host: media temple).

There's a function, [man]phpversion[/man] that will supply this. I ran your code on a couple of different versions (5.0.3 and 4.3.10) and it worked in 4.3.10, but not in 5.0.3 (I had a look in bugs.php.net, and there may be a bug involved, though I'm not sure. But if you are using PHP 5.something, the DOM-XML extension is deprecated in favour if PHP5's inbuilt [man]DOM[/man] library instead).

i want to use only the xml dom functions and well, that is installed for sure because i don't get any error messages.

When I ran your code in 5.0.3., I got error messages that culminated in a Fatal Error. Your host may have turned off error display (if this is a live site, display_errors should be turned off), and the error messages are being logged somewhere instead. Put an extra command

ini_set('display_errors','1');

at the start of your code, just to see.

i know that the script opens the existing xml file with the parser, the problem is the saving part...
i've been sitting on the docs all nite to understand what's wrong, i didn't find it... as i see it the script is good but it just won't save the xml to the file.... i don't get any error messages though.

Did you try dumping it to the screen (using dump_mem to instead of dump_file to put it in a variableand then printing the contents of the variable)? Because of all the tags, you'd probably want to view the resulting source directly, because of couse an HTML renderer ignores tags it doesn't recognise. My test blah.xml read

<blah><foo>pink</foo></blah>

and the output in 4.3.10 was

<?xml version="1.0"?>
<blah>
  <foo>pink</foo>
</blah>
<entry id="1"/>

which I have to point out isn't valid XML (I think you want the entry element to be inside the root element).

i think that maybe the problem is that i don't give the exact path to the file.. can that be?

Unless your error display is turned off (see above) you'd get an error message about the file not being found. To find out where PHP looks for files, use [man]ini_get/man; (and while we're on the subject, a whole pile more diagnostic information can be fetched all at once with [man]phpinfo[/man].

how do i get the path of the directory where the script runs?
something like the Server.MapPath in asp.

All these and more are in the $SERVER array: $SERVER['SCRIPT_FILENAME'] is probably what you're after (it's been years since I touched ASP or VBScript).

nitm

thank you Weedpacket for your detailed reply.

the php version on the server is: 4.3.10.

i added the ini_set('display_errors','1'); line to my code and i still did not get any errors.

i used the dump_mem function and like you said, i got this:

<?xml version="1.0" encoding="windows-1255"?> <entries> </entries> <entry id="1"/>

can it be that it will not dump to the file because the new node is out-side of the root (document_element)?

how can i insert the new node inside the root?
i saw a function called insert_befor or something like that but if there are no nodes what should i do?

thanks

Weedpacket

Originally posted by nitm
can it be that it will not dump to the file because the new node is out-side of the root (document_element)?

No, that wouldn't be it; by then the XML has already been created, so there shouldn't be any trouble saving it in a file; the file should contain exactly what was in the string (which means that, if necessary, you could take that string and save it yourself). Since the file you're dumping into is the same as the one you're reading from, the dumped file should overwrite the original. So I'm not sure why you'd have a problem with this. Maybe it's write-protected or PHP doesn't have permission to write in that file? You'll note that the dump_file() method returns the number of bytes written - is this number correct?

how can i insert the new node inside the root?

You want the element to be a child of the root element, not a child of the entire document; so it's $root->append_child not $dom->append_child. (Notice that at present you're not actually using $root at all.)

nitm

thank you very much Weedpacket!
you were right, the permission to write had to be changed.
i'm sorry, i thought that it was already set because that's what my friend told me (and he owns the hosting space) but he was wrong.

also, i changed it so that the append_child will be on the $root and now the new node goes where it should, once again thanks.

a few more questions though:
(1) when i do this:

echo $root->has_child_nodes();

it prints 1 even if there are no nodes in the root. why is that?

(2) as i understand it the docs are @ http://www.php.net/manual/en/
now, in those docs it said that has_child_nodes() returns a boolean and not an integer, why is that?

(3) is there are a way to dump the xml string to the file in a way that the xml will look good? i mean with indentation and new lines and all?

thanks!