PHP and AJAX *head desk*

So, Thursday afternoon I broke my brain for the weekend trying to figure out why the heck a script that is working perfectly well on one server isn't working right on another server. Day one was wasted trying to figure out HOW to figure out what the heck was going on. The logs told me nothing. The page itself was not giving any hints. Since the whole thing was happening in AJAX land, behind the scenes and without giving any useful output to the browser, I couldn't use debugging tricks like echo and print_r to figure out what was going on with my variables. This morning, however, my brain was in better gear than it was Thursday afternoon, so I started the day off by actually doing something useful.

When you need a script to give you useful information in the browser, and the page in question is using AJAX to send information (but not, at the moment, receive information), then (DUH!) use AJAX to give you the information you need!!!

In my case I had a handy editor box in which to plunk the response text from the AJAX request.

xmlhttp.onreadystatechange = function(){
if (xmlhttp.readyState == 4) {

document.forms["editorbox"].editorBox.value = xmlhttp.responseText;
}
}

At one point, I used alert(xmlhttp.responseText) instead of the editorbox, but that wasn't as useful because the alert box doesn't let you select and copy stuff if you need it. Also, my editorbox had a handy-dandy scroll bar, and the errors coming out of my responseText were numerous.

In order to make the responseText useful, you may want to echo out certain variables and then exit; so that the info you want -- and only the info you want -- will show up where you need it.

Now, as to what was actually wrong with the script I was messing with today... It appears that a difference in php.ini files was my problem. In the version of the script that was NOT working, all the quotes were getting escaped as they got soaked up into the PHP script. When I then tried to dom->loadXML($myXML) the script was complaining that my XML was no good. Well, of course it's no good, there's all these darned escape characters before the quotes!

I don't want to change the php.ini on the server, so I have to get rid of those escapes some other way. preg_replace to the rescue!


$pat = '/\\\"/';
$rep = "'";
$myXML = preg_replace($pat, $rep, $myXML);


All better. :)

Having Trouble Importing Drupal Translation Packs?

OMG I just spent way too long pulling my hair out over the Drupal 6 translation import feature. To put it simply, the handbook and help information is very UNCLEAR about what you are supposed to do.

The instructions say to download the translation pack into your install directory and unzip it. So, if, like me, you don't have access to the server that will allow you to unzip a folder on the server, logic says that you should be able to unzip the folder on your own machine and simply ftp the folder into place, right? Wrong. Well, at least sort of wrong.

Let's say you have the he-6.x-1.0 translation pack. You've unzipped it, and now it's sitting on your PC's desktop. You want to move it to your server. DO NOT copy that whole folder over to the server so that you end up with something like /webroot/drupal/he-6.x-10 on your server.

What you DO want to do is copy the CONTENTS of he-6.x-10 over onto the server so that the internal directory structures plop into place inside the existing directory structure in drupal. That way you will have something like /webroot/drupal/modules/aggregator/translations/modules-aggregator.he.po and so forth.

As you can see here, each directory that has translations (modules, themes, etc. anything that has t() strings, really) gets it own translations directory and language po files go in there.

The easiest way to get all of those files to plonk into the right place is, in fact, to un-zip the file insitu at your server rather than trying to ftp the files over post-expansion.

Interesting tidbit about PHP objects

I'm doing some XML stuff right now, using SimpleXML in PHP. One of the element groups I need to create is a list of descriptions in different languages. My original attempt looked like this:

$descriptions = array(
'en' => 'An awsome app.',
'es' => 'Una aplicacion chevere.',
'he' => 'אפליקציה מעולה',
);

foreach($descriptions as $loc => $desc) {
$d->addChild('description', $desc);
$d->description->addAttribute('locale', $loc);
}
echo $xml_post->asXML();


But that gave me an error:

Warning: SimpleXMLElement::addAttribute() [function.SimpleXMLElement-addAttribute]: Attribute already exists in...

When I looked at the code, the attribute was only getting plunked into the first <description> tag. The PHP engine thought that each time I went through the loop I was talking about the same $d->description when I asked it to stick a locale attribute in there. Weird. I expected the object to be treated like any other variable and get treated as a fresh thing. Nope.

If you put

echo $d->description . "<br />"

after the addChild() above, you'll see that it echoes out

an awesome app.
an awesome app.

If, however you change that block of code to

foreach($descriptions as $loc => $desc) {
$tag = $d->addChild('description', $desc);
echo $tag . "<br />";
}

you'll see that $tag prints out the correct description line for that pass through the loop:

An awsome app.
Una aplicacion chevere.
אפליקציה מעולה

So, the correct code to create the XML I want is

$descriptions = array(
'en' => 'An awsome app.',
'es' => 'Una aplicacion chevere.',
'he' => 'אפליקציה מעולה',
);
foreach($descriptions as $loc => $desc) {
$tag = $d->addChild('description', $desc);
$tag->addAttribute('locale', $loc);
}
echo $xml_post->asXML();


And then the XML comes out right.

<description locale="en">An awsome app.</description>
<description locale="es">Una aplicacion chevere.</description>
<description locale="he">אפליקציהמעולה</description>


Internationalization/Localization Cheat Sheet

ISO 639-2 Language Codes live here:
http://www.loc.gov/standards/iso639-2/php/code_list.php

Command Line Tools
xgettext will collect all your strings for you from a file or set of files into a po file.

msgfmt will turn your po files into mo files.


info gettext will get you all the info you need to use the GNU gettext utility.


File Structure
Stick your po and mo files into a structure like this:

/src
   /locale/en/LC_MESSAGES/messages.mo
                          messages.po
           es/LC_MESSAGES/messages.po
                          messages.mo 

PHP Functions
putenv ("LC_ALL=es"); sets your locale to Spanish.
bindtextdomain ("messages", "./locale"); shows where to find the translation tables.
textdomain ("messages"); says what domain we're using.

Internationalize your strings in PHP using the handy-dandy underscore operator.
print(_("Hello World"));

More info on gettext functions in PHP:
http://php.net/gettext