XML(RSS) and PHP?

Morbius

I'm no noob to PHP but this XML stuff is all new to me.

From what I understand I need some kind of Parser to read the XML doc.

In the case of an RSS feed I need to know how to get my MySQL data into the XML RSS feed.

My first instinct was to just make an rss.php file and integrate my PHP as a while loop for all the xml item tags I need.

Does that make sense... yeah, I'm confused too.

Any help would be great.

planetsim

Creating an RSS feed with PHP is quite easy. Basically you have the right idea of looping each item tag. However you will still need to XML declaration and the rss tags and information tags such as title etc.

However you will require a parser to read these. You should read up on XML first to get a better idea as XML is quite strict some characters arent allowed.

Morbius

But as I'm understanding it the XML won't work in a .php file. So if that's correct then I need to somehow get my PHP data into a .xml file. Or am I way off base?

Weedpacket

An XML parser would be for if you had an XML file and you wanted to extract information from it. It's not needed for generating XML, because XML is just text like any other text file. PHP can write XML quite happily. The only elaboration is that before you write the XML document you should add a header that states that the document to follow is XML so that the client knows what to do with it. Otherwise the process is exactly the same as for (X)HTML - only the names of the tags are different.

Morbius

Ok, I tried that actually. I was looking at RSS code from other sites in FireFox and I noticed the header is something like

<?xml version="1.0" encoding="iso-8859-1"?>

But the <? looks like PHP code to my server. So it breaks. What should the header be? Maybe this is the answer to my problem.

bpat1434

From what i understand....

<?xml ?> is just a declaration that belongs at the very top of your XML file. This tells the server that it's dealing with an xml file. It won't look at it and see php because there is no php after the <?.

This might help you out....
http://searchenginewatch.com/sereport/article.php/2175271#Resources

Morbius

But how can you put <? into PHP without it thinking it's PHP? I tried to echo it and that didnt' seem to work. Guess I'll play with it more.

bpat1434

A standard xml document looks as follows:

<?xml version="1.0" encoding="iso-8859-1"?>
<!-- Tags of all sorts -->

Now, an rss feed looks like:

<?xml version="1.0" encoding="iso-8859-1"?>
<rss version="0.9.1">
  <channel>
    <item>
      <title>Something</title>
      <link>[url]http://www.url.com[/url]</link>
      <description>Some description about the site</description>
    </item>
  </channel>
</rss>

So how is it so hard to use php to write that?

<?php
echo '<?xml version="1.0" encoding="iso-8859-1"?>'.
    '<rss version="0.9.1">'.
    '<channel>';
while($display = mysql_fetch_array($result)){
        echo '<item>'.
            '<title>'.$display['Title'].'</title>'.
            '<link>'.$display['Link'].'</link>'.
            '<description>'.$display['Description'].'</description>'.
            '</item>';
}
echo '</channel>'.
        '</rss>';

The more appropriate way would be to create an empty xml document, upload it to your server, and then fopen() and write to that file using the same guidelines as above.

~Brett

Morbius

I'll give that shot. Thanks.

Tivolicious

Arrghhhh. I'm having the exact same problem. Unfortunately, I can't just write to a file because the PHP page takes arguments.

e.g.

/script.php?foo=bar

I can't seem to get the darn <? for the xml in there.

bpat1434

Create a variable called: $open and $close. Then echo them:

$open = '<?';
$close = '?>';

They won't be looked upon as "php" tags, but just a string of characters.

~Brett

Weedpacket

If you have enough control over the server (i.e., you can edit php.ini, .htaccess, or httpd.conf), turn short_open_tag off, and then <? will only be interpreted as opening a PHP block if it is the start of <?php