A quick PHP XMLWriter Class Tutorial (XML & RSS)

iceomnia · 07-10-2008, 07:46 AM

Since there is absolutely no documentation on how to use PHP5's XMLWriter class, here is a very simple example of how to use the class to create an rss feed.

PHP Code:


			
<?php



// THIS IS ABSOLUTELY ESSENTIAL - DO NOT FORGET TO SET THIS

@date_default_timezone_set("GMT");



$writer = new XMLWriter();

// Output directly to the user



$writer->openURI('php://output');

$writer->startDocument('1.0');



$writer->setIndent(4);



// declare it as an rss document

$writer->startElement('rss');

$writer->writeAttribute('version', '2.0');

$writer->writeAttribute('xmlns:atom', 'http://www.w3.org/2005/Atom');





$writer->startElement("channel");

//----------------------------------------------------

//$writer->writeElement('ttl', '0');

$writer->writeElement('title', 'Latest Products');

$writer->writeElement('description', 'This is the latest products from our website.');

$writer->writeElement('link', 'http://www.domain.com/link.htm');

$writer->writeElement('pubDate', date("D, d M Y H:i:s e"));

    $writer->startElement('image');

        $writer->writeElement('title', 'Latest Products');

        $writer->writeElement('link', 'http://www.domain.com/link.htm');

        $writer->writeElement('url', 'http://www.iab.net/media/image/120x60.gif');

        $writer->writeElement('width', '120');

        $writer->writeElement('height', '60');

    $writer->endElement();

//----------------------------------------------------







//----------------------------------------------------

$writer->startElement("item");

$writer->writeElement('title', 'New Product 8');

$writer->writeElement('link', 'http://www.domain.com/link.htm');

$writer->writeElement('description', 'Description 8 Yeah!');

$writer->writeElement('guid', 'http://www.domain.com/link.htm?tiem=1234');



$writer->writeElement('pubDate', date("D, d M Y H:i:s e"));



$writer->startElement('category');

    $writer->writeAttribute('domain', 'http://www.domain.com/link.htm');

    $writer->text('May 2008');

$writer->endElement(); // Category



// End Item

$writer->endElement();

//----------------------------------------------------





// End channel

$writer->endElement();



// End rss

$writer->endElement();



$writer->endDocument();



$writer->flush();

?>

The above will give you this:

Code:

<?xml version="1.0"?> 
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"> 
<channel> 
 <title>Latest Products</title> 
 <description>This is the latest products from our website.</description> 
 <link>http://www.domain.com/link.htm</link> 
 <pubDate>Thu, 10 Jul 2008 11:47:14 GMT</pubDate> 
 <image> 
  <title>Latest Products</title> 
  <link>http://www.domain.com/link.htm</link> 
  <url>http://www.iab.net/media/image/120x60.gif</url> 
  <width>120</width> 
  <height>60</height> 
 </image> 
 <item> 
  <title>New Product 8</title> 
  <link>http://www.domain.com/link.htm</link> 
  <description>Description 8 Yeah!</description> 
  <guid>http://www.domain.com/link.htm?tiem=1234</guid> 
  <pubDate>Thu, 10 Jul 2008 11:47:14 GMT</pubDate> 
  <category domain="http://www.domain.com/link.htm">May 2008</category> 
 </item> 
</channel> 
</rss>

Just a note from an rss validator, this line should be before the 'channel' tag for some reason!

Code:

<atom:link href="http://dallas.example.com/rss.xml" rel="self" type="application/rss+xml" />

I will post another example below for the php5 XMLReader Class later.

iceomnia · 07-10-2008, 08:33 AM

...and here's how to use it as a pre made class...

PHP Code:


			
@date_default_timezone_set("GMT");





class rss extends XMLWriter

{

    // $file = filename to output to

    // $title = rss fed title

    // $description = rss feed description

    // $link = rss feed link

    // $date = date of feed

    

    function __construct($file, $title, $description, $link, $date)

    {

        // Start by calling the XMLWriter constructor...

        

        $this->openURI($file);

        $this->startDocument('1.0');

        $this->setIndent(4);

        

        $this->startElement('rss');

            $this->writeAttribute('version', '2.0');

            $this->writeAttribute('xmlns:atom', 'http://www.w3.org/2005/Atom');



        $this->startElement("channel");

            $this->writeElement('title', $title);

            $this->writeElement('description', $description);

            $this->writeElement('link', $link);

            $this->writeElement('pubDate', date("D, d M Y H:i:s e", strtotime($date)));

        

    }

    

    // Send a multi-dimensional array

    // $array = 

    // 'title' = Item title

    // 'descritpion'

    // 'link'

    // 'guid' = unique id for item (should be a url)

    

    // 'category' = array of:

    // 'title'

    // 'domain'

    

    function addItem($array)

    {

        if (is_array($array))

        {

            $this->startElement("item");

            $this->writeElement('title', $array['title']);

            $this->writeElement('link', $array['link']);

            $this->writeElement('description', $array['description']);

            $this->writeElement('guid', $array['guid']);

            

            if (isset($array['date']))

            {

                $this->writeElement('pubDate', date("D, d M Y H:i:s e", strtotime($array['date'])));

            }

            

            if (isset($array['category']) && isset($array['category']['title']))

            {

                $this->startElement('category');

                    $this->writeAttribute('domain', $array['category']['domain']);

                    $this->text($array['category']['title']);

                $this->endElement(); // Category

            }

        $this->endElement(); // Item

        }

        

    }

    

    function _endRss()

    {

        // End channel

        $this->endElement();

        

        // End rss

        $this->endElement();

        

        $this->endDocument();

        

        $this->flush();

    }

    

} // end class...

...and a sample on the class usage!

PHP Code:


			
// Sample usage of class...



$item = array();

$item['title'] = 'New product One';

$item['link'] = 'http://www.domain.com/product1.htm';

$item['description'] = 'A full description of product that is new.';

$item['guid'] = 'http://www.domain.com/product1.htm'; // a unique http address will do!

$item['date'] = date('Y-m-d'); //send any time of date!



$item['category'] = array();

$item['category']['title'] = 'CD Players';

$item['category']['domain'] = 'http://www.domain.com/cdplayers.htm';



$w = new rss('php://output', 'New Products', 'This month\'s new products', 'http://www.domain.com/link.htm', date('Y-m-d'));

    

$w->addItem($item);



$w->_endRss();

You could use a destructor, but I think the '_endRss' is better.

Next project... PHP XMLReader

iceomnia · 02-17-2009, 06:14 PM

I'm just writing an extension to XMLReader - this will give you a good example of how to manipulate an RSS XML news feed for your website...

I'll post a link here when it's ready...

__________________

Web Design <- PHP Website Design & Programming

tekneck · 12-04-2009, 07:17 PM

In the example below (btw, thanks so much for this class and the details!), how would I make a looping section.

I want to include a bunch of images in each $item and keep overwriting the variables...

ie:

<item>
<title>Title</title>
<link>link url</link>
<images>
<image>
<title>image title</title>
<url>imageurl</ul>
</image>
<image>
<title>image title</title>
<url>imageurl</ul>
</image>
<image>
<title>image title</title>
<url>imageurl</ul>
</image>
</images>
</item>

When I use the code below and the class, I only get one image (the last one from my while sql query results)

When I make the array key->values unique by adding a counter (eg: key1->value1,key2->value2 etc) I get all my images under one <image>array data</image> instead of multiple <image>stuff from first record</image><image>stuff from second record</image> etc...

Here is what I have done... perhaps you can help me with this concept.. I am not sure if XMLWriter supports what I am trying to do...

PHP Code:


			


if (isset($array['images']))

            {

                $this->startElement('media');

                    

                        $this->startElement('image');

                        

                        foreach ($array['images'] as $key => $value)

                        { 

                            $this->writeElement($key, $value);

                        }

                        $this->endElement();

                

                

                $this->endElement(); 

            }

And to set the array in my code I am doing:

PHP Code:


			


if(mysql_num_rows($images))

        {

            $item['images'] = array();

            $image_count = 1;

            

            while($image_row = mysql_fetch_assoc($images)) 

            

            {

                $item['images']['image_'.$image_count.'_seq'] = $image_row['display_order'];

                $item['images']['image_'.$image_count.'_filename'] = $image_row['full_filename'];

                $image_count ++;

            }

        }

So I am close to what I needed but not all the way...

Ideas, gurus?