RSS newsfeed tutorial

To provide your users with RSS newsfeeds on your website just follow the steps described below. Good luck and happy coding! ;-)

--Andyknownasabu 19:08, 8 February 2008 (CST)

(1) Edit "protected/application.xml" and add a new entry in the services section. Two provide two different feeds on "products" and "services":

<service id="feed" class="System.Web.Services.TFeedService">
	<feed id="products" class="Application.common.FeedProvider" />
	<feed id="services" class="Application.common.FeedProvider" />
</service>

(2) Create a file "FeedProvider.php" in the directory "protected/common" as just defined in "application.xml":

<?php
/**
 * FeedProvider.php
 *
 * Copyright 2008 by Andreas Bulling
 * All rights reserved.
 * 
 * Terms of use and modification:
 * 
 * You may modify the following source code as you receive it, in any medium,
 * provided that you conspicuously and appropriately retain the above
 * original copyright notice.
 * 
 */
 
class FeedProvider implements IFeedContentProvider {
 
	private $_type;
 
	public function init($config) {
		$request = Prado::getApplication()->getRequest();
 
		if ($request->contains('feed')) {
			$this->_type = TPropertyValue::ensureString($request['feed']);
		}
	}
 
	public function getContentType() {
		return 'application/rss+xml';
	}
 
	public function getFeedContent() {
		$xmlString = '';
 
		// load content
		switch( $this->_type ) {
			case 'products':
				$records = ...
			break;
 
			case 'services':
				$records = ...
			break;
		}
 
		// generate RSS feed string
		$feed = new TXmlDocument('1.0', 'UTF-8');
		$feed->setTagName('rss');
		$feed->setAttribute('version', '2.0');
 
		$channel = new TXmlElement('channel');
		$feed->getElements()->insertAt(0, $channel);
 
		$channelTitle = new TXmlElement('title');
		$channelTitle->setValue('CHANNEL_TITLE');
		$channel->getElements()->insertAt(0, $channelTitle);
 
		$channelLink = new TXmlElement('link');
		$channelLink->setValue('http://foo.bar/index.php?feed=' . $this->_type);
		$channel->getElements()->insertAt(1, $channelLink);
 
		$channelDescription = new TXmlElement('description');
		$channelDescription->setValue('CHANNEL_DESCRIPTION');
		$channel->getElements()->insertAt(2, $channelDescription);
 
		$channelLanguage = new TXmlElement('language');
		$channelLanguage->setValue( Prado::getApplication()->getGlobalization()->getCulture() );
		$channel->getElements()->insertAt(3, $channelLanguage);
 
		$channelCopyright = new TXmlElement('copyright');
		$channelCopyright->setValue('CHANNEL_COPYRIGHT');
		$channel->getElements()->insertAt(4, $channelCopyright);
 
		$channelLastBuildDate = new TXmlElement('lastBuildDate');
		$channelLastBuildDate->setValue(date('r'));
		$channel->getElements()->insertAt(5, $channelLastBuildDate);
 
		$channelGenerator = new TXmlElement('generator');
		$channelGenerator->setValue('CHANNEL_GENERATOR');
		$channel->getElements()->insertAt(6, $channelGenerator);
 
		$channelWebmaster = new TXmlElement('webMaster');
		$channelWebmaster->setValue('CHANNEL_WEBMASTER');
		$channel->getElements()->insertAt(7, $channelWebmaster);
 
		$channelImage = new TXmlElement('image');
		$channel->getElements()->insertAt(8, $channelImage);
 
		$channelImageURL = new TXmlElement('url');
		$channelImageURL->setValue('http://foo.bar/logo.gif');
		$channelImage->getElements()->insertAt(0, $channelImageURL);
 
		$channelImageTitle = new TXmlElement('title');
		$channelImageTitle->setValue('CHANNEL_TITLE');
		$channelImage->getElements()->insertAt(1, $channelImageTitle);
 
		$channelImageLink = new TXmlElement('link');
		$channelImageLink->setValue('CHANNEL_LINK');
		$channelImage->getElements()->insertAt(2, $channelImageLink);
 
		foreach( $records as $record ) {
			$i = 0;
			$channelItems = new TXmlElement('item');
 
			$itemTitle = new TXmlElement('title');
			$title = utf8_encode($record->title);
			$itemTitle->setValue($title);
			$channelItems->getElements()->insertAt($i++, $itemTitle);
 
			$itemLink = new TXmlElement('link');
			$itemLink->setValue('ITEM_LINK');
			$channelItems->getElements()->insertAt($i++, $itemLink);
 
			$itemDesc = new TXmlElement('description');
			$description = utf8_encode($record->description);
			$itemDesc->setValue($description);
			$channelItems->getElements()->insertAt($i++, $itemDesc);
 
			$itemAuthor = new TXmlElement('author');
			$itemAuthor->setValue('ITEM_AUTHOR');
			$channelItems->getElements()->insertAt($i++, $itemAuthor);
 
			$itemPubDate = new TXmlElement('pubDate');
			$itemPubDate->setValue( date('r', $record->added_at) );
			$channelItems->getElements()->insertAt($i++, $itemPubDate);
 
			$channel->getElements()->insertAt(9, $channelItems);
		}
 
		// return RSS news feed string
		return $feed->saveToString();
	}
}
 
?>

(3) Access your feeds by pointing your browser to one of the following URLs:

http://foo.bar/index.php?feed=products

http://foo.bar/index.php?feed=services

(4) Finally, you should also add the following lines inside the <head> section of your main template which makes browsers show a nice icon indicating that your website provides RSS newsfeeds:

<head>
...
<link rel="alternate" type="application/rss+xml" title="Products" href="http://foo.bar/index.php?feed=products" />
<link rel="alternate" type="application/rss+xml" title="Services" href="http://foo.bar/index.php?feed=services" />
...
</head>