rss-bridge/docs/05_Bridge_API/03_FeedExpander.md

3.7 KiB

FeedExpander extends BridgeAbstract and adds functions to collect data from existing feeds.

Usage example: You have discovered a site that provides feeds which are hidden and inaccessible by normal means. You want your bridge to directly read the feeds and provide them via RSS-Bridge

To create a new Bridge extending FeedExpander you must implement all required functions of BridgeAbstract. FeedExpander additionally provides following functions:

Find a template at the end of this file.

Notice: For a standard feed only collectData need to be implemented. collectData should call $this->collectExpandableDatas('your URI here'); to automatically load feed items and header data (will subsequently call parseItem for each item in the feed). You can limit the number of items to fetch by specifying an additional parameter for: $this->collectExpandableDatas('your URI here', 10) (limited to 10 items).

The parseItem function

This function receives one item from the current feed and should return one RSS-Bridge item. The default function does all the work to get the item data from the feed, whether it is RSS 1.0, RSS 2.0 or Atom 1.0. If you have to redefine this function in your RSS-Bridge for whatever reason, you should first call the parent function to initialize the item, then apply the changes that you require.

Notice: The following code sample is just an example. Implementation depends on your requirements!

protected function parseItem($feedItem){
    $item = parent::parseItem($feedItem);
    $item['content'] = str_replace('rssbridge','RSS-Bridge',$feedItem->content);

    return $item;
}

Helper functions

The FeedExpander already provides a set of functions to parse RSS or Atom items based on the specifications. Where possible make use of these functions:

Function Description
parseATOMItem Parses an Atom 1.0 feed item
parseRSS_0_9_1_Item Parses an RSS 0.91 feed item
parseRSS_1_0_Item Parses an RSS 1.0 feed item
parseRSS_2_0_Item Parses an RSS 2.0 feed item

In the following list you'll find the feed tags assigned to the the RSS-Bridge item keys:

Function uri title timestamp author content
parseATOMItem id title updated author content
parseRSS_0_9_1_Item link title description
parseRSS_1_0_Item link title dc:date dc:creator description
parseRSS_2_0_Item link, guid title pubDate, dc:date author, dc:creator description

The getName function

Returns the name of the current feed.

return $this->name;

Notice: Only implement this function if you require different behavior!

The getURI function

Return the uri for the current feed.

return $this->uri;

Notice: Only implement this function if you require different behavior!

The getDescription function

Returns the description for the current bridge.

return $this->description;

Notice: Only implement this function if you require different behavior!

Template

This is the template for a new bridge:

<?php
class MySiteBridge extends FeedExpander {

	const MAINTAINER = 'No maintainer';
	const NAME = 'Unnamed bridge';
	const URI = '';
	const DESCRIPTION = 'No description provided';
	const PARAMETERS = array();
	const CACHE_TIMEOUT = 3600;

    public function collectData(){
        $this->collectExpandableDatas('your feed URI');
    }
}
// Imaginary empty line!