silverstripe-framework/docs/en/reference/rssfeed.md
cieszak 092cda89af Update rssfeed.md
add $allowed_actions
2013-10-15 23:01:23 +02:00

5.4 KiB

RSS Feed

Introduction

Generating RSS/Atom-feeds is a matter of rendering a [api:SS_List] through the [api:RSSFeed] class.

The [api:RSSFeed] class doesn't limit you to generating article based feeds, it is just as easy to create a feed of your current staff members, comments or any other custom [api:DataObject] subclasses you have defined. The only logical limitation here is that every item in the RSS-feed should be accessible through a URL on your website, so its advisable to just create feeds from sub classes of [api:SiteTree].

If you wish to generate an RSS feed for [api:DataObject] instances, ensure they define an AbsoluteLink() method.

Usage

:::php
RSSFeed::linkToFeed($link, $title)

This line should go in your [api:Controller] subclass in the action you want to include the HTML link.

:::php
$feed = new RSSFeed(
	$list, 
	$link, 
	$title, 
	$description, 
	$titleField, 
	$descriptionField, 
	$authorField
);

Creates a new [api:RSSFeed] instance to be returned. The arguments notify SilverStripe what values to include in the feed.

Examples

Showing latest blog posts

:::php
class Page_Controller extends ContentController {
	private static $allowed_actions = array('rss');
	public function init() {
		// linkToFeed will add an appropriate HTML link tag to the website 
		// <head> tag to notify web browsers that an RSS feed is available 
		// for this page. You can include as many feeds on the page as you 
		// wish as long as each as a different link. For example: 
		// ('blog/rss', 'staff/rss').
		// 
		// In this example $this->Link("rss") refers to the *rss* function
		// we define below.
		RSSFeed::linkToFeed($this->Link("rss"), "RSS feed of this blog");
		parent::init();
	}
	public function rss() {
		// Creates a new RSS Feed list
		$rss = new RSSFeed(
			$list = $this->getBlogPosts(), // an SS_List containing your feed items
			$link = $this->Link("rss"), // a HTTP link to this feed
			$title = "My feed", // title for this feed, displayed in RSS readers
			$description = "This is an example feed." // description
		);
		// Outputs the RSS feed to the user.
		return $rss->outputToBrowser();
	}
	public function getBlogPosts() {
		return BlogPage::get()->limit(10);
	}
}

Showing the 10 most recently updated pages

You can use [api:RSSFeed] to easily create a feed showing your latest Page updates. Update mysite/code/Page.php to something like this:

:::php
<?php
class Page extends SiteTree {}	
class Page_Controller extends ContentController {

	private static $allowed_actions = array('rss');
	
	public function init() {
		RSSFeed::linkToFeed($this->Link() . "rss", "10 Most Recently Updated Pages");	
		parent::init();
	}
	
	public function rss() {
		$rss = new RSSFeed($this->LatestUpdates(), $this->Link(), "10 Most Recently Updated Pages", "Shows a list of the 10 most recently updated pages.");
		return $rss->outputToBrowser();
	}
	
	public function LatestUpdates() {
		return Page::get()->sort("LastEdited", "DESC")->limit(10);
	} 
}

Rendering DataObjects in a RSSFeed

DataObjects can be rendered in the feed as well, however, since they aren't explicitly [api:SiteTree] subclasses we need to include a function AbsoluteLink to allow the RSS feed to link through to the item.

If the items are all displayed on a single page you may simply hard code the link to point to a particular page.

Take an example, we want to create an RSS feed of all the Students, a DataObject we defined in the fifth tutorial.

:::php
<?php 
class Student extends DataObject {
	public function AbsoluteLink() {
		// see tutorial 5, students are assigned a project, so the 'link'
		// to view the student is based on their projects link.
		return $this->Project()->AbsoluteLink();
	}
}

Then update the Page_Controller class in mysite/code/Page.php to include an RSSFeed for all the students as we've seen before.

:::php
class Page_Controller extends ContentController {
	private static $allowed_actions = array('students');
	public function init() {
		RSSFeed::linkToFeed($this->Link("students"), "Students feed");
		parent::init();
	}		
	public function students() {
		$rss = new RSSFeed(
			$list = $this->getStudents(),
			$link = $this->Link("students"), 
			$title = "Students feed" 
		);
		return $rss->outputToBrowser();
	}
	public function getStudents() {
		return Student::get()->sort("Created", "DESC")->limit(10);
	}
}

Customizing the RSS Feed template

The default template used is framework/templates/RSSFeed.ss and includes displaying titles and links to the content. If you have a particular need for customizing the XML produced (say for additional meta data) use setTemplate.

Taking that last example, we would rewrite the students function to include a unique template (write your own XML in themes/yourtheme/templates/Students.ss)

:::php
public function students() {
	$rss = new RSSFeed(
		$list = $this->getStudents(),
		$link = $this->Link("students"), 
		$title = "Students feed" 
	);
	$rss->setTemplate('Students');
	return $rss->outputToBrowser();
}

External Sources

[api:RSSFeed] only creates feeds from your own data. We've included the SimplePie RSS-parser for accessing feeds from external sources.

API Documentation

  • [api:RSSFeed]