silverstripe-framework/docs/en/02_Developer_Guides/11_Integration/02_RSSFeed.md
Aaron Carlino 6888901468
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RSS Feed Output records from your database as an RSS Feed. rss

RSS Feed

Generating RSS / Atom-feeds is a matter of rendering a SS_List instance through the RSSFeed class.

The 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 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 it's advisable to just create feeds from subclasses of SiteTree.

[warning] If you wish to generate an RSS feed that contains a DataObject, ensure you define a AbsoluteLink method on the object. [/warning]

Usage

Including an RSS feed has two steps. First, a Controller action which responses with the XML and secondly, the other web pages need to link to the URL to notify users that the RSS feed is available and where it is.

An outline of step one looks like:

use SilverStripe\Control\RSS\RSSFeed;

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

$feed->outputToBrowser();

To achieve step two include the following code where ever you want to include the <link> tag to the RSS Feed. This will normally go in your Controllers init method.

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

Examples

Showing the 10 most recently updated pages

You can use RSSFeed to easily create a feed showing your latest Page updates. The following example adds a page /home/rss/ which displays an XML file the latest updated pages.

app/code/PageController.php

use SilverStripe\Control\RSS\RSSFeed;
use SilverStripe\CMS\Controllers\ContentController;

class PageController extends ContentController 
{
    private static $allowed_actions = [
        'rss'
    ];

    public function init() 
    {
        parent::init();

        RSSFeed::linkToFeed($this->Link("rss"), "10 Most Recently Updated Pages");
    }

    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 SiteTree subclasses we need to include a function AbsoluteLink to allow the RSS feed to link through to the item.

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

Take an example, we want to create an RSS feed of all the Players objects in our site. We make sure the AbsoluteLink method is defined and returns a string to the full website URL.

use SilverStripe\Control\Controller;
use SilverStripe\Control\Director;
use SilverStripe\ORM\DataObject;

class Player extends DataObject 
{

    public function AbsoluteLink() 
    {
        // assumes players can be accessed at yoursite.com/players/2

        return Controller::join_links(
            Director::absoluteBaseUrl(),
            'players',
            $this->ID
        );
    }
}

Then in our controller, we add a new action which returns a the XML list of Players.

use SilverStripe\Control\RSS\RSSFeed;
use SilverStripe\CMS\Controllers\ContentController;

class PageController extends ContentController 
{

    private static $allowed_actions = [
        'players'
    ];

    public function init() 
    {
        parent::init();

        RSSFeed::linkToFeed($this->Link("players"), "Players");
    }

    public function players() 
    {
        $rss = new RSSFeed(
            Player::get(),
            $this->Link("players"),
            "Players"
        );

        return $rss->outputToBrowser();
    }
}

Customizing the RSS Feed template

The default template used for XML view is vendor/silverstripe/framework/templates/RSSFeed.ss. This template displays titles and links to the object. To customise the XML produced use setTemplate.

Say from that last example we want to include the Players Team in the XML feed we might create the following XML file.

app/templates/PlayersRss.ss

<?xml version="1.0"?>
<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom">
    <channel>
        <title>$Title</title>
        <link>$Link</link>
        <atom:link href="$Link" rel="self" type="application/rss+xml" />
        <description>$Description.XML</description>

        <% loop $Entries %>
        <item>
            <title>$Title.XML</title>
            <team>$Team.Title</team>
        </item>
        <% end_loop %>
    </channel>
</rss>

setTemplate can then be used to tell RSSFeed to use that new template.

app/code/Page.php

use SilverStripe\Control\RSS\RSSFeed;

public function players() 
{
    $rss = new RSSFeed(
        Player::get(),
        $this->Link("players"),
        "Players"
    );

    $rss->setTemplate('PlayersRss');

    return $rss->outputToBrowser();
}

[warning] As we've added a new template (PlayersRss.ss) make sure you clear your SilverStripe cache. [/warning]

API Documentation