test1/public/drupal-8.3.1/vendor/zendframework/zend-feed/doc/book/consuming-rs...

Consuming RSS Feeds

Reading a feed

To read an RSS feed, pass its URL to Zend\Feed\Reader\Reader::import():

$channel = Zend\Feed\Reader\Reader::import('http://rss.example.com/channelName');

Importing requires an HTTP client

To import a feed, you will need to have an HTTP client available.

If you are not using zend-http, you will need to inject Reader with the HTTP client. See the section on providing a client to Reader.

If any errors occur fetching the feed, a Zend\Feed\Reader\Exception\RuntimeException will be thrown.

Get properties

Once you have a feed object, you can access any of the standard RSS channel properties via the various instance getter methods:

echo $channel->getTitle();
echo $channel->getAuthor();
// etc.

If channel properties have attributes, the getter method will return a key/value pair, where the key is the attribute name, and the value is the attribute value.

$author = $channel->getAuthor();
echo $author['name'];

Most commonly, you'll want to loop through the feed and do something with its entries. Zend\Feed\Reader\Feed\Rss internally converts all entries to a Zend\Feed\Reader\Entry\Rss instance. Entry properties, similarly to channel properties, can be accessed via getter methods, such as getTitle, getDescription, etc.

An example of printing all titles of articles in a channel is:

foreach ($channel as $item) {
    echo $item->getTitle() . "\n";
}

If you are not familiar with RSS, here are the standard elements you can expect to be available in an RSS channel and in individual RSS items (entries).

Required channel elements:

• title: The name of the channel.
• link: The URL of the web site corresponding to the channel.
• description: A sentence (or more) describing the channel.

Common optional channel elements:

• pubDate: The publication date of this set of content, in RFC 822 date format.
• language: The language the channel is written in.
• category: One or more (specified by multiple tags) categories the channel belongs to.

RSS <item> elements do not have any strictly required elements. However, either title or description must be present.

Common item elements:

• title: The title of the item.
• link: The URL of the item.
• description: A synopsis of the item.
• author: The author's email address.
• category: One more categories that the item belongs to.
• comments: URL of comments relating to this item.
• pubDate: The date the item was published, in RFC 822 date format.

In your code you can always test to see if an element is non-empty by calling the getter:

if ($item->getPropname()) {
    // ... proceed.
}

Where relevant, Zend\Feed supports a number of common RSS extensions including Dublin Core, Atom (inside RSS); the Content, Slash, Syndication, Syndication/Thread extensions; as well as several others.

Please see the official RSS 2.0 specification for further information.