Question

fetch_feed( mixed $url )

Build SimplePie object based on RSS or Atom feed from URL.

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description

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参数

$url

(mixed) (Required) URL of feed to retrieve. If an array of URLs, the feeds are merged using SimplePie's multifeed feature. See also ​<a href="http://simplepie.org/wiki/faq/typical_multifeed_gotchas">http://simplepie.org/wiki/faq/typical_multifeed_gotchas</a>

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返回值

(WP_Error|SimplePie) WP_Error object on failure or SimplePie object on success

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源代码

File: wp-includes/feed.php

function fetch_feed( $url ) {
	if ( ! class_exists( 'SimplePie', false ) ) {
		require_once( ABSPATH . WPINC . '/class-simplepie.php' );
	}

	require_once( ABSPATH . WPINC . '/class-wp-feed-cache.php' );
	require_once( ABSPATH . WPINC . '/class-wp-feed-cache-transient.php' );
	require_once( ABSPATH . WPINC . '/class-wp-simplepie-file.php' );
	require_once( ABSPATH . WPINC . '/class-wp-simplepie-sanitize-kses.php' );

	$feed = new SimplePie();

	$feed->set_sanitize_class( 'WP_SimplePie_Sanitize_KSES' );
	// We must manually overwrite $feed->sanitize because SimplePie's
	// constructor sets it before we have a chance to set the sanitization class
	$feed->sanitize = new WP_SimplePie_Sanitize_KSES();

	$feed->set_cache_class( 'WP_Feed_Cache' );
	$feed->set_file_class( 'WP_SimplePie_File' );

	$feed->set_feed_url( $url );
	/** This filter is documented in wp-includes/class-wp-feed-cache-transient.php */
	$feed->set_cache_duration( apply_filters( 'wp_feed_cache_transient_lifetime', 12 * HOUR_IN_SECONDS, $url ) );
	/**
	 * Fires just before processing the SimplePie feed object.
	 *
	 * @since 3.0.0
	 *
	 * @param object &$feed SimplePie feed object, passed by reference.
	 * @param mixed  $url   URL of feed to retrieve. If an array of URLs, the feeds are merged.
	 */
	do_action_ref_array( 'wp_feed_options', array( &$feed, $url ) );
	$feed->init();
	$feed->set_output_encoding( get_option( 'blog_charset' ) );

	if ( $feed->error() )
		return new WP_Error( 'simplepie-error', $feed->error() );

	return $feed;
}

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更新日志

Version	description
2.8.0	Introduced.

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相关函数

Uses

• wp-includes/class-wp-feed-cache-transient.php: wp_feed_cache_transient_lifetime
• wp-includes/plugin.php: apply_filters()
• wp-includes/plugin.php: do_action_ref_array()
• wp-includes/feed.php: wp_feed_options
• wp-includes/option.php: get_option()
• wp-includes/class-wp-error.php: WP_Error::__construct()
Show 1 more use Hide more uses

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Used By

• wp-admin/includes/dashboard.php: wp_dashboard_rss_control()
• wp-admin/includes/deprecated.php: wp_dashboard_plugins_output()
• wp-includes/widgets/class-wp-widget-rss.php: WP_Widget_RSS::widget()
• wp-includes/widgets.php: wp_widget_rss_output()
• wp-includes/widgets.php: wp_widget_rss_process()

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User Contributed Notes

1. Skip to note content You must log in to vote on the helpfulness of this noteVote results for this note: 0You must log in to vote on the helpfulness of this note Contributed by Codex

   Example
   This example will retrieve and display a list of links for an existing RSS feed, limiting the selection to the five most recent items:

   
   <h2><?php _e( 'Recent news from Some-Other Blog:', 'wpdocs_textdomain' ); ?></h2>
   
   <?php // Get RSS Feed(s)
   include_once( ABSPATH . WPINC . '/feed.php' );
   
   // Get a SimplePie feed object from the specified feed 源代码.
   $rss = fetch_feed( 'http://example.com/rss/feed/goes/here' );
   
   $maxitems = 0;
   
   if ( ! is_wp_error( $rss ) ) : // Checks that the object is created correctly
   
   	// Figure out how many total items there are, but limit it to 5. 
   	$maxitems = $rss->get_item_quantity( 5 ); 
   
   	// Build an array of all the items, starting with element 0 (first element).
   	$rss_items = $rss->get_items( 0, $maxitems );
   
   endif;
   ?>
   
   <ul>
       <?php if ( $maxitems == 0 ) : ?>
           <li><?php _e( 'No items', 'wpdocs_textdomain' ); ?></li>
       <?php else : ?>
           <?php // Loop through each feed item and display each item as a hyperlink. ?>
           <?php foreach ( $rss_items as $item ) : ?>
               <li>
                   <a href="<?php echo esc_url( $item->get_permalink() ); ?>"
                       title="<?php printf( __( 'Posted %s', 'wpdocs_textdomain' ), $item->get_date('j F Y | g:i a') ); ?>">
                       <?php echo esc_html( $item->get_title() ); ?>
                   </a>
               </li>
           <?php endforeach; ?>
       <?php endif; ?>
   </ul>