WordPress at a glance
class is not described

WP_Widget_RSS{} WP 2.8.0

Core class used to implement a RSS widget.

Hooks in class
Return

Nothing (null).

Usage

$WP_Widget_RSS = new WP_Widget_RSS();
// use class methods

Methods

  1. __construct()
  2. widget( $args, $instance )
  3. update( $new_instance, $old_instance )
  4. form( $instance )

Code of WP Widget RSS: wp-includes/widgets/class-wp-widget-rss.php WP 5.2.2

<?php
class WP_Widget_RSS extends WP_Widget {

	/**
	 * Sets up a new RSS widget instance.
	 *
	 * @since 2.8.0
	 */
	public function __construct() {
		$widget_ops  = array(
			'description'                 => __( 'Entries from any RSS or Atom feed.' ),
			'customize_selective_refresh' => true,
		);
		$control_ops = array(
			'width'  => 400,
			'height' => 200,
		);
		parent::__construct( 'rss', __( 'RSS' ), $widget_ops, $control_ops );
	}

	/**
	 * Outputs the content for the current RSS widget instance.
	 *
	 * @since 2.8.0
	 *
	 * @param array $args     Display arguments including 'before_title', 'after_title',
	 *                        'before_widget', and 'after_widget'.
	 * @param array $instance Settings for the current RSS widget instance.
	 */
	public function widget( $args, $instance ) {
		if ( isset( $instance['error'] ) && $instance['error'] ) {
			return;
		}

		$url = ! empty( $instance['url'] ) ? $instance['url'] : '';
		while ( stristr( $url, 'http' ) != $url ) {
			$url = substr( $url, 1 );
		}

		if ( empty( $url ) ) {
			return;
		}

		// self-url destruction sequence
		if ( in_array( untrailingslashit( $url ), array( site_url(), home_url() ) ) ) {
			return;
		}

		$rss   = fetch_feed( $url );
		$title = $instance['title'];
		$desc  = '';
		$link  = '';

		if ( ! is_wp_error( $rss ) ) {
			$desc = esc_attr( strip_tags( @html_entity_decode( $rss->get_description(), ENT_QUOTES, get_option( 'blog_charset' ) ) ) );
			if ( empty( $title ) ) {
				$title = strip_tags( $rss->get_title() );
			}
			$link = strip_tags( $rss->get_permalink() );
			while ( stristr( $link, 'http' ) != $link ) {
				$link = substr( $link, 1 );
			}
		}

		if ( empty( $title ) ) {
			$title = ! empty( $desc ) ? $desc : __( 'Unknown Feed' );
		}

		/** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */
		$title = apply_filters( 'widget_title', $title, $instance, $this->id_base );

		$url  = strip_tags( $url );
		$icon = includes_url( 'images/rss.png' );
		if ( $title ) {
			$title = '<a class="rsswidget" href="' . esc_url( $url ) . '"><img class="rss-widget-icon" style="border:0" width="14" height="14" src="' . esc_url( $icon ) . '" alt="RSS" /></a> <a class="rsswidget" href="' . esc_url( $link ) . '">' . esc_html( $title ) . '</a>';
		}

		echo $args['before_widget'];
		if ( $title ) {
			echo $args['before_title'] . $title . $args['after_title'];
		}
		wp_widget_rss_output( $rss, $instance );
		echo $args['after_widget'];

		if ( ! is_wp_error( $rss ) ) {
			$rss->__destruct();
		}
		unset( $rss );
	}

	/**
	 * Handles updating settings for the current RSS widget instance.
	 *
	 * @since 2.8.0
	 *
	 * @param array $new_instance New settings for this instance as input by the user via
	 *                            WP_Widget::form().
	 * @param array $old_instance Old settings for this instance.
	 * @return array Updated settings to save.
	 */
	public function update( $new_instance, $old_instance ) {
		$testurl = ( isset( $new_instance['url'] ) && ( ! isset( $old_instance['url'] ) || ( $new_instance['url'] != $old_instance['url'] ) ) );
		return wp_widget_rss_process( $new_instance, $testurl );
	}

	/**
	 * Outputs the settings form for the RSS widget.
	 *
	 * @since 2.8.0
	 *
	 * @param array $instance Current settings.
	 */
	public function form( $instance ) {
		if ( empty( $instance ) ) {
			$instance = array(
				'title'        => '',
				'url'          => '',
				'items'        => 10,
				'error'        => false,
				'show_summary' => 0,
				'show_author'  => 0,
				'show_date'    => 0,
			);
		}
		$instance['number'] = $this->number;

		wp_widget_rss_form( $instance );
	}
}