<?php /** * WordPress Post Thumbnail Template Functions. * * Support for post thumbnails * Themes function.php must call add_theme_support( 'post-thumbnails' ) to use these. * * @package WordPress * @subpackage Template */ /** * Check if post has an image attached. * * @since 2.9.0 * * @param int $post_id Optional. Post ID. * @return bool Whether post has an image attached. */ function has_post_thumbnail( $post_id = null ) { return (bool) get_post_thumbnail_id( $post_id ); } /** * Retrieve Post Thumbnail ID. * * @since 2.9.0 * * @param int $post_id Optional. Post ID. * @return int */ function get_post_thumbnail_id( $post_id = null ) { $post_id = ( null === $post_id ) ? get_the_ID() : $post_id; return get_post_meta( $post_id, '_thumbnail_id', true ); } /** * Display Post Thumbnail. * * @since 2.9.0 * * @param string|array $size Optional. Image size. Defaults to 'post-thumbnail', which theme sets using set_post_thumbnail_size( $width, $height, $crop_flag );. * @param string|array $attr Optional. Query string or array of attributes. */ function the_post_thumbnail( $size = 'post-thumbnail', $attr = '' ) { echo get_the_post_thumbnail( null, $size, $attr ); } /** * Update cache for thumbnails in the current loop * * @since 3.2.0 * * @param object $wp_query Optional. A WP_Query instance. Defaults to the $wp_query global. */ function update_post_thumbnail_cache( $wp_query = null ) { if ( ! $wp_query ) $wp_query = $GLOBALS['wp_query']; if ( $wp_query->thumbnails_cached ) return; $thumb_ids = array(); foreach ( $wp_query->posts as $post ) { if ( $id = get_post_thumbnail_id( $post->ID ) ) $thumb_ids[] = $id; } if ( ! empty ( $thumb_ids ) ) { _prime_post_caches( $thumb_ids, false, true ); } $wp_query->thumbnails_cached = true; } /** * Retrieve Post Thumbnail. * * @since 2.9.0 * * @param int $post_id Optional. Post ID. * @param string $size Optional. Image size. Defaults to 'post-thumbnail'. * @param string|array $attr Optional. Query string or array of attributes. */ function get_the_post_thumbnail( $post_id = null, $size = 'post-thumbnail', $attr = '' ) { $post_id = ( null === $post_id ) ? get_the_ID() : $post_id; $post_thumbnail_id = get_post_thumbnail_id( $post_id ); /** * Filter the post thumbnail size. * * @since 2.9.0 * * @param string $size The post thumbnail size. */ $size = apply_filters( 'post_thumbnail_size', $size ); if ( $post_thumbnail_id ) { /** * Fires before fetching the post thumbnail HTML. * * Provides "just in time" filtering of all filters in wp_get_attachment_image(). * * @since 2.9.0 * * @param string $post_id The post ID. * @param string $post_thumbnail_id The post thumbnail ID. * @param string $size The post thumbnail size. */ do_action( 'begin_fetch_post_thumbnail_html', $post_id, $post_thumbnail_id, $size ); if ( in_the_loop() ) update_post_thumbnail_cache(); $html = wp_get_attachment_image( $post_thumbnail_id, $size, false, $attr ); /** * Fires after fetching the post thumbnail HTML. * * @since 2.9.0 * * @param string $post_id The post ID. * @param string $post_thumbnail_id The post thumbnail ID. * @param string $size The post thumbnail size. */ do_action( 'end_fetch_post_thumbnail_html', $post_id, $post_thumbnail_id, $size ); } else { $html = ''; } /** * Filter the post thumbnail HTML. * * @since 2.9.0 * * @param string $html The post thumbnail HTML. * @param string $post_id The post ID. * @param string $post_thumbnail_id The post thumbnail ID. * @param string $size The post thumbnail size. * @param string $attr Query string of attributes. */ return apply_filters( 'post_thumbnail_html', $html, $post_id, $post_thumbnail_id, $size, $attr ); }