wp/wp-includes/post-thumbnail-template.php
changeset 0 d970ebf37754
child 5 5e2f62d02dcd
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/post-thumbnail-template.php	Wed Nov 06 03:21:17 2013 +0000
@@ -0,0 +1,142 @@
+<?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
+ *
+ * @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 );
+}