First pass commentmeta implementation. See #2659 props scribu.

git-svn-id: http://svn.automattic.com/wordpress/trunk@11943 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/comment.php

@@ -361,6 +361,88 @@ function get_comment_count( $post_id = 0 ) {
 	return $comment_count;
 }
 
+//
+// Comment meta functions
+//
+
+/**
+ * Add meta data field to a comment.
+ *
+ * Post meta data is called "Custom Fields" on the Administration Panels.
+ *
+ * @since 2.9
+ * @uses add_metadata
+ * @link http://codex.wordpress.org/Function_Reference/add_comment_meta
+ *
+ * @param int $comment_id Post ID.
+ * @param string $key Metadata name.
+ * @param mixed $value Metadata value.
+ * @param bool $unique Optional, default is false. Whether the same key should not be added.
+ * @return bool False for failure. True for success.
+ */
+function add_comment_meta($comment_id, $meta_key, $meta_value, $unique = false) {
+	return add_metadata('comment', $comment_id, $meta_key, $meta_value, $unique);
+}
+
+/**
+ * Remove metadata matching criteria from a comment.
+ *
+ * You can match based on the key, or key and value. Removing based on key and
+ * value, will keep from removing duplicate metadata with the same key. It also
+ * allows removing all metadata matching key, if needed.
+ *
+ * @since 2.9
+ * @uses delete_metadata
+ * @link http://codex.wordpress.org/Function_Reference/delete_comment_meta
+ *
+ * @param int $comment_id comment ID
+ * @param string $meta_key Metadata name.
+ * @param mixed $meta_value Optional. Metadata value.
+ * @return bool False for failure. True for success.
+ */
+function delete_comment_meta($comment_id, $meta_key, $meta_value = '') {
+	return delete_metadata('comment', $comment_id, $meta_key, $meta_value);
+}
+
+/**
+ * Retrieve comment meta field for a comment.
+ *
+ * @since 2.9
+ * @uses get_metadata
+ * @link http://codex.wordpress.org/Function_Reference/get_comment_meta
+ *
+ * @param int $comment_id Post ID.
+ * @param string $key The meta key to retrieve.
+ * @param bool $single Whether to return a single value.
+ * @return mixed Will be an array if $single is false. Will be value of meta data field if $single
+ *  is true.
+ */
+function get_comment_meta($comment_id, $key, $single = false) {
+	return get_metadata('comment', $comment_id, $key, $single);
+}
+
+/**
+ * Update comment meta field based on comment ID.
+ *
+ * Use the $prev_value parameter to differentiate between meta fields with the
+ * same key and comment ID.
+ *
+ * If the meta field for the comment does not exist, it will be added.
+ *
+ * @since 2.9
+ * @uses update_metadata
+ * @link http://codex.wordpress.org/Function_Reference/update_comment_meta
+ *
+ * @param int $comment_id Post ID.
+ * @param string $key Metadata key.
+ * @param mixed $value Metadata value.
+ * @param mixed $prev_value Optional. Previous value to check before removing.
+ * @return bool False on failure, true if success.
+ */
+function update_comment_meta($comment_id, $meta_key, $meta_value, $prev_value = '') {
+	return update_metadata('comment', $comment_id, $meta_key, $meta_value, $prev_value);
+}
+
 /**
  * Sanitizes the cookies sent to the user already.
  *