From d9e724974f6c7d1ca0756f4c85240fc919130393 Mon Sep 17 00:00:00 2001
From: Andrew Ozz <azaozz@git.wordpress.org>
Date: Sat, 2 May 2009 00:21:16 +0000
Subject: [PATCH] Add action "in_widget_form" allowing plugins to add extra
 fields, don't show "Save" button if a widget doesn't have settings form,
 fixes #9651

git-svn-id: https://develop.svn.wordpress.org/trunk@11155 602fd350-edb4-49c9-b593-d223f7449a82
---
 wp-admin/includes/widgets.php |  4 ++--
 wp-includes/widgets.php       | 12 +++++++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/wp-admin/includes/widgets.php b/wp-admin/includes/widgets.php
index 771294b73c..cf2a2b81e9 100644
--- a/wp-admin/includes/widgets.php
+++ b/wp-admin/includes/widgets.php
@@ -166,7 +166,7 @@ function wp_widget_control( $sidebar_args ) {
 	unset($wp_registered_widgets[$widget_id]['_callback']);
 
 	$widget_title = wp_specialchars( strip_tags( $sidebar_args['widget_name'] ) );
-	$has_form = 0;
+	$has_form = 'noform';
 
 	echo $sidebar_args['before_widget']; ?>
 	<div class="widget-top">
@@ -195,7 +195,7 @@ function wp_widget_control( $sidebar_args ) {
 
 	<div class="widget-control-actions">
 		<a class="button widget-control-remove alignleft" href="<?php echo $edit ? clean_url( add_query_arg( array( 'remove' => $id_format, 'key' => $key, '_wpnonce' => $nonce ) ) ) : '#remove'; ?>"><?php _e('Remove'); ?></a>
-<?php		if ( false !== $has_form ) { ?>
+<?php		if ( 'noform' !== $has_form ) { ?>
 		<input type="submit" name="savewidget" class="button-primary widget-control-save alignright" value="<?php _e('Save'); ?>" />
 <?php		} ?>
 		<br class="clear" />
diff --git a/wp-includes/widgets.php b/wp-includes/widgets.php
index 945af1ecc0..eb3e3ca994 100644
--- a/wp-includes/widgets.php
+++ b/wp-includes/widgets.php
@@ -65,7 +65,7 @@ class WP_Widget {
 	 */
 	function form($instance) {
 		echo '<p>' . __('There are no options for this widget.') . '</p>';
-		return false;
+		return 'noform';
 	}
 
 	// Functions you'll need to call.
@@ -259,8 +259,14 @@ class WP_Widget {
 
 		// filters the widget admin form before displaying, return false to stop displaying it
 		$instance = apply_filters('widget_form_callback', $instance, $this);
-		if ( false !== $instance )
-			$this->form($instance);
+
+		$return = null;
+		if ( false !== $instance ) {
+			$return = $this->form($instance);
+			if ( 'noform' !== $return )
+				do_action_ref_array( 'in_widget_form', array(&$this) ); // add extra fields in the widget form
+		}
+		return $return;
 	}
 
 	/** Helper function: Registers a single instance. */