Don't hide early nav menu instructions until the menu is no longer empty. props koopersmith, see #13525

git-svn-id: http://svn.automattic.com/wordpress/trunk@14917 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/css/nav-menu.dev.css

@@ -409,6 +409,9 @@ body.js .item-order {
 }
 
 /* Menu editing */
+.menu-instructions-inactive {
+	display: none;
+}
 .menu-item-settings {
 	background: #F9F9F9;
 	display:block;

wp-admin/includes/nav-menu.php

@@ -962,6 +962,13 @@ function wp_get_nav_menu_to_edit( $menu_id = 0 ) {
 	// If the menu exists, get its items.
 	if ( is_nav_menu( $menu ) ) {
 		$menu_items = wp_get_nav_menu_items( $menu->term_id, array('post_status' => 'any') );
+		$result = '<div id="menu-instructions" class="post-body-plain';
+		$result .= ( ! empty($menu_items) ) ? ' menu-instructions-inactive">' : '">';
+		$result .= __('Select menu items (pages, categories, links) from the boxes at left to begin building your custom menu.');
+		$result .= '</div>';
+		
+		if( empty($menu_items) )
+			return $result;
 
 		$walker_class_name = apply_filters( 'wp_edit_nav_menu_walker', 'Walker_Nav_Menu_Edit', $menu_id );
 
@@ -970,7 +977,8 @@ function wp_get_nav_menu_to_edit( $menu_id = 0 ) {
 		else
 			return new WP_Error( 'menu_walker_not_exist', sprintf( __('The Walker class named <strong>%s</strong> does not exist.'), $walker_class_name ) );
 
-		return walk_nav_menu_tree( array_map('wp_setup_nav_menu_item', $menu_items), 0, (object) array('walker' => $walker ) );
+		$result .= walk_nav_menu_tree( array_map('wp_setup_nav_menu_item', $menu_items), 0, (object) array('walker' => $walker ) );
+		return $result;
 	} elseif ( is_wp_error( $menu ) ) {
 		return $menu;
 	}

wp-admin/js/nav-menu.dev.js

@@ -535,7 +535,10 @@ var wpNavMenu;
 			};
 
 			$.post( ajaxurl, params, function(menuMarkup) {
+				var ins = $('#menu-instructions');
 				processMethod(menuMarkup, params);
+				if( ! ins.hasClass('menu-instructions-inactive') && ins.siblings().length )
+					ins.addClass('menu-instructions-inactive');
 				callback();
 			});
 		},
@@ -826,8 +829,11 @@ var wpNavMenu;
 					opacity : 0,
 					height: 0
 				}, 350, function() {
+					var ins = $('#menu-instructions');
 					el.remove();
 					children.shiftDepthClass(-1).updateParentMenuItemDBId();
+					if( ! ins.siblings().length )
+						ins.removeClass('menu-instructions-inactive');
 				});
 		},