Today I faced a problem. I am building a website for a customer using WordPress. This web site is huge, about 200 pages in a hierarchical organization. I came to the point where I needed a custom menu. I didn’t need the “Home” link and some other pages to show. And I needed some other menu customizations.
I wanted to use the new WordPress navigation menu system. But, as I didn’t feel like duplicating each page as a menu item, one by one, I started digging into the code and well, I figured out how to automatically populate a chosen “page menu” with its child pages.
Adding the checkbox
I wanted to be able to specify witch menu item to auto-populate with its child pages. For that, a checkbox was needed for each menu item.
The nav-menu items forms are generated by a walker (Walker_Nav_Menu_Edit) witch has no action hook to add any field, but, I found a way to tell wordpress to use my own. For that you need to duplicate the Walker_Nav_Menu_Edit and then add the checkbox, something like:
</p>
<p class="description description-wide">
<label for="edit-menu-item-showsub-<?php echo $item_id; ?>">
<input type="checkbox" id="edit-menu-item-showsub-<?php echo $item_id; ?>" class="widefat edit-menu-item-showsub" name="menu-item-showsub[<?php echo $item_id; ?>]" value="1" <?php if($item->showsub == '1') echo 'checked="checked"'; ?>/>
<?php _e( 'Afficher les sous-pages automatiquement' ); ?>
</label>
</p>
<div class="menu-item-actions description-wide submitbox">
And then tell WordPress to use your own walker:
function custom_walker($a) {
return 'Custom_Walker_Nav_Menu_Edit';
}
$walker_class_name = add_filter( 'wp_edit_nav_menu_walker', 'custom_walker');
Saving the checkbox state
We now need to save the checkbox state when the nav-menu is saved. A simple function will do it:
/**
* Saves the new field
*/
function common_wp_update_nav_menu_item($menu_id, $menu_item_db_id, $args) {
$args['menu-item-showsub'] = isset( $_POST['menu-item-showsub'][$menu_item_db_id] ) ? $_POST['menu-item-showsub'][$menu_item_db_id] : '';
if ( empty( $args['menu-item-showsub'] ) ) {
$args['menu-item-showsub'] = '0';
}
update_post_meta( $menu_item_db_id, '_menu_item_showsub', $args['menu-item-showsub'] );
}
add_action('wp_update_nav_menu_item', 'common_wp_update_nav_menu_item',10,3 );
We then need to have our new field value available as a property of the nav menu item object:
/**
* Setup the nav menu object to have the showsub propertie
*/
function custom_wp_setup_nav_menu_item($menu_item)
{
if ( isset( $menu_item->post_type ) ) {
if ( 'nav_menu_item' == $menu_item->post_type ) {
$menu_item->showsub = empty( $menu_item->showsub ) ? get_post_meta( $menu_item->ID, '_menu_item_showsub', true ) : $menu_item->showsub;
}
}
return $menu_item;
}
add_filter( 'wp_setup_nav_menu_item', 'custom_wp_setup_nav_menu_item' );
Showing the child pages
Finally we need the wp_nav_menu function to take in account the new ‘showsub’ property and to list child pages when it is set:
function custom_walker_nav_menu_start_el ( $item_output, $item, $depth, $args)
{
if( isset($item->showsub) && $item->showsub =='1') {
$args = array( 'depth' => 0,
'child_of' => 449,
'echo' => 0, 'title_li' => '' );
$item_output = $item_output . '<ul clas="children" >' . wp_list_pages($args) . '</ul>';
}
return $item_output;
}
add_filter( 'walker_nav_menu_start_el', 'custom_walker_nav_menu_start_el', 10,4 );
Here is the full script to donwload.
add_filter( 'wp_edit_nav_menu_walker', 'custom_walker');
function custom_walker($a) {
return 'Custom_Walker_Nav_Menu_Edit';
}
/**
* Create HTML list of nav menu input items.
*
* @package WordPress
* @since 3.0.0
* @uses Walker_Nav_Menu
*/
class Custom_Walker_Nav_Menu_Edit extends Walker_Nav_Menu {
/**
* @see Walker_Nav_Menu::start_lvl()
* @since 3.0.0
*
* @param string $output Passed by reference.
* @param int $depth Depth of page.
*/
function start_lvl(&$output) {}
/**
* @see Walker_Nav_Menu::end_lvl()
* @since 3.0.0
*
* @param string $output Passed by reference.
* @param int $depth Depth of page.
*/
function end_lvl(&$output) {
}
/**
* @see Walker::start_el()
* @since 3.0.0
*
* @param string $output Passed by reference. Used to append additional content.
* @param object $item Menu item data object.
* @param int $depth Depth of menu item. Used for padding.
* @param int $current_page Menu item ID.
* @param object $args
*/
function start_el(&$output, $item, $depth, $args) {
global $_wp_nav_menu_max_depth;
$_wp_nav_menu_max_depth = $depth > $_wp_nav_menu_max_depth ? $depth : $_wp_nav_menu_max_depth;
$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
ob_start();
$item_id = esc_attr( $item->ID );
$removed_args = array(
'action',
'customlink-tab',
'edit-menu-item',
'menu-item',
'page-tab',
'_wpnonce',
);
$original_title = '';
if ( 'taxonomy' == $item->type ) {
$original_title = get_term_field( 'name', $item->object_id, $item->object, 'raw' );
} elseif ( 'post_type' == $item->type ) {
$original_object = get_post( $item->object_id );
$original_title = $original_object->post_title;
}
$classes = array(
'menu-item menu-item-depth-' . $depth,
'menu-item-' . esc_attr( $item->object ),
'menu-item-edit-' . ( ( isset( $_GET['edit-menu-item'] ) && $item_id == $_GET['edit-menu-item'] ) ? 'active' : 'inactive'),
);
$title = $item->title;
if ( isset( $item->post_status ) && 'draft' == $item->post_status ) {
$classes[] = 'pending';
/* translators: %s: title of menu item in draft status */
$title = sprintf( __('%s (Pending)'), $item->title );
}
$title = empty( $item->label ) ? $title : $item->label;
?>
<li id="menu-item-<?php echo $item_id; ?>" class="<?php echo implode(' ', $classes ); ?>">
<dl class="menu-item-bar">
<dt class="menu-item-handle">
<span class="item-title"><?php echo esc_html( $title ); ?></span>
<span class="item-controls">
<span class="item-type"><?php echo esc_html( $item->type_label ); ?></span>
<span class="item-order">
<a href="<?php
echo wp_nonce_url(
add_query_arg(
array(
'action' => 'move-up-menu-item',
'menu-item' => $item_id,
),
remove_query_arg($removed_args, admin_url( 'nav-menus.php' ) )
),
'move-menu_item'
);
?>" class="item-move-up"><abbr title="<?php esc_attr_e('Move up'); ?>">↑</abbr></a>
|
<a href="<?php
echo wp_nonce_url(
add_query_arg(
array(
'action' => 'move-down-menu-item',
'menu-item' => $item_id,
),
remove_query_arg($removed_args, admin_url( 'nav-menus.php' ) )
),
'move-menu_item'
);
?>" class="item-move-down"><abbr title="<?php esc_attr_e('Move down'); ?>">↓</abbr></a>
</span>
<a class="item-edit" id="edit-<?php echo $item_id; ?>" title="<?php _e('Edit Menu Item'); ?>" href="<?php
echo ( isset( $_GET['edit-menu-item'] ) && $item_id == $_GET['edit-menu-item'] ) ? admin_url( 'nav-menus.php' ) : add_query_arg( 'edit-menu-item', $item_id, remove_query_arg( $removed_args, admin_url( 'nav-menus.php#menu-item-settings-' . $item_id ) ) );
?>"><?php _e( 'Edit Menu Item' ); ?></a>
</span>
</dt>
</dl>
<div class="menu-item-settings" id="menu-item-settings-<?php echo $item_id; ?>">
<?php if( 'custom' == $item->type ) : ?>
<p class="field-url description description-wide">
<label for="edit-menu-item-url-<?php echo $item_id; ?>">
<?php _e( 'URL' ); ?><br />
<input type="text" id="edit-menu-item-url-<?php echo $item_id; ?>" class="widefat code edit-menu-item-url" name="menu-item-url[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->url ); ?>" />
</label>
</p>
<?php endif; ?>
<p class="description description-thin">
<label for="edit-menu-item-title-<?php echo $item_id; ?>">
<?php _e( 'Navigation Label' ); ?><br />
<input type="text" id="edit-menu-item-title-<?php echo $item_id; ?>" class="widefat edit-menu-item-title" name="menu-item-title[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->title ); ?>" />
</label>
</p>
<p class="description description-thin">
<label for="edit-menu-item-attr-title-<?php echo $item_id; ?>">
<?php _e( 'Title Attribute' ); ?><br />
<input type="text" id="edit-menu-item-attr-title-<?php echo $item_id; ?>" class="widefat edit-menu-item-attr-title" name="menu-item-attr-title[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->post_excerpt ); ?>" />
</label>
</p>
<p class="field-link-target description description-thin">
<label for="edit-menu-item-target-<?php echo $item_id; ?>">
<?php _e( 'Link Target' ); ?><br />
<select id="edit-menu-item-target-<?php echo $item_id; ?>" class="widefat edit-menu-item-target" name="menu-item-target[<?php echo $item_id; ?>]">
<option value="" <?php selected( $item->target, ''); ?>><?php _e('Same window or tab'); ?></option>
<option value="_blank" <?php selected( $item->target, '_blank'); ?>><?php _e('New window or tab'); ?></option>
</select>
</label>
</p>
<p class="field-css-classes description description-thin">
<label for="edit-menu-item-classes-<?php echo $item_id; ?>">
<?php _e( 'CSS Classes (optional)' ); ?><br />
<input type="text" id="edit-menu-item-classes-<?php echo $item_id; ?>" class="widefat code edit-menu-item-classes" name="menu-item-classes[<?php echo $item_id; ?>]" value="<?php echo esc_attr( implode(' ', $item->classes ) ); ?>" />
</label>
</p>
<p class="field-xfn description description-thin">
<label for="edit-menu-item-xfn-<?php echo $item_id; ?>">
<?php _e( 'Link Relationship (XFN)' ); ?><br />
<input type="text" id="edit-menu-item-xfn-<?php echo $item_id; ?>" class="widefat code edit-menu-item-xfn" name="menu-item-xfn[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->xfn ); ?>" />
</label>
</p>
<p class="field-description description description-wide">
<label for="edit-menu-item-description-<?php echo $item_id; ?>">
<?php _e( 'Description' ); ?><br />
<textarea id="edit-menu-item-description-<?php echo $item_id; ?>" class="widefat edit-menu-item-description" rows="3" cols="20" name="menu-item-description[<?php echo $item_id; ?>]"><?php echo esc_html( $item->description ); ?></textarea>
<span class="description"><?php _e('The description will be displayed in the menu if the current theme supports it.'); ?></span>
</label>
</p>
<p class="field-description description description-wide">
<label for="edit-menu-item-description-<?php echo $item_id; ?>">
<?php _e( 'Description' ); ?><br />
<textarea id="edit-menu-item-description-<?php echo $item_id; ?>" class="widefat edit-menu-item-description" rows="3" cols="20" name="menu-item-description[<?php echo $item_id; ?>]"><?php echo esc_html( $item->description ); ?></textarea>
<span class="description"><?php _e('The description will be displayed in the menu if the current theme supports it.'); ?></span>
</label>
</p>
<p class="description description-wide">
<label for="edit-menu-item-showsub-<?php echo $item_id; ?>">
<input type="checkbox" id="edit-menu-item-showsub-<?php echo $item_id; ?>" class="widefat edit-menu-item-showsub" name="menu-item-showsub[<?php echo $item_id; ?>]" value="1" <?php if($item->showsub == '1') echo 'checked="checked"'; ?>/>
<?php _e( 'Afficher les sous-pages automatiquement' ); ?>
</label>
</p>
<div class="menu-item-actions description-wide submitbox">
<?php if( 'custom' != $item->type ) : ?>
<p class="link-to-original">
<?php printf( __('Original: %s'), '<a href="' . esc_attr( $item->url ) . '">' . esc_html( $original_title ) . '</a>' ); ?>
</p>
<?php endif; ?>
<a class="item-delete submitdelete deletion" id="delete-<?php echo $item_id; ?>" href="<?php
echo wp_nonce_url(
add_query_arg(
array(
'action' => 'delete-menu-item',
'menu-item' => $item_id,
),
remove_query_arg($removed_args, admin_url( 'nav-menus.php' ) )
),
'delete-menu_item_' . $item_id
); ?>"><?php _e('Remove'); ?></a> <span class="meta-sep"> | </span> <a class="item-cancel submitcancel" id="cancel-<?php echo $item_id; ?>" href="<?php echo add_query_arg( array('edit-menu-item' => $item_id, 'cancel' => time()), remove_query_arg( $removed_args, admin_url( 'nav-menus.php' ) ) );
?>#menu-item-settings-<?php echo $item_id; ?>"><?php _e('Cancel'); ?></a>
</div>
<input class="menu-item-data-db-id" type="hidden" name="menu-item-db-id[<?php echo $item_id; ?>]" value="<?php echo $item_id; ?>" />
<input class="menu-item-data-object-id" type="hidden" name="menu-item-object-id[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->object_id ); ?>" />
<input class="menu-item-data-object" type="hidden" name="menu-item-object[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->object ); ?>" />
<input class="menu-item-data-parent-id" type="hidden" name="menu-item-parent-id[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->menu_item_parent ); ?>" />
<input class="menu-item-data-position" type="hidden" name="menu-item-position[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->menu_order ); ?>" />
<input class="menu-item-data-type" type="hidden" name="menu-item-type[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->type ); ?>" />
</div><!-- .menu-item-settings-->
<ul class="menu-item-transport"></ul>
<?php
$output .= ob_get_clean();
}
}
Pingback: Ticket #14414 (Add an action hook to add fields to nav_menu items form) created | Wordpress Services
Thanks for this post.
Is it difficult to show the posts of a certain categorie instead of subpages
It should no:. modify the $args array. It basically uses the same parameters as get_posts() function
I thought so to.
But get_posts() returns an array that cannot be converted to a string.
Other question. Why do you use ‘child_of’ => 449 instead of ‘child_of’ => $item->object_id?
Thnks