这将向菜单项“编辑”添加自定义字段。但是，在为新添加的菜单项保存菜单之前，您不会看到自定义字段。首次添加项目时，您将只看到标准字段。保存后，新字段也可用于编辑。如果添加其他菜单项，则必须再次保存菜单以查看和编辑新添加项的自定义字段。我希望这个解释有道理。
我能够创建并使用自定义的walker来创建菜单项编辑字段。当您第一次将菜单项添加到菜单时，它似乎完全是用jQuery而不是walker创建的，这就是为什么在保存之后才会看到自定义字段的原因。
我创造性地将我添加的自定义字段称为“自定义”。因此，您可以更改/编辑/复制所需的任何值。walker中有一些注释可以显示我在哪里添加了新字段。
我希望这是有益的。
<?php
/**
* @package nav-menu-custom-fields
* @version 0.1.0
*/
/*
Plugin Name: Nav Menu Custom Fields
*/
/*
* Saves new field to postmeta for navigation
*/
add_action(\'wp_update_nav_menu_item\', \'custom_nav_update\',10, 3);
function custom_nav_update($menu_id, $menu_item_db_id, $args ) {
if ( is_array($_REQUEST[\'menu-item-custom\']) ) {
$custom_value = $_REQUEST[\'menu-item-custom\'][$menu_item_db_id];
update_post_meta( $menu_item_db_id, \'_menu_item_custom\', $custom_value );
}
}
/*
* Adds value of new field to $item object that will be passed to Walker_Nav_Menu_Edit_Custom
*/
add_filter( \'wp_setup_nav_menu_item\',\'custom_nav_item\' );
function custom_nav_item($menu_item) {
$menu_item->custom = get_post_meta( $menu_item->ID, \'_menu_item_custom\', true );
return $menu_item;
}
add_filter( \'wp_edit_nav_menu_walker\', \'custom_nav_edit_walker\',10,2 );
function custom_nav_edit_walker($walker,$menu_id) {
return \'Walker_Nav_Menu_Edit_Custom\';
}
/**
* Copied from Walker_Nav_Menu_Edit class in core
*
* Create HTML list of nav menu input items.
*
* @package WordPress
* @since 3.0.0
* @uses Walker_Nav_Menu
*/
class Walker_Nav_Menu_Edit_Custom extends Walker_Nav_Menu {
/**
* @see Walker_Nav_Menu::start_lvl()
* @since 3.0.0
*
* @param string $output Passed by reference.
*/
function start_lvl(&$output) {}
/**
* @see Walker_Nav_Menu::end_lvl()
* @since 3.0.0
*
* @param string $output Passed by reference.
*/
function end_lvl(&$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 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\' );
if ( is_wp_error( $original_title ) )
$original_title = false;
} 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 ( ! empty( $item->_invalid ) ) {
$classes[] = \'menu-item-invalid\';
/* translators: %s: title of menu item which is invalid */
$title = sprintf( __( \'%s (Invalid)\' ), $item->title );
} elseif ( 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 hide-if-js">
<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 esc_attr_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">
<label for="edit-menu-item-target-<?php echo $item_id; ?>">
<input type="checkbox" id="edit-menu-item-target-<?php echo $item_id; ?>" value="_blank" name="menu-item-target[<?php echo $item_id; ?>]"<?php checked( $item->target, \'_blank\' ); ?> />
<?php _e( \'Open link in a new window/tab\' ); ?>
</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_escaped ?></textarea>
<span class="description"><?php _e(\'The description will be displayed in the menu if the current theme supports it.\'); ?></span>
</label>
</p>
<?php
/*
* This is the added field
*/
?>
<p class="field-custom description description-wide">
<label for="edit-menu-item-custom-<?php echo $item_id; ?>">
<?php _e( \'Custom\' ); ?><br />
<input type="text" id="edit-menu-item-custom-<?php echo $item_id; ?>" class="widefat code edit-menu-item-custom" name="menu-item-custom[<?php echo $item_id; ?>]" value="<?php echo esc_attr( $item->custom ); ?>" />
</label>
</p>
<?php
/*
* end added field
*/
?>
<div class="menu-item-actions description-wide submitbox">
<?php if( \'custom\' != $item->type && $original_title !== false ) : ?>
<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 esc_url( 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();
}
}
?>
