To add a filter for submenu capabilities, you can utilize the add_submenu_page function, which allows you to specify the capability required to view the submenu. The key is to define the capability dynamically using a filter.
Step-by-Step Implementation
1. Define Your Custom Filter: First, create a custom filter that will allow you to modify the capability required to access the submenu. This filter returns the default capability unless overridden by hooked functions.
function custom_submenu_capability($capability) {
return apply_filters('custom_submenu_capability_filter', $capability);
}
2. Add Submenu With Dynamic Capability: When adding your submenu, use the custom_submenu_capability function to determine the required capability. Assume the default capability is 'manage_options', which you can override using the filter.
add_action('admin_menu', function() {
add_submenu_page(
'tools.php', // Parent slug
'My Custom Submenu', // Page title
'Custom Submenu', // Menu title
custom_submenu_capability('manage_options'), // Capability
'custom-submenu-slug', // Menu slug
'my_custom_submenu_page_callback' // Callback function
);
});
3. Hook Into Your Filter to Modify Capability: Depending on your application logic or conditions, hook into custom_submenu_capability_filter to modify the capability dynamically. For example, if you want to change the capability based on the current user’s role or another condition:
add_filter('custom_submenu_capability_filter', function($capability) {
if (current_user_can('edit_posts')) {
return 'edit_posts';
}
return $capability;
});
This example changes the required capability to 'edit_posts' if the current user has the edit_posts capability.
Conclusion
This implementation allows you to filter and adjust the capabilities required to view and access submenus dynamically. It’s flexible and can be adapted to various scenarios depending on your specific requirements or conditions.
