Elgg contains helper code to build menus throughout the site.
Every single menu requires a name, as does every single menu item. These are required in order to allow easy overriding and manipulation, as well as to provide hooks for theming.
Contents
Basic functionalities can be achieved through these two functions:
- elgg_register_menu_item() to add an item to a menu
- elgg_unregister_menu_item() to remove an item from a menu
You normally want to call them from your plugin's init function.
// Add a new menu item to the site main menu
elgg_register_menu_item('site', array(
'name' => 'itemname',
'text' => 'This is text of the item',
'href' => '/item/url',
));// Remove the "Elgg" logo from the topbar menu
elgg_unregister_menu_item('topbar', 'elgg_logo');You can also register page menu items to the admin backend menu. When registering for the admin menu you can set the context of the menu items to admin so the menu items only show in the admin context. There are 3 default sections to add your menu items to.
- administer for daily tasks, usermanagement and other actionable tasks
- configure for settings, configuration and utilities that configure stuff
- information for statistics, overview of information or status
You can get more control over menus by using plugin hooks </design/events> and the public methods provided by the ElggMenuItem class.
- There are two hooks that can be used to modify a menu:
'register', 'menu:<menu name>'to add or modify items (especially in dynamic menus)'prepare', 'menu:<menu name>'to modify the structure of the menu before it is displayed
When you register a plugin hook handler, replace the <menu name> part with the internal name of the menu.
The third parameter passed into a menu handler contains all the menu items that have been registered so far by Elgg core and other enabled plugins. In the handler we can loop through the menu items and use the class methods to interact with the properties of the menu item.
Example 1: Change the URL for menu item called "albums" in the owner_block menu:
/**
* Initialize the plugin
*/
function my_plugin_init() {
// Register a plugin hook handler for the owner_block menu
elgg_register_plugin_hook_handler('register', 'menu:owner_block', 'my_owner_block_menu_handler');
}
/**
* Change the URL of the "Albums" menu item in the owner_block menu
*/
function my_owner_block_menu_handler($hook, $type, $items, $params) {
$owner = $params['entity'];
// Owner can be either user or a group, so we
// need to take both URLs into consideration:
switch ($owner->getType()) {
case 'user':
$url = "album/owner/{$owner->guid}";
break;
case 'group':
$url = "album/group/{$owner->guid}";
break;
}
if ($items->has('albums')) {
$items->get('albums')->setURL($url);
}
return $items;
}- Example 2: Modify the
entitymenu for theElggBlogobjects - Remove the thumb icon
- Change the "Edit" text into a custom icon
/**
* Initialize the plugin
*/
function my_plugin_init() {
// Register a plugin hook handler for the entity menu
elgg_register_plugin_hook_handler('register', 'menu:entity', 'my_entity_menu_handler');
}
/**
* Customize the entity menu for ElggBlog objects
*/
function my_entity_menu_handler($hook, $type, $items, $params) {
// The entity can be found from the $params parameter
$entity = $params['entity'];
// We want to modify only the ElggBlog objects, so we
// return immediately if the entity is something else
if (!$entity instanceof ElggBlog) {
return $menu;
}
$items->remove('likes');
if ($items->has('edit')) {
$items->get('edit')->setText('Modify');
$items->get('edit')->icon = 'pencil';
}
return $items;
}Elgg provides multiple different menus by default. Sometimes you may however need some menu items that don't fit in any of the existing menus. If this is the case, you can create your very own menu with the elgg_view_menu() function. You must call the function from the view, where you want to menu to be displayed.
Example: Display a menu called "my_menu" that displays it's menu items in alphapetical order:
// in a resource view
echo elgg_view_menu('my_menu', array('sort_by' => 'text'));You can now add new items to the menu like this:
// in plugin init
elgg_register_menu_item('my_menu', array(
'name' => 'my_page',
'href' => 'path/to/my_page',
'text' => elgg_echo('my_plugin:my_page'),
));Furthermore it is now possible to modify the menu using the hooks 'register', 'menu:my_menu' and 'prepare', 'menu:my_menu'.
Child menus can be configured using child_menu factory option on the parent item.
child_menu options array accepts display parameter, which can be used to set the child menu to open as dropdown or be displayed via toggle. All other key value pairs will be passed as attributes to the ul element.
// Register a parent menu item that has a dropdown submenu
elgg_register_menu_item('my_menu', array(
'name' => 'parent_item',
'href' => '#',
'text' => 'Show dropdown menu',
'child_menu' => [
'display' => 'dropdown',
'class' => 'elgg-additional-child-menu-class',
'data-position' => json_encode([
'at' => 'right bottom',
'my' => 'right top',
'collision' => 'fit fit',
]),
'data-foo' => 'bar',
'id' => 'dropdown-menu-id',
],
));
// Register a parent menu item that has a hidden submenu toggled when item is clicked
elgg_register_menu_item('my_menu', array(
'name' => 'parent_item',
'href' => '#',
'text' => 'Show submenu',
'child_menu' => [
'display' => 'dropdown',
'class' => 'elgg-additional-submenu-class',
'data-toggle-duration' => 'medium',
'data-foo' => 'bar2',
'id' => 'submenu-id',
],
));The menu name, section names, and item names are all embedded into the HTML as CSS classes (normalized to contain only hyphens, rather that underscores or colons). This increases the size of the markup slightly but provides themers with a high degree of control and flexibility when styling the site.
Example: The following would be the output of the foo menu with sections alt and default containing items baz and bar respectively.
<ul class="elgg-menu elgg-menu-foo elgg-menu-foo-alt">
<li class="elgg-menu-item elgg-menu-item-baz"></li>
</ul>
<ul class="elgg-menu elgg-menu-foo elgg-menu-foo-default">
<li class="elgg-menu-item elgg-menu-item-bar"></li>
</ul>There are situations where you wish to toggle menu items that are actions that are the opposite of each other and ajaxify them. E.g. like/unlike, friend/unfriend, ban/unban, etc. Elgg has built-in support for this kind of actions. When you register a menu item you can provide a name of the menu item (in the same menu) that should be toggled. An ajax call will be made using the href of the menu item.
elgg_register_menu_item('my_menu', [
'name' => 'like',
'data-toggle' => 'unlike',
'href' => 'action/like',
'text' => elgg_echo('like'),
]);
elgg_register_menu_item('my_menu', [
'name' => 'unlike',
'data-toggle' => 'like',
'href' => 'action/unlike',
'text' => elgg_echo('unlike'),
]);Note
The menu items are optimistically toggled. This means the menu items are toggled before the actions finish. If the actions fail, the menu items will be toggled back.
It is common that menu items rely on JavaScript. You can bind client-side events to menu items by placing your JavaScript into AMD module and defining the requirement during the registration.
elgg_register_menu_item('my_menu', array(
'name' => 'hide_on_click',
'href' => '#',
'text' => elgg_echo('hide:on:click'),
'item_class' => '.hide-on-click',
'deps' => ['navigation/menu/item/hide_on_click'],
));// in navigation/menu/item/hide_on_click.js
define(function(require) {
var $ = require('jquery');
$(document).on('click', '.hide-on-click', function(e) {
e.preventDefault();
$(this).hide();
});
});