Reconsidering Custom Renderers
One of the coolest new features in Moodle 2 is the fact that the core uses a series of renderes to output the final HTML, and that these renderers can extended or even overwritten by a plugin. One of the first things that people did was take the custommenu renderer and extend it to include theme-specific menu items. I think the first person to do this was Mary Evans (currently) of New School Learning in her theme Aardvark Makeover. (note: please don’t bug Mary if you decide to use that theme, she’s moved on to bigger and better themes)
Of course since Mary did the heaving lifting I figured “Why not?” since I was currently in process of porting Zebra to Moodle 2. So some serious copy-pasta ensued and I had my cool little home icon and calendar in the custommenu. Now a year later there has been some cool development in the core to the custommenu and I realized how much I’ve been missing out on by killing YUI in my renderer, so I decided to rethink my approach.
Here is my original renderers.php:
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* zebra theme renderer override functions
*
* @package theme_zebra
* @copyright 2011 Danny Wahl
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
/**
* Extends the core renderer
*
* Core renderer is extended in order to add extra items to the custom menu
*/
class theme_zebra_core_renderer extends core_renderer {
/**
* Renders a custom menu object (located in outputcomponents.php)
*
* The custom menu this method override the render_custom_menu function
* in outputrenderers.php
* @staticvar int $menucount
* @param custom_menu $menu
* @return string
*/
protected function render_custom_menu(custom_menu $menu) {
$branchlabel = " ";
$branchurl = new moodle_url('/index.php');
$branchtitle = get_string('menuhome','theme_zebra');
$branchsort = -1;
$branch = $menu->add($branchlabel, $branchurl, $branchtitle, $branchsort);
$branchlabel = date("F j, Y");
$branchurl = new moodle_url('/calendar/view.php');
$branchtitle = get_string('menutoday','theme_zebra');
$branchsort = +10000;
$branch = $menu->add($branchlabel, $branchurl, $branchtitle, $branchsort);
// If the menu has no children return an empty string
if (!$menu->has_children()) {
return '';
}
// Initialise this custom menu
$content = html_writer::start_tag('ul', array('class'=>'dropdown dropdown-horizontal'));
// Render each child
foreach ($menu->get_children() as $item) {
$content .= $this->render_custom_menu_item($item);
}
// Close the open tags
$content .= html_writer::end_tag('ul');
// Return the custom menu
return $content;
}
/**
* Renders a custom menu node as part of a submenu
*
* The custom menu this method override the render_custom_menu_item function
* in outputrenderers.php
*
* @see render_custom_menu()
*
* @staticvar int $submenucount
* @param custom_menu_item $menunode
* @return string
*/
protected function render_custom_menu_item(custom_menu_item $menunode) {
// Required to ensure we get unique trackable id's
static $submenucount = 0;
$content = html_writer::start_tag('li');
if ($menunode->has_children()) {
// If the child has menus render it as a sub menu
$submenucount++;
if ($menunode->get_url() !== null) {
$url = $menunode->get_url();
} else {
$url = '#cm_submenu_'.$submenucount;
}
$content .= html_writer::start_tag('span', array('class'=>'customitem'));
$content .= html_writer::link($url, $menunode->get_text(), array('title'=>$menunode->get_title()));
$content .= html_writer::end_tag('span');
$content .= html_writer::start_tag('ul');
foreach ($menunode->get_children() as $menunode) {
$content .= $this->render_custom_menu_item($menunode);
}
$content .= html_writer::end_tag('ul');
} else {
// The node doesn't have children so produce a final menuitem
if ($menunode->get_url() !== null) {
$url = $menunode->get_url();
} else {
$url = '#';
}
$content .= html_writer::link($url, $menunode->get_text(), array('title'=>$menunode->get_title()));
}
$content .= html_writer::end_tag('li');
// Return the sub menu
return $content;
}
/**
* Copied from core_renderer with one minor change
*
* Changes $this->output->render() to $this->render()
*/
protected function render_navigation_node(navigation_node $item) {
$content = $item->get_content();
$title = $item->get_title();
if ($item->icon instanceof renderable && !$item->hideicon) {
$icon = $this->render($item->icon);
$content = $icon.$content;
}
if ($item->helpbutton !== null) {
$content = trim($item->helpbutton).html_writer::tag('span', $content, array('class'=>'clearhelpbutton'));
}
if ($content === '') {
return '';
}
if ($item->action instanceof action_link) {
$link = $item->action;
if ($item->hidden) {
$link->add_class('dimmed');
}
$content = $this->render($link);
} else if ($item->action instanceof moodle_url) {
$attributes = array();
if ($title !== '') {
$attributes['title'] = $title;
}
if ($item->hidden) {
$attributes['class'] = 'dimmed_text';
}
$content = html_writer::link($item->action, $content, $attributes);
} else if (is_string($item->action) || empty($item->action)) {
$attributes = array();
if ($title !== '') {
$attributes['title'] = $title;
}
if ($item->hidden) {
$attributes['class'] = 'dimmed_text';
}
$content = html_writer::tag('span', $content, $attributes);
}
return $content;
}
}And here’s the call in the page layout general.php:
<?php if ($hascustommenu) { ?>
<div id="custommenu-wrapper">
<div id="custommenu"><?php echo $custommenu; ?></div>
</div>
<?php } ?>That is a lot of work just to add a list-item to the beginning of a list. And as I said, you totally lose all the cool YUI injected classes on the custommenu. One other thing I wanted to do was explore adding a setting to turn the home/cal links on and off and to allow the date to be customized. Frankly I don’t know how (or if it’s even possible) to call a theme setting inside of a renderer.
Anyways, here’s what it looks like now: renderers.php has been deleted! And the call in general.php looks like this now:
<?php if ($hascustommenu) { ?>
<div id="custommenu-wrapper">
<div id="custommenu">
<a class="home" href="<?php echo new moodle_url('/index.php'); ?>">
<div> </div>
</a>
<?php echo $custommenu; ?>
<a class="calendar" href="<?php echo new moodle_url('calendar/view.php'); ?>">
<?php echo date("F j, Y"); ?>
</a>
</div>
</div>
<?php } ?>So now the Home link and calendar link are simply hrefs inside the custommenu div. They’re not list-items any more, but they never really needed to be. And now I have the flexibility to customize their output with settings and have the full power of the YUI custommenu. So the moral of this story is: Just because you can override a core renderer doesn’t mean you should.