blocks/navigation/block_navigation.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * This file contains classes used to manage the navigation structures in Moodle
  19  * and was introduced as part of the changes occuring in Moodle 2.0
  20  *
  21  * @since     Moodle 2.0
  22  * @package   block_navigation
  23  * @copyright 2009 Sam Hemelryk
  24  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27 /**
  28  * The global navigation tree block class
  29  *
  30  * Used to produce the global navigation block new to Moodle 2.0
  31  *
  32  * @package   block_navigation
  33  * @category  navigation
  34  * @copyright 2009 Sam Hemelryk
  35  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  36  */
  37 class block_navigation extends block_base {
  38
  39     /** @var int This allows for multiple navigation trees */
  40     public static $navcount;
  41     /** @var string The name of the block */
  42     public $blockname = null;
  43     /** @var bool A switch to indicate whether content has been generated or not. */
  44     protected $contentgenerated = false;
  45     /** @var bool|null variable for checking if the block is docked*/
  46     protected $docked = null;
  47
  48     /** @var int Trim characters from the right */
  49     const TRIM_RIGHT = 1;
  50     /** @var int Trim characters from the left */
  51     const TRIM_LEFT = 2;
  52     /** @var int Trim characters from the center */
  53     const TRIM_CENTER = 3;
  54
  55     /**
  56      * Set the initial properties for the block
  57      */
  58     function init() {
  59         $this->blockname = get_class($this);
  60         $this->title = get_string('pluginname', $this->blockname);
  61     }
  62
  63     /**
  64      * All multiple instances of this block
  65      * @return bool Returns false
  66      */
  67     function instance_allow_multiple() {
  68         return false;
  69     }
  70
  71     /**
  72      * Set the applicable formats for this block to all
  73      * @return array
  74      */
  75     function applicable_formats() {
  76         return array('all' => true);
  77     }
  78
  79     /**
  80      * Allow the user to configure a block instance
  81      * @return bool Returns true
  82      */
  83     function instance_allow_config() {
  84         return true;
  85     }
  86
  87     /**
  88      * The navigation block cannot be hidden by default as it is integral to
  89      * the navigation of Moodle.
  90      *
  91      * @return false
  92      */
  93     function  instance_can_be_hidden() {
  94         return false;
  95     }
  96
  97     /**
  98      * Find out if an instance can be docked.
  99      *
 100      * @return bool true or false depending on whether the instance can be docked or not.
 101      */
 102     function instance_can_be_docked() {
 103         return (parent::instance_can_be_docked() && (empty($this->config->enabledock) || $this->config->enabledock=='yes'));
 104     }
 105
 106     /**
 107      * Gets Javascript that may be required for navigation
 108      */
 109     function get_required_javascript() {
 110         parent::get_required_javascript();
 111         $arguments = array(
 112             'instanceid' => $this->instance->id
 113         );
 114         $this->page->requires->string_for_js('viewallcourses', 'moodle');
 115         $this->page->requires->js_call_amd('block_navigation/navblock', 'init', $arguments);
 116     }
 117
 118     /**
 119      * Gets the content for this block by grabbing it from $this->page
 120      *
 121      * @return object $this->content
 122      */
 123     function get_content() {
 124         global $CFG;
 125         // First check if we have already generated, don't waste cycles
 126         if ($this->contentgenerated === true) {
 127             return $this->content;
 128         }
 129         // JS for navigation moved to the standard theme, the code will probably have to depend on the actual page structure
 130         // $this->page->requires->js('/lib/javascript-navigation.js');
 131         // Navcount is used to allow us to have multiple trees although I dont' know why
 132         // you would want two trees the same
 133
 134         block_navigation::$navcount++;
 135
 136         // Check if this block has been docked
 137         if ($this->docked === null) {
 138             $this->docked = get_user_preferences('nav_in_tab_panel_globalnav'.block_navigation::$navcount, 0);
 139         }
 140
 141         // Check if there is a param to change the docked state
 142         if ($this->docked && optional_param('undock', null, PARAM_INT)==$this->instance->id) {
 143             unset_user_preference('nav_in_tab_panel_globalnav'.block_navigation::$navcount);
 144             $url = $this->page->url;
 145             $url->remove_params(array('undock'));
 146             redirect($url);
 147         } else if (!$this->docked && optional_param('dock', null, PARAM_INT)==$this->instance->id) {
 148             set_user_preferences(array('nav_in_tab_panel_globalnav'.block_navigation::$navcount=>1));
 149             $url = $this->page->url;
 150             $url->remove_params(array('dock'));
 151             redirect($url);
 152         }
 153
 154         $trimmode = self::TRIM_RIGHT;
 155         $trimlength = 50;
 156
 157         if (!empty($this->config->trimmode)) {
 158             $trimmode = (int)$this->config->trimmode;
 159         }
 160
 161         if (!empty($this->config->trimlength)) {
 162             $trimlength = (int)$this->config->trimlength;
 163         }
 164
 165         // Get the navigation object or don't display the block if none provided.
 166         if (!$navigation = $this->get_navigation()) {
 167             return null;
 168         }
 169         $expansionlimit = null;
 170         if (!empty($this->config->expansionlimit)) {
 171             $expansionlimit = $this->config->expansionlimit;
 172             $navigation->set_expansion_limit($this->config->expansionlimit);
 173         }
 174         $this->trim($navigation, $trimmode, $trimlength, ceil($trimlength/2));
 175
 176         // Get the expandable items so we can pass them to JS
 177         $expandable = array();
 178         $navigation->find_expandable($expandable);
 179         if ($expansionlimit) {
 180             foreach ($expandable as $key=>$node) {
 181                 if ($node['type'] > $expansionlimit && !($expansionlimit == navigation_node::TYPE_COURSE && $node['type'] == $expansionlimit && $node['branchid'] == SITEID)) {
 182                     unset($expandable[$key]);
 183                 }
 184             }
 185         }
 186
 187         $limit = 20;
 188         if (!empty($CFG->navcourselimit)) {
 189             $limit = $CFG->navcourselimit;
 190         }
 191         $expansionlimit = 0;
 192         if (!empty($this->config->expansionlimit)) {
 193             $expansionlimit = $this->config->expansionlimit;
 194         }
 195         $arguments = array(
 196             'id'             => $this->instance->id,
 197             'instance'       => $this->instance->id,
 198             'candock'        => $this->instance_can_be_docked(),
 199             'courselimit'    => $limit,
 200             'expansionlimit' => $expansionlimit
 201         );
 202
 203         $options = array();
 204         $options['linkcategories'] = (!empty($this->config->linkcategories) && $this->config->linkcategories == 'yes');
 205
 206         // Grab the items to display
 207         $renderer = $this->page->get_renderer($this->blockname);
 208         $this->content = new stdClass();
 209         $this->content->text = $renderer->navigation_tree($navigation, $expansionlimit, $options);
 210
 211         // Set content generated to true so that we know it has been done
 212         $this->contentgenerated = true;
 213
 214         return $this->content;
 215     }
 216
 217     /**
 218      * Returns the navigation
 219      *
 220      * @return navigation_node The navigation object to display
 221      */
 222     protected function get_navigation() {
 223         // Initialise (only actually happens if it hasn't already been done yet)
 224         $this->page->navigation->initialise();
 225         return clone($this->page->navigation);
 226     }
 227
 228     /**
 229      * Returns the attributes to set for this block
 230      *
 231      * This function returns an array of HTML attributes for this block including
 232      * the defaults.
 233      * {@link block_tree::html_attributes()} is used to get the default arguments
 234      * and then we check whether the user has enabled hover expansion and add the
 235      * appropriate hover class if it has.
 236      *
 237      * @return array An array of HTML attributes
 238      */
 239     public function html_attributes() {
 240         $attributes = parent::html_attributes();
 241         if (!empty($this->config->enablehoverexpansion) && $this->config->enablehoverexpansion == 'yes') {
 242             $attributes['class'] .= ' block_js_expansion';
 243         }
 244         return $attributes;
 245     }
 246
 247     /**
 248      * Trims the text and shorttext properties of this node and optionally
 249      * all of its children.
 250      *
 251      * @param navigation_node $node
 252      * @param int $mode One of navigation_node::TRIM_*
 253      * @param int $long The length to trim text to
 254      * @param int $short The length to trim shorttext to
 255      * @param bool $recurse Recurse all children
 256      */
 257     public function trim(navigation_node $node, $mode=1, $long=50, $short=25, $recurse=true) {
 258         switch ($mode) {
 259             case self::TRIM_RIGHT :
 260                 if (core_text::strlen($node->text)>($long+3)) {
 261                     // Truncate the text to $long characters
 262                     $node->text = $this->trim_right($node->text, $long);
 263                 }
 264                 if (is_string($node->shorttext) && core_text::strlen($node->shorttext)>($short+3)) {
 265                     // Truncate the shorttext
 266                     $node->shorttext = $this->trim_right($node->shorttext, $short);
 267                 }
 268                 break;
 269             case self::TRIM_LEFT :
 270                 if (core_text::strlen($node->text)>($long+3)) {
 271                     // Truncate the text to $long characters
 272                     $node->text = $this->trim_left($node->text, $long);
 273                 }
 274                 if (is_string($node->shorttext) && core_text::strlen($node->shorttext)>($short+3)) {
 275                     // Truncate the shorttext
 276                     $node->shorttext = $this->trim_left($node->shorttext, $short);
 277                 }
 278                 break;
 279             case self::TRIM_CENTER :
 280                 if (core_text::strlen($node->text)>($long+3)) {
 281                     // Truncate the text to $long characters
 282                     $node->text = $this->trim_center($node->text, $long);
 283                 }
 284                 if (is_string($node->shorttext) && core_text::strlen($node->shorttext)>($short+3)) {
 285                     // Truncate the shorttext
 286                     $node->shorttext = $this->trim_center($node->shorttext, $short);
 287                 }
 288                 break;
 289         }
 290         if ($recurse && $node->children->count()) {
 291             foreach ($node->children as &$child) {
 292                 $this->trim($child, $mode, $long, $short, true);
 293             }
 294         }
 295     }
 296     /**
 297      * Truncate a string from the left
 298      * @param string $string The string to truncate
 299      * @param int $length The length to truncate to
 300      * @return string The truncated string
 301      */
 302     protected function trim_left($string, $length) {
 303         return '...'.core_text::substr($string, core_text::strlen($string)-$length, $length);
 304     }
 305     /**
 306      * Truncate a string from the right
 307      * @param string $string The string to truncate
 308      * @param int $length The length to truncate to
 309      * @return string The truncated string
 310      */
 311     protected function trim_right($string, $length) {
 312         return core_text::substr($string, 0, $length).'...';
 313     }
 314     /**
 315      * Truncate a string in the center
 316      * @param string $string The string to truncate
 317      * @param int $length The length to truncate to
 318      * @return string The truncated string
 319      */
 320     protected function trim_center($string, $length) {
 321         $trimlength = ceil($length/2);
 322         $start = core_text::substr($string, 0, $trimlength);
 323         $end = core_text::substr($string, core_text::strlen($string)-$trimlength);
 324         $string = $start.'...'.$end;
 325         return $string;
 326     }
 327
 328     /**
 329      * Returns the role that best describes the navigation block... 'navigation'
 330      *
 331      * @return string 'navigation'
 332      */
 333     public function get_aria_role() {
 334         return 'navigation';
 335     }
 336 }