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     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         global $CFG;
 111         parent::get_required_javascript();
 112         $limit = 20;
 113         if (!empty($CFG->navcourselimit)) {
 114             $limit = $CFG->navcourselimit;
 115         }
 116         $expansionlimit = 0;
 117         if (!empty($this->config->expansionlimit)) {
 118             $expansionlimit = $this->config->expansionlimit;
 119         }
 120         $arguments = array(
 121             'id'             => $this->instance->id,
 122             'instance'       => $this->instance->id,
 123             'candock'        => $this->instance_can_be_docked(),
 124             'courselimit'    => $limit,
 125             'expansionlimit' => $expansionlimit
 126         );
 127         $this->page->requires->string_for_js('viewallcourses', 'moodle');
 128         $this->page->requires->yui_module('moodle-block_navigation-navigation', 'M.block_navigation.init_add_tree', array($arguments));
 129     }
 130
 131     /**
 132      * Gets the content for this block by grabbing it from $this->page
 133      *
 134      * @return object $this->content
 135      */
 136     function get_content() {
 137         // First check if we have already generated, don't waste cycles
 138         if ($this->contentgenerated === true) {
 139             return $this->content;
 140         }
 141         // JS for navigation moved to the standard theme, the code will probably have to depend on the actual page structure
 142         // $this->page->requires->js('/lib/javascript-navigation.js');
 143         // Navcount is used to allow us to have multiple trees although I dont' know why
 144         // you would want two trees the same
 145
 146         block_navigation::$navcount++;
 147
 148         // Check if this block has been docked
 149         if ($this->docked === null) {
 150             $this->docked = get_user_preferences('nav_in_tab_panel_globalnav'.block_navigation::$navcount, 0);
 151         }
 152
 153         // Check if there is a param to change the docked state
 154         if ($this->docked && optional_param('undock', null, PARAM_INT)==$this->instance->id) {
 155             unset_user_preference('nav_in_tab_panel_globalnav'.block_navigation::$navcount);
 156             $url = $this->page->url;
 157             $url->remove_params(array('undock'));
 158             redirect($url);
 159         } else if (!$this->docked && optional_param('dock', null, PARAM_INT)==$this->instance->id) {
 160             set_user_preferences(array('nav_in_tab_panel_globalnav'.block_navigation::$navcount=>1));
 161             $url = $this->page->url;
 162             $url->remove_params(array('dock'));
 163             redirect($url);
 164         }
 165
 166         $trimmode = self::TRIM_LEFT;
 167         $trimlength = 50;
 168
 169         if (!empty($this->config->trimmode)) {
 170             $trimmode = (int)$this->config->trimmode;
 171         }
 172
 173         if (!empty($this->config->trimlength)) {
 174             $trimlength = (int)$this->config->trimlength;
 175         }
 176
 177         // Get the navigation object or don't display the block if none provided.
 178         if (!$navigation = $this->get_navigation()) {
 179             return null;
 180         }
 181         $expansionlimit = null;
 182         if (!empty($this->config->expansionlimit)) {
 183             $expansionlimit = $this->config->expansionlimit;
 184             $navigation->set_expansion_limit($this->config->expansionlimit);
 185         }
 186         $this->trim($navigation, $trimmode, $trimlength, ceil($trimlength/2));
 187
 188         // Get the expandable items so we can pass them to JS
 189         $expandable = array();
 190         $navigation->find_expandable($expandable);
 191         if ($expansionlimit) {
 192             foreach ($expandable as $key=>$node) {
 193                 if ($node['type'] > $expansionlimit && !($expansionlimit == navigation_node::TYPE_COURSE && $node['type'] == $expansionlimit && $node['branchid'] == SITEID)) {
 194                     unset($expandable[$key]);
 195                 }
 196             }
 197         }
 198
 199         $this->page->requires->data_for_js('navtreeexpansions'.$this->instance->id, $expandable);
 200
 201         $options = array();
 202         $options['linkcategories'] = (!empty($this->config->linkcategories) && $this->config->linkcategories == 'yes');
 203
 204         // Grab the items to display
 205         $renderer = $this->page->get_renderer($this->blockname);
 206         $this->content = new stdClass();
 207         $this->content->text = $renderer->navigation_tree($navigation, $expansionlimit, $options);
 208
 209         // Set content generated to true so that we know it has been done
 210         $this->contentgenerated = true;
 211
 212         return $this->content;
 213     }
 214
 215     /**
 216      * Returns the navigation
 217      *
 218      * @return navigation_node The navigation object to display
 219      */
 220     protected function get_navigation() {
 221         // Initialise (only actually happens if it hasn't already been done yet)
 222         $this->page->navigation->initialise();
 223         return clone($this->page->navigation);
 224     }
 225
 226     /**
 227      * Returns the attributes to set for this block
 228      *
 229      * This function returns an array of HTML attributes for this block including
 230      * the defaults.
 231      * {@link block_tree::html_attributes()} is used to get the default arguments
 232      * and then we check whether the user has enabled hover expansion and add the
 233      * appropriate hover class if it has.
 234      *
 235      * @return array An array of HTML attributes
 236      */
 237     public function html_attributes() {
 238         $attributes = parent::html_attributes();
 239         if (!empty($this->config->enablehoverexpansion) && $this->config->enablehoverexpansion == 'yes') {
 240             $attributes['class'] .= ' block_js_expansion';
 241         }
 242         return $attributes;
 243     }
 244
 245     /**
 246      * Trims the text and shorttext properties of this node and optionally
 247      * all of its children.
 248      *
 249      * @param navigation_node $node
 250      * @param int $mode One of navigation_node::TRIM_*
 251      * @param int $long The length to trim text to
 252      * @param int $short The length to trim shorttext to
 253      * @param bool $recurse Recurse all children
 254      */
 255     public function trim(navigation_node $node, $mode=1, $long=50, $short=25, $recurse=true) {
 256         switch ($mode) {
 257             case self::TRIM_RIGHT :
 258                 if (core_text::strlen($node->text)>($long+3)) {
 259                     // Truncate the text to $long characters
 260                     $node->text = $this->trim_right($node->text, $long);
 261                 }
 262                 if (is_string($node->shorttext) && core_text::strlen($node->shorttext)>($short+3)) {
 263                     // Truncate the shorttext
 264                     $node->shorttext = $this->trim_right($node->shorttext, $short);
 265                 }
 266                 break;
 267             case self::TRIM_LEFT :
 268                 if (core_text::strlen($node->text)>($long+3)) {
 269                     // Truncate the text to $long characters
 270                     $node->text = $this->trim_left($node->text, $long);
 271                 }
 272                 if (is_string($node->shorttext) && core_text::strlen($node->shorttext)>($short+3)) {
 273                     // Truncate the shorttext
 274                     $node->shorttext = $this->trim_left($node->shorttext, $short);
 275                 }
 276                 break;
 277             case self::TRIM_CENTER :
 278                 if (core_text::strlen($node->text)>($long+3)) {
 279                     // Truncate the text to $long characters
 280                     $node->text = $this->trim_center($node->text, $long);
 281                 }
 282                 if (is_string($node->shorttext) && core_text::strlen($node->shorttext)>($short+3)) {
 283                     // Truncate the shorttext
 284                     $node->shorttext = $this->trim_center($node->shorttext, $short);
 285                 }
 286                 break;
 287         }
 288         if ($recurse && $node->children->count()) {
 289             foreach ($node->children as &$child) {
 290                 $this->trim($child, $mode, $long, $short, true);
 291             }
 292         }
 293     }
 294     /**
 295      * Truncate a string from the left
 296      * @param string $string The string to truncate
 297      * @param int $length The length to truncate to
 298      * @return string The truncated string
 299      */
 300     protected function trim_left($string, $length) {
 301         return '...'.core_text::substr($string, core_text::strlen($string)-$length, $length);
 302     }
 303     /**
 304      * Truncate a string from the right
 305      * @param string $string The string to truncate
 306      * @param int $length The length to truncate to
 307      * @return string The truncated string
 308      */
 309     protected function trim_right($string, $length) {
 310         return core_text::substr($string, 0, $length).'...';
 311     }
 312     /**
 313      * Truncate a string in the center
 314      * @param string $string The string to truncate
 315      * @param int $length The length to truncate to
 316      * @return string The truncated string
 317      */
 318     protected function trim_center($string, $length) {
 319         $trimlength = ceil($length/2);
 320         $start = core_text::substr($string, 0, $trimlength);
 321         $end = core_text::substr($string, core_text::strlen($string)-$trimlength);
 322         $string = $start.'...'.$end;
 323         return $string;
 324     }
 325
 326     /**
 327      * Returns the role that best describes the navigation block... 'navigation'
 328      *
 329      * @return string 'navigation'
 330      */
 331     public function get_aria_role() {
 332         return 'navigation';
 333     }
 334 }