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   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  }