blocks/moodleblock.class.php

   1 <?php  // $Id$
   2
   3 /**
   4  * This file contains the parent class for moodle blocks, block_base,
   5  * as well as the block_nuke subclass.
   6  *
   7  * @author Jon Papaioannou
   8  * @version  $Id$
   9  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  10  * @package blocks
  11  */
  12
  13 /// Constants
  14
  15 /**
  16  * Block type of list. Contents of block should be set as an associative array in the content object as items ($this->content->items). Optionally include footer text in $this->content->footer.
  17  */
  18 define('BLOCK_TYPE_LIST',    1);
  19
  20 /**
  21  * Block type of text. Contents of block should be set to standard html text in the content object as items ($this->content->text). Optionally include footer text in $this->content->footer.
  22  */
  23 define('BLOCK_TYPE_TEXT',    2);
  24
  25 /**
  26  * Block type of nuke. Compitibility with post nuke blocks. Basically treated as  BLOCK_TYPE_TEXT.
  27  */
  28 define('BLOCK_TYPE_NUKE',    3);
  29
  30 /**
  31  * Class for describing a moodle block, all Moodle blocks derive from this class
  32  *
  33  * @author Jon Papaioannou
  34  * @package blocks
  35  */
  36 class block_base {
  37
  38     /**
  39      * Internal var for storing/caching translated strings
  40      * @var string $str
  41      */
  42     var $str;
  43
  44     /**
  45      * The title of the block to be displayed in the block title area.
  46      * @var string $title
  47      */
  48     var $title         = NULL;
  49
  50     /**
  51      * The type of content that this block creates. Currently support options - BLOCK_TYPE_LIST, BLOCK_TYPE_TEXT, BLOCK_TYPE_NUKE
  52      * @var int $content_type
  53      */
  54     var $content_type  = BLOCK_TYPE_TEXT;
  55
  56     /**
  57      * An object to contain the information to be displayed in the block.
  58      * @var stdObject $content
  59      */
  60     var $content       = NULL;
  61
  62     /**
  63      * A string generated by {@link _add_edit_controls()} to display block manipulation links when the user is in editing mode.
  64      * @var string $edit_controls
  65      */
  66     var $edit_controls = NULL;
  67
  68     /**
  69      * The current version that the block type defines.
  70      * @var string $version
  71      */
  72     var $version       = NULL;
  73
  74     /**
  75      * The initialized instance of this block object.
  76      * @var block $instance
  77      */
  78     var $instance      = NULL;
  79
  80     /**
  81      * An object containing the instance configuration information for the current instance of this block.
  82      * @var stdObject $config
  83      */
  84     var $config        = NULL;
  85
  86     /**
  87      * How often the cronjob should run, 0 if not at all.
  88      * @var int $cron
  89      */
  90
  91     var $cron          = NULL;
  92
  93
  94 /// Class Functions
  95
  96     /**
  97      * The class constructor
  98      *
  99      */
 100     function block_base() {
 101         $this->init();
 102     }
 103
 104     /**
 105      * Fake constructor to keep PHP5 happy
 106      *
 107      */
 108     function __construct() {
 109         $this->block_base();
 110     }
 111
 112     /**
 113      * Returns the block name, as present in the class name,
 114      * the database, the block directory, etc etc.
 115      *
 116      * @return string
 117      */
 118     function name() {
 119         // Returns the block name, as present in the class name,
 120         // the database, the block directory, etc etc.
 121         static $myname;
 122         if ($myname === NULL) {
 123             $myname = strtolower(get_class($this));
 124             $myname = substr($myname, strpos($myname, '_') + 1);
 125         }
 126         return $myname;
 127     }
 128
 129     /**
 130      * Parent class version of this function simply returns NULL
 131      * This should be implemented by the derived class to return
 132      * the content object.
 133      *
 134      * @return stdObject
 135      */
 136     function get_content() {
 137         // This should be implemented by the derived class.
 138         return NULL;
 139     }
 140
 141     /**
 142      * Returns the class $title var value.
 143      *
 144      * Intentionally doesn't check if a title is set.
 145      * This is already done in {@link _self_test()}
 146      *
 147      * @return string $this->title
 148      */
 149     function get_title() {
 150         // Intentionally doesn't check if a title is set. This is already done in _self_test()
 151         return $this->title;
 152     }
 153
 154     /**
 155      * Returns the class $content_type var value.
 156      *
 157      * Intentionally doesn't check if content_type is set.
 158      * This is already done in {@link _self_test()}
 159      *
 160      * @return string $this->content_type
 161      */
 162     function get_content_type() {
 163         // Intentionally doesn't check if a content_type is set. This is already done in _self_test()
 164         return $this->content_type;
 165     }
 166
 167     /**
 168      * Returns the class $version var value.
 169      *
 170      * Intentionally doesn't check if a version is set.
 171      * This is already done in {@link _self_test()}
 172      *
 173      * @return string $this->version
 174      */
 175     function get_version() {
 176         // Intentionally doesn't check if a version is set. This is already done in _self_test()
 177         return $this->version;
 178     }
 179
 180     /**
 181      * Returns true or false, depending on whether this block has any content to display
 182      *
 183      * @return boolean
 184      */
 185     function is_empty() {
 186         $this->get_content();
 187         return(empty($this->content->text) && empty($this->content->footer));
 188     }
 189
 190     /**
 191      * First sets the current value of $this->content to NULL
 192      * then calls the block's {@link get_content()} function
 193      * to set its value back.
 194      *
 195      * @return stdObject
 196      */
 197     function refresh_content() {
 198         // Nothing special here, depends on content()
 199         $this->content = NULL;
 200         return $this->get_content();
 201     }
 202
 203     /**
 204      * Display the block!
 205      */
 206     function _print_block() {
 207         // is_empty() includes a call to get_content()
 208         if ($this->is_empty()) {
 209             if (empty($this->edit_controls)) {
 210                 // No content, no edit controls, so just shut up
 211                 return;
 212             } else {
 213                 // No content but editing, so show something at least
 214                 $this->_print_shadow();
 215             }
 216         } else {
 217             if ($this->hide_header() && empty($this->edit_controls)) {
 218                 // Header wants to hide, no edit controls to show, so no header it is
 219                 print_side_block(NULL, $this->content->text, NULL, NULL, $this->content->footer, $this->html_attributes());
 220             } else {
 221                 // The full treatment, please
 222                 print_side_block($this->_title_html(), $this->content->text, NULL, NULL, $this->content->footer, $this->html_attributes());
 223             }
 224         }
 225     }
 226
 227     /**
 228      * Block contents are missing. Simply display an empty block so that
 229      * edit controls are accessbile to the user and they are aware that this
 230      * block is in place, even if empty.
 231      */
 232     function _print_shadow() {
 233         print_side_block($this->_title_html(), '&nbsp;', NULL, NULL, '', array('class' => 'hidden'));
 234     }
 235
 236
 237     function _title_html() {
 238         global $CFG;
 239
 240         //Accessibility: validation, can't have <div> inside <h2>, use <span>.
 241         $title = '<div class="title">';
 242
 243         if (!empty($CFG->allowuserblockhiding)) {
 244             //Accessibility: added static 'alt' text for the +- icon.
 245             //TODO (nfreear): language string 'hide OR show block'
 246             $title .= '<div class="hide-show"><a title="'.get_string('showhideblock','access').'" href="#" onclick="elementToggleHide(this, true, function(el) {return findParentNode(el, \'DIV\', \'sideblock\'); } ); return false;"><img src="'.$CFG->pixpath.'/spacer.gif" alt="'.get_string('showhideblock','access').'" class="hide-show-image" /></a></div>';
 247         }
 248
 249         //Accesssibility: added H2 (was in, weblib.php: print_side_block)
 250         $title .= '<h2>'.$this->title.'</h2>';
 251
 252         if ($this->edit_controls !== NULL) {
 253             $title .= $this->edit_controls;
 254         }
 255
 256         $title .= '</div>';
 257
 258         return $title;
 259     }
 260
 261     /**
 262      * Sets class $edit_controls var with correct block manipulation links.
 263      *
 264      * @uses $CFG
 265      * @uses $USER
 266      * @param stdObject $options ?
 267      * @todo complete documenting this function. Define $options.
 268      */
 269     function _add_edit_controls($options) {
 270         global $CFG, $USER;
 271
 272         if (!isset($this->str)) {
 273             $this->str->delete    = get_string('delete');
 274             $this->str->moveup    = get_string('moveup');
 275             $this->str->movedown  = get_string('movedown');
 276             $this->str->moveright = get_string('moveright');
 277             $this->str->moveleft  = get_string('moveleft');
 278             $this->str->hide      = get_string('hide');
 279             $this->str->show      = get_string('show');
 280             $this->str->configure = get_string('configuration');
 281         }
 282
 283         $movebuttons = '<div class="commands">';
 284
 285         if ($this->instance->visible) {
 286             $icon = '/t/hide.gif';
 287             $title = $this->str->hide;
 288         } else {
 289             $icon = '/t/show.gif';
 290             $title = $this->str->show;
 291         }
 292
 293         if (empty($this->instance->pageid)) {
 294             $this->instance->pageid = 0;
 295         }
 296         $page   = page_create_object($this->instance->pagetype, $this->instance->pageid);
 297         $script = $page->url_get_full(array('instanceid' => $this->instance->id, 'sesskey' => $USER->sesskey));
 298
 299         $movebuttons .= '<a class="icon hide" title="'. $title .'" href="'.$script.'&amp;blockaction=toggle">' .
 300                         '<img src="'. $CFG->pixpath.$icon .'" alt="'.$title.'" /></a>';
 301
 302         if ($options & BLOCK_CONFIGURE && $this->user_can_edit()) {
 303             $movebuttons .= '<a class="icon edit" title="'. $this->str->configure .'" href="'.$script.'&amp;blockaction=config">' .
 304                             '<img src="'. $CFG->pixpath .'/t/edit.gif" alt="'. $this->str->configure .'" /></a>';
 305         }
 306
 307         $movebuttons .= '<a class="icon delete" title="'. $this->str->delete .'" href="'.$script.'&amp;blockaction=delete">' .
 308                         '<img src="'. $CFG->pixpath .'/t/delete.gif" alt="'. $this->str->delete .'" /></a>';
 309
 310         if ($options & BLOCK_MOVE_LEFT) {
 311             $movebuttons .= '<a class="icon left" title="'. $this->str->moveleft .'" href="'.$script.'&amp;blockaction=moveleft">' .
 312                             '<img src="'. $CFG->pixpath .'/t/left.gif" alt="'. $this->str->moveleft .'" /></a>';
 313         }
 314         if ($options & BLOCK_MOVE_UP) {
 315             $movebuttons .= '<a class="icon up" title="'. $this->str->moveup .'" href="'.$script.'&amp;blockaction=moveup">' .
 316                             '<img src="'. $CFG->pixpath .'/t/up.gif" alt="'. $this->str->moveup .'" /></a>';
 317         }
 318         if ($options & BLOCK_MOVE_DOWN) {
 319             $movebuttons .= '<a class="icon down" title="'. $this->str->movedown .'" href="'.$script.'&amp;blockaction=movedown">' .
 320                             '<img src="'. $CFG->pixpath .'/t/down.gif" alt="'. $this->str->movedown .'" /></a>';
 321         }
 322         if ($options & BLOCK_MOVE_RIGHT) {
 323             $movebuttons .= '<a class="icon right" title="'. $this->str->moveright .'" href="'.$script.'&amp;blockaction=moveright">' .
 324                             '<img src="'. $CFG->pixpath .'/t/right.gif" alt="'. $this->str->moveright .'" /></a>';
 325         }
 326
 327         $movebuttons .= '</div>';
 328         $this->edit_controls = $movebuttons;
 329     }
 330
 331     /**
 332      * Tests if this block has been implemented correctly.
 333      * Also, $errors isn't used right now
 334      *
 335      * @return boolean
 336      */
 337
 338     function _self_test() {
 339         // Tests if this block has been implemented correctly.
 340         // Also, $errors isn't used right now
 341         $errors = array();
 342
 343         $correct = true;
 344         if ($this->get_title() === NULL) {
 345             $errors[] = 'title_not_set';
 346             $correct = false;
 347         }
 348         if (!in_array($this->get_content_type(), array(BLOCK_TYPE_LIST, BLOCK_TYPE_TEXT, BLOCK_TYPE_NUKE))) {
 349             $errors[] = 'invalid_content_type';
 350             $correct = false;
 351         }
 352         if ($this->get_content() === NULL) {
 353             $errors[] = 'content_not_set';
 354             $correct = false;
 355         }
 356         if ($this->get_version() === NULL) {
 357             $errors[] = 'version_not_set';
 358             $correct = false;
 359         }
 360
 361         $formats = $this->applicable_formats();
 362         if (empty($formats) || array_sum($formats) === 0) {
 363             $errors[] = 'no_formats';
 364             $correct = false;
 365         }
 366
 367         $width = $this->preferred_width();
 368         if (!is_int($width) || $width <= 0) {
 369             $errors[] = 'invalid_width';
 370             $correct = false;
 371         }
 372         return $correct;
 373     }
 374
 375     /**
 376      * Subclasses should override this and return true if the
 377      * subclass block has a config_global.html file.
 378      *
 379      * @return boolean
 380      */
 381     function has_config() {
 382         return false;
 383     }
 384
 385     /**
 386      * Default behavior: print the config_global.html file
 387      * You don't need to override this if you're satisfied with the above
 388      *
 389      * @uses $CFG
 390      * @return boolean
 391      */
 392     function config_print() {
 393         // Default behavior: print the config_global.html file
 394         // You don't need to override this if you're satisfied with the above
 395         if (!$this->has_config()) {
 396             return false;
 397         }
 398         global $CFG;
 399         print_simple_box_start('center', '', '', 5, 'blockconfigglobal');
 400         include($CFG->dirroot.'/blocks/'. $this->name() .'/config_global.html');
 401         print_simple_box_end();
 402         return true;
 403     }
 404
 405     /**
 406      * Default behavior: save all variables as $CFG properties
 407      * You don't need to override this if you 're satisfied with the above
 408      *
 409      * @param array $data
 410      * @return boolean
 411      */
 412     function config_save($data) {
 413         foreach ($data as $name => $value) {
 414             set_config($name, $value);
 415         }
 416         return true;
 417     }
 418
 419     /**
 420      * Default case: the block can be used in all course types
 421      * @return array
 422      * @todo finish documenting this function
 423      */
 424     function applicable_formats() {
 425         // Default case: the block can be used in courses and site index, but not in activities
 426         return array('all' => true, 'mod' => false);
 427     }
 428
 429
 430     /**
 431      * Default case: the block wants to be 180 pixels wide
 432      * @return int
 433      */
 434     function preferred_width() {
 435         return 180;
 436     }
 437
 438     /**
 439      * Default return is false - header will be shown
 440      * @return boolean
 441      */
 442     function hide_header() {
 443         return false;
 444     }
 445
 446     /**
 447      * Default case: an id with the instance and a class with our name in it
 448      * @return array
 449      * @todo finish documenting this function
 450      */
 451     function html_attributes() {
 452         return array('id' => 'inst'.$this->instance->id, 'class' => 'block_'. $this->name());
 453     }
 454
 455     /**
 456      * Given an instance set the class var $instance to it and
 457      * load class var $config
 458      * @param block $instance
 459      * @todo add additional documentation to further explain the format of instance and config
 460      */
 461     function _load_instance($instance) {
 462         if (!empty($instance->configdata)) {
 463             $this->config = unserialize(base64_decode($instance->configdata));
 464         }
 465         // [pj] This line below is supposed to be an optimization (we don't need configdata anymore)
 466         // but what it does is break in PHP5 because the same instance object will be passed to
 467         // this function twice in each page view, and the second time it won't have any configdata
 468         // so it won't work correctly. Thus it's commented out.
 469         // unset($instance->configdata);
 470         $this->instance = $instance;
 471         $this->specialization();
 472     }
 473
 474     /**
 475      * This function is called on your subclass right after an instance is loaded
 476      * Use this function to act on instance data just after it's loaded and before anything else is done
 477      * For instance: if your block will have different title's depending on location (site, course, blog, etc)
 478      */
 479     function specialization() {
 480         // Just to make sure that this method exists.
 481     }
 482
 483     /**
 484      * Is each block of this type going to have instance-specific configuration?
 485      * Normally, this setting is controlled by {@link instance_allow_multiple}: if multiple
 486      * instances are allowed, then each will surely need its own configuration. However, in some
 487      * cases it may be necessary to provide instance configuration to blocks that do not want to
 488      * allow multiple instances. In that case, make this function return true.
 489      * I stress again that this makes a difference ONLY if {@link instance_allow_multiple} returns false.
 490      * @return boolean
 491      * @todo finish documenting this function by explaining per-instance configuration further
 492      */
 493     function instance_allow_config() {
 494         return false;
 495     }
 496
 497     /**
 498      * Are you going to allow multiple instances of each block?
 499      * If yes, then it is assumed that the block WILL USE per-instance configuration
 500      * @return boolean
 501      * @todo finish documenting this function by explaining per-instance configuration further
 502      */
 503     function instance_allow_multiple() {
 504         // Are you going to allow multiple instances of each block?
 505         // If yes, then it is assumed that the block WILL USE per-instance configuration
 506         return false;
 507     }
 508
 509     /**
 510      * Default behavior: print the config_instance.html file
 511      * You don't need to override this if you're satisfied with the above
 512      *
 513      * @uses $CFG
 514      * @return boolean
 515      * @todo finish documenting this function
 516      */
 517     function instance_config_print() {
 518         // Default behavior: print the config_instance.html file
 519         // You don't need to override this if you're satisfied with the above
 520         if (!$this->instance_allow_multiple() && !$this->instance_allow_config()) {
 521             return false;
 522         }
 523         global $CFG;
 524
 525         if (is_file($CFG->dirroot .'/blocks/'. $this->name() .'/config_instance.html')) {
 526             print_simple_box_start('center', '', '', 5, 'blockconfiginstance');
 527             include($CFG->dirroot .'/blocks/'. $this->name() .'/config_instance.html');
 528             print_simple_box_end();
 529         } else {
 530             notice(get_string('blockconfigbad'), str_replace('blockaction=', 'dummy=', qualified_me()));
 531         }
 532
 533         return true;
 534     }
 535
 536     /**
 537      * Serialize and store config data
 538      * @return boolean
 539      * @todo finish documenting this function
 540      */
 541     function instance_config_save($data,$pinned=false) {
 542         $data = stripslashes_recursive($data);
 543         $this->config = $data;
 544         $table = 'block_instance';
 545         if (!empty($pinned)) {
 546             $table = 'block_pinned';
 547         }
 548         return set_field($table, 'configdata', base64_encode(serialize($data)), 'id', $this->instance->id);
 549     }
 550
 551     /**
 552      * Replace the instance's configuration data with those currently in $this->config;
 553      * @return boolean
 554      * @todo finish documenting this function
 555      */
 556     function instance_config_commit($pinned=false) {
 557         $table = 'block_instance';
 558         if (!empty($pinned)) {
 559             $table = 'block_pinned';
 560         }
 561         return set_field($table, 'configdata', base64_encode(serialize($this->config)), 'id', $this->instance->id);
 562     }
 563
 564      /**
 565      * Do any additional initialization you may need at the time a new block instance is created
 566      * @return boolean
 567      * @todo finish documenting this function
 568      */
 569     function instance_create() {
 570         return true;
 571     }
 572
 573      /**
 574      * Delete everything related to this instance if you have been using persistent storage other than the configdata field.
 575      * @return boolean
 576      * @todo finish documenting this function
 577      */
 578     function instance_delete() {
 579         return true;
 580     }
 581
 582      /**
 583      * Allows the block class to have a say in the user's ability to edit (i.e., configure) blocks of this type.
 584      * The framework has first say in whether this will be allowed (e.g., no editing allowed unless in edit mode)
 585      * but if the framework does allow it, the block can still decide to refuse.
 586      * @return boolean
 587      * @todo finish documenting this function
 588      */
 589     function user_can_edit() {
 590         return true;
 591     }
 592
 593      /**
 594      * Allows the block class to have a say in the user's ability to create new instances of this block.
 595      * The framework has first say in whether this will be allowed (e.g., no adding allowed unless in edit mode)
 596      * but if the framework does allow it, the block can still decide to refuse.
 597      * This function has access to the complete page object, the creation related to which is being determined.
 598      * @return boolean
 599      * @todo finish documenting this function
 600      */
 601     function user_can_addto(&$page) {
 602         return true;
 603     }
 604
 605 }
 606
 607 /**
 608  * Specialized class for displaying a block with a list of icons/text labels
 609  *
 610  * @author Jon Papaioannou
 611  * @package blocks
 612  */
 613
 614 class block_list extends block_base {
 615     var $content_type  = BLOCK_TYPE_LIST;
 616
 617     function is_empty() {
 618         $this->get_content();
 619         return (empty($this->content->items) && empty($this->content->footer));
 620     }
 621
 622     function _print_block() {
 623         // is_empty() includes a call to get_content()
 624         if ($this->is_empty()) {
 625             if (empty($this->edit_controls)) {
 626                 // No content, no edit controls, so just shut up
 627                 return;
 628             } else {
 629                 // No content but editing, so show something at least
 630                 $this->_print_shadow();
 631             }
 632         } else {
 633             if ($this->hide_header() && empty($this->edit_controls)) {
 634                 // Header wants to hide, no edit controls to show, so no header it is
 635                 print_side_block(NULL, '', $this->content->items, $this->content->icons, $this->content->footer, $this->html_attributes());
 636             } else {
 637                 // The full treatment, please
 638                 print_side_block($this->_title_html(), '', $this->content->items, $this->content->icons, $this->content->footer, $this->html_attributes());
 639             }
 640         }
 641     }
 642
 643 }
 644
 645 /**
 646  * Class for supporting a phpnuke style block as a moodle block
 647  *
 648  * @author Jon Papaioannou
 649  * @package blocks
 650  */
 651 class block_nuke extends block_base {
 652
 653     var $content_type  = BLOCK_TYPE_NUKE;
 654
 655     function get_content() {
 656
 657         if ($this->content !== NULL) {
 658             return $this->content;
 659         }
 660
 661         global $CFG;
 662         $this->content = &New stdClass;
 663
 664         // This whole thing begs to be written for PHP >= 4.3.0 using glob();
 665         $dir = $CFG->dirroot .'/blocks/'. $this->name() .'/nuke/';
 666         if ($dh = @opendir($dir)) {
 667             while (($file = readdir($dh)) !== false) {
 668                 $regs = array();
 669                 if (ereg('^block\-(.*)\.php$', $file, $regs)) {
 670                     // Found it! Let's prepare the environment...
 671
 672                     $oldvals = array();
 673                     if (isset($GLOBALS['admin'])) {
 674                         $oldvals['admin'] = $GLOBALS['admin'];
 675                     }
 676
 677                     $GLOBALS['admin'] = isteacher($this->course->id);
 678                     @include($dir.$file);
 679
 680                     foreach($oldvals as $key => $val) {
 681                         $GLOBALS[$key] = $val;
 682                     }
 683
 684                     // We should have $content set now
 685                     if (!isset($content)) {
 686                         return NULL;
 687                     }
 688                     return $this->content->text = $content;
 689                 }
 690             }
 691         }
 692
 693         // If we reached here, we couldn't find the nuke block for some reason
 694         return $this->content->text = get_string('blockmissingnuke');
 695     }
 696 }
 697
 698 ?>