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