course/dnduploadlib.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  * Library to handle drag and drop course uploads
  19  *
  20  * @package    core
  21  * @subpackage lib
  22  * @copyright  2012 Davo smith
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 defined('MOODLE_INTERNAL') || die();
  27
  28 require_once($CFG->dirroot.'/repository/lib.php');
  29 require_once($CFG->dirroot.'/repository/upload/lib.php');
  30 require_once($CFG->dirroot.'/course/lib.php');
  31
  32 /**
  33  * Add the Javascript to enable drag and drop upload to a course page
  34  *
  35  * @param object $course The currently displayed course
  36  * @param array $modnames The list of enabled (visible) modules on this site
  37  * @return void
  38  */
  39 function dndupload_add_to_course($course, $modnames) {
  40     global $CFG, $PAGE;
  41
  42     $showstatus = optional_param('notifyeditingon', false, PARAM_BOOL);
  43
  44     // Get all handlers.
  45     $handler = new dndupload_handler($course, $modnames);
  46     $jsdata = $handler->get_js_data();
  47     if (empty($jsdata->types) && empty($jsdata->filehandlers)) {
  48         return; // No valid handlers - don't enable drag and drop.
  49     }
  50
  51     // Add the javascript to the page.
  52     $jsmodule = array(
  53         'name' => 'coursedndupload',
  54         'fullpath' => '/course/dndupload.js',
  55         'strings' => array(
  56             array('addfilehere', 'moodle'),
  57             array('dndworkingfiletextlink', 'moodle'),
  58             array('dndworkingfilelink', 'moodle'),
  59             array('dndworkingfiletext', 'moodle'),
  60             array('dndworkingfile', 'moodle'),
  61             array('dndworkingtextlink', 'moodle'),
  62             array('dndworkingtext', 'moodle'),
  63             array('dndworkinglink', 'moodle'),
  64             array('filetoolarge', 'moodle'),
  65             array('actionchoice', 'moodle'),
  66             array('servererror', 'moodle'),
  67             array('upload', 'moodle'),
  68             array('cancel', 'moodle')
  69         ),
  70         'requires' => array('node', 'event', 'json', 'anim')
  71     );
  72     $vars = array(
  73         array('courseid' => $course->id,
  74               'maxbytes' => get_max_upload_file_size($CFG->maxbytes, $course->maxbytes),
  75               'handlers' => $handler->get_js_data(),
  76               'showstatus' => $showstatus)
  77     );
  78
  79     $PAGE->requires->js_init_call('M.course_dndupload.init', $vars, true, $jsmodule);
  80 }
  81
  82
  83 /**
  84  * Stores all the information about the available dndupload handlers
  85  *
  86  * @package    core
  87  * @copyright  2012 Davo Smith
  88  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  89  */
  90 class dndupload_handler {
  91
  92     /**
  93      * @var array A list of all registered mime types that can be dropped onto a course
  94      *            along with the modules that will handle them.
  95      */
  96     protected $types = array();
  97
  98     /**
  99      * @var array  A list of the different file types (extensions) that different modules
 100      *             will handle.
 101      */
 102     protected $filehandlers = array();
 103
 104     /**
 105      * @var context_course|null
 106      */
 107     protected $context = null;
 108
 109     /**
 110      * Gather a list of dndupload handlers from the different mods
 111      *
 112      * @param object $course The course this is being added to (to check course_allowed_module() )
 113      */
 114     public function __construct($course, $modnames = null) {
 115         global $CFG, $PAGE;
 116
 117         // Add some default types to handle.
 118         // Note: 'Files' type is hard-coded into the Javascript as this needs to be ...
 119         // ... treated a little differently.
 120         $this->register_type('url', array('url', 'text/uri-list', 'text/x-moz-url'), get_string('addlinkhere', 'moodle'),
 121                         get_string('nameforlink', 'moodle'), get_string('whatforlink', 'moodle'), 10);
 122         $this->register_type('text/html', array('text/html'), get_string('addpagehere', 'moodle'),
 123                         get_string('nameforpage', 'moodle'), get_string('whatforpage', 'moodle'), 20);
 124         $this->register_type('text', array('text', 'text/plain'), get_string('addpagehere', 'moodle'),
 125                         get_string('nameforpage', 'moodle'), get_string('whatforpage', 'moodle'), 30);
 126
 127         $this->context = context_course::instance($course->id);
 128
 129         // Loop through all modules to find handlers.
 130         $mods = get_plugin_list_with_function('mod', 'dndupload_register');
 131         foreach ($mods as $component => $funcname) {
 132             list($modtype, $modname) = core_component::normalize_component($component);
 133             if ($modnames && !array_key_exists($modname, $modnames)) {
 134                 continue; // Module is deactivated (hidden) at the site level.
 135             }
 136             if (!course_allowed_module($course, $modname)) {
 137                 continue; // User does not have permission to add this module to the course.
 138             }
 139             $resp = $funcname();
 140             if (!$resp) {
 141                 continue;
 142             }
 143             if (isset($resp['files'])) {
 144                 foreach ($resp['files'] as $file) {
 145                     $this->register_file_handler($file['extension'], $modname, $file['message']);
 146                 }
 147             }
 148             if (isset($resp['addtypes'])) {
 149                 foreach ($resp['addtypes'] as $type) {
 150                     if (isset($type['priority'])) {
 151                         $priority = $type['priority'];
 152                     } else {
 153                         $priority = 100;
 154                     }
 155                     if (!isset($type['handlermessage'])) {
 156                         $type['handlermessage'] = '';
 157                     }
 158                     $this->register_type($type['identifier'], $type['datatransfertypes'],
 159                                     $type['addmessage'], $type['namemessage'], $type['handlermessage'], $priority);
 160                 }
 161             }
 162             if (isset($resp['types'])) {
 163                 foreach ($resp['types'] as $type) {
 164                     $noname = !empty($type['noname']);
 165                     $this->register_type_handler($type['identifier'], $modname, $type['message'], $noname);
 166                 }
 167             }
 168             $PAGE->requires->string_for_js('pluginname', $modname);
 169         }
 170     }
 171
 172     /**
 173      * Used to add a new mime type that can be drag and dropped onto a
 174      * course displayed in a browser window
 175      *
 176      * @param string $identifier The name that this type will be known as
 177      * @param array $datatransfertypes An array of the different types in the browser
 178      *                                 'dataTransfer.types' object that will map to this type
 179      * @param string $addmessage The message to display in the browser when this type is being
 180      *                           dragged onto the page
 181      * @param string $namemessage The message to pop up when asking for the name to give the
 182      *                            course module instance when it is created
 183      * @param string $handlermessage The message to pop up when asking which module should handle this type
 184      * @param int $priority Controls the order in which types are checked by the browser (mainly
 185      *                      needed to check for 'text' last as that is usually given as fallback)
 186      */
 187     protected function register_type($identifier, $datatransfertypes, $addmessage, $namemessage, $handlermessage, $priority=100) {
 188         if ($this->is_known_type($identifier)) {
 189             throw new coding_exception("Type $identifier is already registered");
 190         }
 191
 192         $add = new stdClass;
 193         $add->identifier = $identifier;
 194         $add->datatransfertypes = $datatransfertypes;
 195         $add->addmessage = $addmessage;
 196         $add->namemessage = $namemessage;
 197         $add->handlermessage = $handlermessage;
 198         $add->priority = $priority;
 199         $add->handlers = array();
 200
 201         $this->types[$identifier] = $add;
 202     }
 203
 204     /**
 205      * Used to declare that a particular module will handle a particular type
 206      * of dropped data
 207      *
 208      * @param string $type The name of the type (as declared in register_type)
 209      * @param string $module The name of the module to handle this type
 210      * @param string $message The message to show the user if more than one handler is registered
 211      *                        for a type and the user needs to make a choice between them
 212      * @param bool $noname If true, the 'name' dialog should be disabled in the pop-up.
 213      * @throws coding_exception
 214      */
 215     protected function register_type_handler($type, $module, $message, $noname) {
 216         if (!$this->is_known_type($type)) {
 217             throw new coding_exception("Trying to add handler for unknown type $type");
 218         }
 219
 220         $add = new stdClass;
 221         $add->type = $type;
 222         $add->module = $module;
 223         $add->message = $message;
 224         $add->noname = $noname ? 1 : 0;
 225
 226         $this->types[$type]->handlers[] = $add;
 227     }
 228
 229     /**
 230      * Used to declare that a particular module will handle a particular type
 231      * of dropped file
 232      *
 233      * @param string $extension The file extension to handle ('*' for all types)
 234      * @param string $module The name of the module to handle this type
 235      * @param string $message The message to show the user if more than one handler is registered
 236      *                        for a type and the user needs to make a choice between them
 237      */
 238     protected function register_file_handler($extension, $module, $message) {
 239         $extension = strtolower($extension);
 240
 241         $add = new stdClass;
 242         $add->extension = $extension;
 243         $add->module = $module;
 244         $add->message = $message;
 245
 246         $this->filehandlers[] = $add;
 247     }
 248
 249     /**
 250      * Check to see if the type has been registered
 251      *
 252      * @param string $type The identifier of the type you are interested in
 253      * @return bool True if the type is registered
 254      */
 255     public function is_known_type($type) {
 256         return array_key_exists($type, $this->types);
 257     }
 258
 259     /**
 260      * Check to see if the module in question has registered to handle the
 261      * type given
 262      *
 263      * @param string $module The name of the module
 264      * @param string $type The identifier of the type
 265      * @return bool True if the module has registered to handle that type
 266      */
 267     public function has_type_handler($module, $type) {
 268         if (!$this->is_known_type($type)) {
 269             throw new coding_exception("Checking for handler for unknown type $type");
 270         }
 271         foreach ($this->types[$type]->handlers as $handler) {
 272             if ($handler->module == $module) {
 273                 return true;
 274             }
 275         }
 276         return false;
 277     }
 278
 279     /**
 280      * Check to see if the module in question has registered to handle files
 281      * with the given extension (or to handle all file types)
 282      *
 283      * @param string $module The name of the module
 284      * @param string $extension The extension of the uploaded file
 285      * @return bool True if the module has registered to handle files with
 286      *              that extension (or to handle all file types)
 287      */
 288     public function has_file_handler($module, $extension) {
 289         foreach ($this->filehandlers as $handler) {
 290             if ($handler->module == $module) {
 291                 if ($handler->extension == '*' || $handler->extension == $extension) {
 292                     return true;
 293                 }
 294             }
 295         }
 296         return false;
 297     }
 298
 299     /**
 300      * Gets a list of the file types that are handled by a particular module
 301      *
 302      * @param string $module The name of the module to check
 303      * @return array of file extensions or string '*'
 304      */
 305     public function get_handled_file_types($module) {
 306         $types = array();
 307         foreach ($this->filehandlers as $handler) {
 308             if ($handler->module == $module) {
 309                 if ($handler->extension == '*') {
 310                     return '*';
 311                 } else {
 312                     // Prepending '.' as otherwise mimeinfo fails.
 313                     $types[] = '.'.$handler->extension;
 314                 }
 315             }
 316         }
 317         return $types;
 318     }
 319
 320     /**
 321      * Returns an object to pass onto the javascript code with data about all the
 322      * registered file / type handlers
 323      *
 324      * @return object Data to pass on to Javascript code
 325      */
 326     public function get_js_data() {
 327         global $CFG;
 328
 329         $ret = new stdClass;
 330
 331         // Sort the types by priority.
 332         uasort($this->types, array($this, 'type_compare'));
 333
 334         $ret->types = array();
 335         if (!empty($CFG->dndallowtextandlinks)) {
 336             foreach ($this->types as $type) {
 337                 if (empty($type->handlers)) {
 338                     continue; // Skip any types without registered handlers.
 339                 }
 340                 $ret->types[] = $type;
 341             }
 342         }
 343
 344         $ret->filehandlers = $this->filehandlers;
 345         $uploadrepo = repository::get_instances(array('type' => 'upload', 'currentcontext' => $this->context));
 346         if (empty($uploadrepo)) {
 347             $ret->filehandlers = array(); // No upload repo => no file handlers.
 348         }
 349
 350         return $ret;
 351     }
 352
 353     /**
 354      * Comparison function used when sorting types by priority
 355      * @param object $type1 first type to compare
 356      * @param object $type2 second type to compare
 357      * @return integer -1 for $type1 < $type2; 1 for $type1 > $type2; 0 for equal
 358      */
 359     protected function type_compare($type1, $type2) {
 360         if ($type1->priority < $type2->priority) {
 361             return -1;
 362         }
 363         if ($type1->priority > $type2->priority) {
 364             return 1;
 365         }
 366         return 0;
 367     }
 368
 369 }
 370
 371 /**
 372  * Processes the upload, creating the course module and returning the result
 373  *
 374  * @package    core
 375  * @copyright  2012 Davo Smith
 376  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 377  */
 378 class dndupload_ajax_processor {
 379
 380     /** Returned when no error has occurred */
 381     const ERROR_OK = 0;
 382
 383     /** @var object The course that we are uploading to */
 384     protected $course = null;
 385
 386     /** @var context_course The course context for capability checking */
 387     protected $context = null;
 388
 389     /** @var int The section number we are uploading to */
 390     protected $section = null;
 391
 392     /** @var string The type of upload (e.g. 'Files', 'text/plain') */
 393     protected $type = null;
 394
 395     /** @var object The details of the module type that will be created */
 396     protected $module= null;
 397
 398     /** @var object The course module that has been created */
 399     protected $cm = null;
 400
 401     /** @var dndupload_handler used to check the allowed file types */
 402     protected $dnduploadhandler = null;
 403
 404     /** @var string The name to give the new activity instance */
 405     protected $displayname = null;
 406
 407     /**
 408      * Set up some basic information needed to handle the upload
 409      *
 410      * @param int $courseid The ID of the course we are uploading to
 411      * @param int $section The section number we are uploading to
 412      * @param string $type The type of upload (as reported by the browser)
 413      * @param string $modulename The name of the module requested to handle this upload
 414      */
 415     public function __construct($courseid, $section, $type, $modulename) {
 416         global $DB;
 417
 418         if (!defined('AJAX_SCRIPT')) {
 419             throw new coding_exception('dndupload_ajax_processor should only be used within AJAX requests');
 420         }
 421
 422         $this->course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
 423
 424         require_login($this->course, false);
 425         $this->context = context_course::instance($this->course->id);
 426
 427         if (!is_number($section) || $section < 0) {
 428             throw new coding_exception("Invalid section number $section");
 429         }
 430         $this->section = $section;
 431         $this->type = $type;
 432
 433         if (!$this->module = $DB->get_record('modules', array('name' => $modulename))) {
 434             throw new coding_exception("Module $modulename does not exist");
 435         }
 436
 437         $this->dnduploadhandler = new dndupload_handler($this->course);
 438     }
 439
 440     /**
 441      * Check if this upload is a 'file' upload
 442      *
 443      * @return bool true if it is a 'file' upload, false otherwise
 444      */
 445     protected function is_file_upload() {
 446         return ($this->type == 'Files');
 447     }
 448
 449     /**
 450      * Process the upload - creating the module in the course and returning the result to the browser
 451      *
 452      * @param string $displayname optional the name (from the browser) to give the course module instance
 453      * @param string $content optional the content of the upload (for non-file uploads)
 454      */
 455     public function process($displayname = null, $content = null) {
 456         require_capability('moodle/course:manageactivities', $this->context);
 457
 458         if ($this->is_file_upload()) {
 459             require_capability('moodle/course:managefiles', $this->context);
 460             if ($content != null) {
 461                 throw new moodle_exception('fileuploadwithcontent', 'moodle');
 462             }
 463         } else {
 464             if (empty($content)) {
 465                 throw new moodle_exception('dnduploadwithoutcontent', 'moodle');
 466             }
 467         }
 468
 469         require_sesskey();
 470
 471         $this->displayname = $displayname;
 472
 473         if ($this->is_file_upload()) {
 474             $this->handle_file_upload();
 475         } else {
 476             $this->handle_other_upload($content);
 477         }
 478     }
 479
 480     /**
 481      * Handle uploads containing files - create the course module, ask the upload repository
 482      * to process the file, ask the mod to set itself up, then return the result to the browser
 483      */
 484     protected function handle_file_upload() {
 485         global $CFG;
 486
 487         // Add the file to a draft file area.
 488         $draftitemid = file_get_unused_draft_itemid();
 489         $maxbytes = get_max_upload_file_size($CFG->maxbytes, $this->course->maxbytes);
 490         $types = $this->dnduploadhandler->get_handled_file_types($this->module->name);
 491         $repo = repository::get_instances(array('type' => 'upload', 'currentcontext' => $this->context));
 492         if (empty($repo)) {
 493             throw new moodle_exception('errornouploadrepo', 'moodle');
 494         }
 495         $repo = reset($repo); // Get the first (and only) upload repo.
 496         $details = $repo->process_upload(null, $maxbytes, $types, '/', $draftitemid);
 497         if (empty($this->displayname)) {
 498             $this->displayname = $this->display_name_from_file($details['file']);
 499         }
 500
 501         // Create a course module to hold the new instance.
 502         $this->create_course_module();
 503
 504         // Ask the module to set itself up.
 505         $moduledata = $this->prepare_module_data($draftitemid);
 506         $instanceid = plugin_callback('mod', $this->module->name, 'dndupload', 'handle', array($moduledata), 'invalidfunction');
 507         if ($instanceid === 'invalidfunction') {
 508             throw new coding_exception("{$this->module->name} does not support drag and drop upload (missing {$this->module->name}_dndupload_handle function");
 509         }
 510
 511         // Finish setting up the course module.
 512         $this->finish_setup_course_module($instanceid);
 513     }
 514
 515     /**
 516      * Handle uploads not containing file - create the course module, ask the mod to
 517      * set itself up, then return the result to the browser
 518      *
 519      * @param string $content the content uploaded to the browser
 520      */
 521     protected function handle_other_upload($content) {
 522         // Check this plugin is registered to handle this type of upload
 523         if (!$this->dnduploadhandler->has_type_handler($this->module->name, $this->type)) {
 524             $info = (object)array('modname' => $this->module->name, 'type' => $this->type);
 525             throw new moodle_exception('moddoesnotsupporttype', 'moodle', $info);
 526         }
 527
 528         // Create a course module to hold the new instance.
 529         $this->create_course_module();
 530
 531         // Ask the module to set itself up.
 532         $moduledata = $this->prepare_module_data(null, $content);
 533         $instanceid = plugin_callback('mod', $this->module->name, 'dndupload', 'handle', array($moduledata), 'invalidfunction');
 534         if ($instanceid === 'invalidfunction') {
 535             throw new coding_exception("{$this->module->name} does not support drag and drop upload (missing {$this->module->name}_dndupload_handle function");
 536         }
 537
 538         // Finish setting up the course module.
 539         $this->finish_setup_course_module($instanceid);
 540     }
 541
 542     /**
 543      * Generate the name of the mod instance from the name of the file
 544      * (remove the extension and convert underscore => space
 545      *
 546      * @param string $filename the filename of the uploaded file
 547      * @return string the display name to use
 548      */
 549     protected function display_name_from_file($filename) {
 550         $pos = core_text::strrpos($filename, '.');
 551         if ($pos) { // Want to skip if $pos === 0 OR $pos === false.
 552             $filename = core_text::substr($filename, 0, $pos);
 553         }
 554         return str_replace('_', ' ', $filename);
 555     }
 556
 557     /**
 558      * Create the coursemodule to hold the file/content that has been uploaded
 559      */
 560     protected function create_course_module() {
 561         global $CFG;
 562
 563         if (!course_allowed_module($this->course, $this->module->name)) {
 564             throw new coding_exception("The module {$this->module->name} is not allowed to be added to this course");
 565         }
 566
 567         $this->cm = new stdClass();
 568         $this->cm->course = $this->course->id;
 569         $this->cm->section = $this->section;
 570         $this->cm->module = $this->module->id;
 571         $this->cm->modulename = $this->module->name;
 572         $this->cm->instance = 0; // This will be filled in after we create the instance.
 573         $this->cm->visible = 1;
 574         $this->cm->groupmode = $this->course->groupmode;
 575         $this->cm->groupingid = $this->course->defaultgroupingid;
 576
 577         // Set the correct default for completion tracking.
 578         $this->cm->completion = COMPLETION_TRACKING_NONE;
 579         $completion = new completion_info($this->course);
 580         if ($completion->is_enabled() && $CFG->completiondefault) {
 581             if (plugin_supports('mod', $this->cm->modulename, FEATURE_MODEDIT_DEFAULT_COMPLETION, true)) {
 582                 $this->cm->completion = COMPLETION_TRACKING_MANUAL;
 583             }
 584         }
 585
 586         if (!$this->cm->id = add_course_module($this->cm)) {
 587             throw new coding_exception("Unable to create the course module");
 588         }
 589         $this->cm->coursemodule = $this->cm->id;
 590     }
 591
 592     /**
 593      * Gather together all the details to pass on to the mod, so that it can initialise it's
 594      * own database tables
 595      *
 596      * @param int $draftitemid optional the id of the draft area containing the file (for file uploads)
 597      * @param string $content optional the content dropped onto the course (for non-file uploads)
 598      * @return object data to pass on to the mod, containing:
 599      *              string $type the 'type' as registered with dndupload_handler (or 'Files')
 600      *              object $course the course the upload was for
 601      *              int $draftitemid optional the id of the draft area containing the files
 602      *              int $coursemodule id of the course module that has already been created
 603      *              string $displayname the name to use for this activity (can be overriden by the mod)
 604      */
 605     protected function prepare_module_data($draftitemid = null, $content = null) {
 606         $data = new stdClass();
 607         $data->type = $this->type;
 608         $data->course = $this->course;
 609         if ($draftitemid) {
 610             $data->draftitemid = $draftitemid;
 611         } else if ($content) {
 612             $data->content = $content;
 613         }
 614         $data->coursemodule = $this->cm->id;
 615         $data->displayname = $this->displayname;
 616         return $data;
 617     }
 618
 619     /**
 620      * Called after the mod has set itself up, to finish off any course module settings
 621      * (set instance id, add to correct section, set visibility, etc.) and send the response
 622      *
 623      * @param int $instanceid id returned by the mod when it was created
 624      */
 625     protected function finish_setup_course_module($instanceid) {
 626         global $DB, $USER;
 627
 628         if (!$instanceid) {
 629             // Something has gone wrong - undo everything we can.
 630             course_delete_module($this->cm->id);
 631             throw new moodle_exception('errorcreatingactivity', 'moodle', '', $this->module->name);
 632         }
 633
 634         // Note the section visibility
 635         $visible = get_fast_modinfo($this->course)->get_section_info($this->section)->visible;
 636
 637         $DB->set_field('course_modules', 'instance', $instanceid, array('id' => $this->cm->id));
 638         // Rebuild the course cache after update action
 639         rebuild_course_cache($this->course->id, true);
 640
 641         $sectionid = course_add_cm_to_section($this->course, $this->cm->id, $this->section);
 642
 643         set_coursemodule_visible($this->cm->id, $visible);
 644         if (!$visible) {
 645             $DB->set_field('course_modules', 'visibleold', 1, array('id' => $this->cm->id));
 646         }
 647
 648         // retrieve the final info about this module.
 649         $info = get_fast_modinfo($this->course);
 650         if (!isset($info->cms[$this->cm->id])) {
 651             // The course module has not been properly created in the course - undo everything.
 652             course_delete_module($this->cm->id);
 653             throw new moodle_exception('errorcreatingactivity', 'moodle', '', $this->module->name);
 654         }
 655         $mod = $info->get_cm($this->cm->id);
 656
 657         // Trigger course module created event.
 658         $event = \core\event\course_module_created::create_from_cm($mod);
 659         $event->trigger();
 660
 661         $this->send_response($mod);
 662     }
 663
 664     /**
 665      * Send the details of the newly created activity back to the client browser
 666      *
 667      * @param cm_info $mod details of the mod just created
 668      */
 669     protected function send_response($mod) {
 670         global $OUTPUT, $PAGE;
 671
 672         $resp = new stdClass();
 673         $resp->error = self::ERROR_OK;
 674         $resp->elementid = 'module-' . $mod->id;
 675
 676         $courserenderer = $PAGE->get_renderer('core', 'course');
 677         $completioninfo = new completion_info($this->course);
 678         $info = get_fast_modinfo($this->course);
 679         $sr = null;
 680         $modulehtml = $courserenderer->course_section_cm($this->course, $completioninfo,
 681                 $mod, null, array());
 682         $resp->fullcontent = $courserenderer->course_section_cm_list_item($this->course, $completioninfo, $mod, $sr);
 683
 684         echo $OUTPUT->header();
 685         echo json_encode($resp);
 686         die();
 687     }
 688 }