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Differences Between: [Versions 310 and 403] [Versions 311 and 403] [Versions 39 and 403] [Versions 400 and 403] [Versions 401 and 403]

   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 the LEAP2a writer used by portfolio_format_leap2a
  19   *
  20   * @package core_portfolio
  21   * @copyright 2009 Penny Leach (penny@liip.ch), Martin Dougiamas
  22   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   *
  24   */
  25  
  26  defined('MOODLE_INTERNAL') || die();
  27  
  28  /**
  29   * Object to encapsulate the writing of leap2a.
  30   *
  31   * Should be used like:
  32   * $writer = portfolio_format_leap2a::leap2a_writer($USER);
  33   * $entry = new portfolio_format_leap2a_entry('forumpost6', $title, 'leap2', 'somecontent')
  34   * $entry->add_link('something', 'has_part')->add_link('somethingelse', 'has_part');
  35   * .. etc
  36   * $writer->add_entry($entry);
  37   * $xmlstr = $writer->to_xml();
  38   *
  39   * @todo MDL-31287 - find a way to ensure that all referenced files are included
  40   * @package core_portfolio
  41   * @category portfolio
  42   * @copyright 2009 Penny Leach
  43   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  44   */
  45  class portfolio_format_leap2a_writer {
  46  
  47      /** @var DomDocument the domdocument object used to create elements */
  48      private $dom;
  49  
  50      /** @var DOMElement the top level feed element */
  51      private $feed;
  52  
  53      /** @var stdClass the user exporting data */
  54      private $user;
  55  
  56      /** @var array the entries for the feed - keyed on id */
  57      private $entries = array();
  58  
  59      /**
  60       * Constructor - usually generated from portfolio_format_leap2a::leap2a_writer($USER);
  61       *
  62       * @todo MDL-31302 - add exporter and format
  63       * @param stdclass $user the user exporting (almost always $USER)
  64       */
  65      public function __construct(stdclass $user) { // todo something else - exporter, format, etc
  66          global $CFG;
  67          $this->user = $user;
  68          $id = $CFG->wwwroot . '/portfolio/export/leap2a/' . $this->user->id . '/' . time();
  69  
  70          $this->dom = new DomDocument('1.0', 'utf-8');
  71  
  72          $this->feed = $this->dom->createElement('feed');
  73          $this->feed->setAttribute('xmlns', 'http://www.w3.org/2005/Atom');
  74          $this->feed->setAttribute('xmlns:rdf', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#');
  75          $this->feed->setAttribute('xmlns:leap2', 'http://terms.leapspecs.org/');
  76          $this->feed->setAttribute('xmlns:categories', 'http://wiki.leapspecs.org/2A/categories');
  77          $this->feed->setAttribute('xmlns:portfolio', $id); // This is just a ns for ids of elements for convenience.
  78  
  79          $this->dom->appendChild($this->feed);
  80  
  81          $this->feed->appendChild($this->dom->createElement('id', $id));
  82          $this->feed->appendChild($this->dom->createElement('title', get_string('leap2a_feedtitle', 'portfolio', fullname($this->user))));
  83          $this->feed->appendChild($this->dom->createElement('leap2:version', 'http://www.leapspecs.org/2010-07/2A/'));
  84  
  85  
  86          $generator = $this->dom->createElement('generator', 'Moodle');
  87          $generator->setAttribute('uri', $CFG->wwwroot);
  88          $generator->setAttribute('version', $CFG->version);
  89  
  90          $this->feed->appendChild($generator);
  91  
  92          $author = $this->dom->createElement('author');
  93          $author->appendChild($this->dom->createElement('name', fullname($this->user)));
  94          $author->appendChild($this->dom->createElement('email', $this->user->email));
  95          $author->appendChild($this->dom->CreateElement('uri', $CFG->wwwroot . '/user/view.php?id=' . $this->user->id));
  96  
  97          $this->feed->appendChild($author);
  98          // header done, we can start appending entry elements now
  99      }
 100  
 101      /**
 102       * Adds a entry to the feed ready to be exported
 103       *
 104       * @param portfolio_format_leap2a_entry $entry new feed entry to add
 105       * @return portfolio_format_leap2a_entry
 106       */
 107      public function add_entry(portfolio_format_leap2a_entry $entry) {
 108          if (array_key_exists($entry->id, $this->entries)) {
 109              if (!($entry instanceof portfolio_format_leap2a_file)) {
 110                  throw new portfolio_format_leap2a_exception('leap2a_entryalreadyexists', 'portfolio', '', $entry->id);
 111              }
 112          }
 113          $this->entries[$entry->id] =  $entry;
 114          return $entry;
 115      }
 116  
 117      /**
 118       * Select an entry that has previously been added into the feed
 119       *
 120       * @param portfolio_format_leap2a_entry|string $selectionentry the entry to make a selection (id or entry object)
 121       * @param array $ids array of ids this selection includes
 122       * @param string $selectiontype for selection type, see: http://wiki.cetis.ac.uk/2009-03/LEAP2A_categories/selection_type
 123       */
 124      public function make_selection($selectionentry, $ids, $selectiontype) {
 125          $selectionid = null;
 126          if ($selectionentry instanceof portfolio_format_leap2a_entry) {
 127              $selectionid = $selectionentry->id;
 128          } else if (is_string($selectionentry)) {
 129              $selectionid = $selectionentry;
 130          }
 131          if (!array_key_exists($selectionid, $this->entries)) {
 132              throw new portfolio_format_leap2a_exception('leap2a_invalidentryid', 'portfolio', '', $selectionid);
 133          }
 134          foreach ($ids as $entryid) {
 135              if (!array_key_exists($entryid, $this->entries)) {
 136                  throw new portfolio_format_leap2a_exception('leap2a_invalidentryid', 'portfolio', '', $entryid);
 137              }
 138              $this->entries[$selectionid]->add_link($entryid, 'has_part');
 139              $this->entries[$entryid]->add_link($selectionid, 'is_part_of');
 140          }
 141          $this->entries[$selectionid]->add_category($selectiontype, 'selection_type');
 142          if ($this->entries[$selectionid]->type != 'selection') {
 143              debugging(get_string('leap2a_overwritingselection', 'portfolio', $this->entries[$selectionid]->type));
 144              $this->entries[$selectionid]->type = 'selection';
 145          }
 146      }
 147  
 148      /**
 149       * Helper function to link some stored_files into the feed and link them to a particular entry
 150       *
 151       * @param portfolio_format_leap2a_entry $entry feed object
 152       * @param array $files array of stored_files to link
 153       */
 154      public function link_files($entry, $files) {
 155          foreach ($files as $file) {
 156              $fileentry = new portfolio_format_leap2a_file($file->get_filename(), $file);
 157              $this->add_entry($fileentry);
 158              $entry->add_link($fileentry, 'related');
 159              $fileentry->add_link($entry, 'related');
 160          }
 161      }
 162  
 163      /**
 164       * Validate the feed and all entries
 165       */
 166      private function validate() {
 167          foreach ($this->entries as $entry) {
 168              // first call the entry's own validation method
 169              // which will throw an exception if there's anything wrong
 170              $entry->validate();
 171              // now make sure that all links are in place
 172              foreach ($entry->links as $linkedid => $rel) {
 173                  // the linked to entry exists
 174                  if (!array_key_exists($linkedid, $this->entries)) {
 175                      $a = (object)array('rel' => $rel->type, 'to' => $linkedid, 'from' => $entry->id);
 176                      throw new portfolio_format_leap2a_exception('leap2a_nonexistantlink', 'portfolio', '', $a);
 177                  }
 178                  // and contains a link back to us
 179                  if (!array_key_exists($entry->id, $this->entries[$linkedid]->links)) {
 180  
 181                  }
 182                  // we could later check that the reltypes were properly inverse, but nevermind for now.
 183              }
 184          }
 185      }
 186  
 187      /**
 188       * Return the entire feed as a string.
 189       * Then, it calls for validation
 190       *
 191       * @return string feeds' content in xml
 192       */
 193      public function to_xml() {
 194          $this->validate();
 195          foreach ($this->entries as $entry) {
 196              $entry->id = 'portfolio:' . $entry->id;
 197              $this->feed->appendChild($entry->to_dom($this->dom, $this->user));
 198          }
 199          return $this->dom->saveXML();
 200      }
 201  }
 202  
 203  /**
 204   * This class represents a single leap2a entry.
 205   *
 206   * You can create these directly and then add them to the main leap feed object
 207   *
 208   * @package core_portfolio
 209   * @category portfolio
 210   * @copyright 2009 Penny Leach
 211   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 212   */
 213  class portfolio_format_leap2a_entry {
 214  
 215      /** @var string entry id  - something like forumpost6, must be unique to the feed */
 216      public $id;
 217  
 218      /** @var string title of the entry */
 219      public $title;
 220  
 221      /** @var string leap2a entry type */
 222      public $type;
 223  
 224      /** @var string optional author (only if different to feed author) */
 225      public $author;
 226  
 227      /** @var string summary - for split long content */
 228      public $summary;
 229  
 230      /** @var mixed main content of the entry. can be html,text,or xhtml. for a stored_file, use portfolio_format_leap2a_file **/
 231      public $content;
 232  
 233      /** @var int updated date - unix timestamp */
 234      public $updated;
 235  
 236      /** @var int published date (ctime) - unix timestamp */
 237      public $published;
 238  
 239      /** @var array the required fields for a leap2a entry */
 240      private $requiredfields = array( 'id', 'title', 'type');
 241  
 242      /** @var array extra fields which usually should be set (except author) but are not required */
 243      private $optionalfields = array('author', 'updated', 'published', 'content', 'summary');
 244  
 245      /** @var array links from this entry to other entries */
 246      public $links       = array();
 247  
 248      /** @var array attachments to this entry */
 249      public $attachments = array();
 250  
 251      /** @var array categories for this entry */
 252      private $categories = array();
 253  
 254      /**
 255       * Constructor.  All arguments are required (and will be validated)
 256       * http://wiki.cetis.ac.uk/2009-03/LEAP2A_types
 257       *
 258       * @param string $id unique id of this entry.
 259       *                   could be something like forumpost6 for example.
 260       *                   This <b>must</b> be unique to the entire feed.
 261       * @param string $title title of the entry. This is pure atom.
 262       * @param string $type the leap type of this entry.
 263       * @param mixed $content the content of the entry. string (xhtml/html/text)
 264       */
 265      public function __construct($id, $title, $type, $content=null) {
 266          $this->id    = $id;
 267          $this->title = $title;
 268          $this->type  = $type;
 269          $this->content = $this->__set('content', $content);
 270  
 271      }
 272  
 273      /**
 274       * Override __set to do proper dispatching for different things.
 275       * Only allows the optional and required leap2a entry fields to be set
 276       *
 277       * @param string $field property's name
 278       * @param mixed $value property's value
 279       * @return mixed
 280       */
 281      public function __set($field, $value) {
 282          // detect the case where content is being set to be a file directly
 283          if ($field == 'content' && $value instanceof stored_file) {
 284              throw new portfolio_format_leap2a_exception('leap2a_filecontent', 'portfolio');
 285          }
 286          if (in_array($field, $this->requiredfields) || in_array($field, $this->optionalfields)) {
 287              return $this->{$field} = $value;
 288          }
 289          throw new portfolio_format_leap2a_exception('leap2a_invalidentryfield', 'portfolio', '', $field);
 290      }
 291  
 292  
 293      /**
 294       * Validate this entry.
 295       * At the moment this just makes sure required fields exist
 296       * but it could also check things against a list, for example
 297       *
 298       * @todo MDL-31303 - add category with a scheme 'selection_type'
 299       */
 300      public function validate() {
 301          foreach ($this->requiredfields as $key) {
 302              if (empty($this->{$key})) {
 303                  throw new portfolio_format_leap2a_exception('leap2a_missingfield', 'portfolio', '', $key);
 304              }
 305          }
 306          if ($this->type == 'selection') {
 307              if (count($this->links) == 0) {
 308                  throw new portfolio_format_leap2a_exception('leap2a_emptyselection', 'portfolio');
 309              }
 310              //TODO make sure we have a category with a scheme 'selection_type'
 311          }
 312      }
 313  
 314      /**
 315       * Add a link from this entry to another one.
 316       * These will be collated at the end of the export (during to_xml)
 317       * and validated at that point. This function does no validation
 318       * {@link http://wiki.cetis.ac.uk/2009-03/LEAP2A_relationships}
 319       *
 320       * @param portfolio_format_leap2a_entry|string $otherentry portfolio_format_leap2a_entry or its id
 321       * @param string $reltype (no leap2: ns required)
 322       * @param string $displayorder (optional)
 323       * @return portfolio_format_leap2a_entry the current entry object. This is so that these calls can be chained
 324       *                                       eg $entry->add_link('something6', 'has_part')->add_link('something7',
 325       *                                       'has_part');
 326       */
 327      public function add_link($otherentry, $reltype, $displayorder=null) {
 328          if ($otherentry instanceof portfolio_format_leap2a_entry) {
 329              $otherentry = $otherentry->id;
 330          }
 331          if ($otherentry == $this->id) {
 332              throw new portfolio_format_leap2a_exception('leap2a_selflink', 'portfolio', '', (object)array('rel' => $reltype, 'id' => $this->id));
 333          }
 334          // add on the leap2: ns if required
 335          if (!in_array($reltype, array('related', 'alternate', 'enclosure'))) {
 336              $reltype = 'leap2:' . $reltype;
 337          }
 338  
 339          $this->links[$otherentry] = (object)array('rel' => $reltype, 'order' => $displayorder);
 340  
 341          return $this;
 342      }
 343  
 344      /**
 345       * Add a category to this entry
 346       * {@link http://wiki.cetis.ac.uk/2009-03/LEAP2A_categories}
 347       * "tags" should just pass a term here and no scheme or label.
 348       * They will be automatically normalised if they have spaces.
 349       *
 350       * @param string $term eg 'Offline'
 351       * @param string $scheme (optional) eg resource_type
 352       * @param string $label (optional) eg File
 353       */
 354      public function add_category($term, $scheme=null, $label=null) {
 355          // "normalise" terms and set their label if they have spaces
 356          // see http://wiki.cetis.ac.uk/2009-03/LEAP2A_categories#Plain_tags for more information
 357          if (empty($scheme) && strpos($term, ' ') !== false) {
 358              $label = $term;
 359              $term = str_replace(' ', '-', $term);
 360          }
 361          $this->categories[] = (object)array(
 362              'term'   => $term,
 363              'scheme' => $scheme,
 364              'label'  => $label,
 365          );
 366      }
 367  
 368      /**
 369       * Create an entry element and append all the children
 370       * And return it rather than adding it to the dom.
 371       * This is handled by the main writer object.
 372       *
 373       * @param DomDocument $dom use this to create elements
 374       * @param stdClass $feedauthor object of author(user) info
 375       * @return DOMDocument
 376       */
 377      public function to_dom(DomDocument $dom, $feedauthor) {
 378          $entry = $dom->createElement('entry');
 379          $entry->appendChild($dom->createElement('id', $this->id));
 380          $entry->appendChild($dom->createElement('title', $this->title));
 381          if ($this->author && $this->author->id != $feedauthor->id) {
 382              $author = $dom->createElement('author');
 383              $author->appendChild($dom->createElement('name', fullname($this->author)));
 384              $entry->appendChild($author);
 385          }
 386          // selectively add uncomplicated optional elements
 387          foreach (array('updated', 'published') as $field) {
 388              if ($this->{$field}) {
 389                  $date = date(DATE_ATOM, $this->{$field});
 390                  $entry->appendChild($dom->createElement($field, $date));
 391              }
 392          }
 393          if (empty($this->content)) {
 394              $entry->appendChild($dom->createElement('content'));
 395          } else {
 396              $content = $this->create_xhtmlish_element($dom, 'content', $this->content);
 397              $entry->appendChild($content);
 398          }
 399  
 400          if (!empty($this->summary)) {
 401              $summary = $this->create_xhtmlish_element($dom, 'summary', $this->summary);
 402              $entry->appendChild($summary);
 403          }
 404  
 405          $type = $dom->createElement('rdf:type');
 406          $type->setAttribute('rdf:resource', 'leap2:' . $this->type);
 407          $entry->appendChild($type);
 408  
 409          foreach ($this->links as $otherentry => $l) {
 410              $link = $dom->createElement('link');
 411              $link->setAttribute('rel',  $l->rel);
 412              $link->setAttribute('href', 'portfolio:' . $otherentry);
 413              if ($l->order) {
 414                  $link->setAttribute('leap2:display_order', $l->order);
 415              }
 416              $entry->appendChild($link);
 417          }
 418  
 419          $this->add_extra_links($dom, $entry); // hook for subclass
 420  
 421          foreach ($this->categories as $category) {
 422              $cat = $dom->createElement('category');
 423              $cat->setAttribute('term', $category->term);
 424              if ($category->scheme) {
 425                  $cat->setAttribute('scheme', 'categories:' .$category->scheme . '#');
 426              }
 427              if ($category->label && $category->label != $category->term) {
 428                  $cat->setAttribute('label', $category->label);
 429              }
 430              $entry->appendChild($cat);
 431          }
 432          return $entry;
 433      }
 434  
 435      /**
 436       * Try to load whatever is in $content into xhtml and add it to the dom.
 437       * Failing that, load the html, escape it, and set it as the body of the tag.
 438       * Either way it sets the type attribute of the top level element.
 439       * Moodle should always provide xhtml content, but user-defined content can't be trusted
 440       *
 441       * @todo MDL-31304 - convert <html><body> </body></html> to xml
 442       * @param DomDocument $dom the dom doc to use
 443       * @param string $tagname usually 'content' or 'summary'
 444       * @param string $content the content to use, either xhtml or html.
 445       * @return DomDocument
 446       */
 447      private function create_xhtmlish_element(DomDocument $dom, $tagname, $content) {
 448          $topel = $dom->createElement($tagname);
 449          $maybexml = true;
 450          if (strpos($content, '<') === false && strpos($content, '>') === false) {
 451              $maybexml = false;
 452          }
 453          // try to load content as xml
 454          $tmp = new DomDocument();
 455          if ($maybexml && @$tmp->loadXML('<div>' . $content . '</div>')) {
 456              $topel->setAttribute('type', 'xhtml');
 457              $content = $dom->importNode($tmp->documentElement, true);
 458              $content->setAttribute('xmlns', 'http://www.w3.org/1999/xhtml');
 459              $topel->appendChild($content);
 460          // if that fails, it could still be html
 461          } else if ($maybexml && @$tmp->loadHTML($content)) {
 462              $topel->setAttribute('type', 'html');
 463              $topel->nodeValue = $content;
 464              // TODO figure out how to convert this to xml
 465              // TODO because we end up with <html><body> </body></html> wrapped around it
 466              // which is annoying
 467          // either we already know it's text from the first check
 468          // or nothing else has worked anyway
 469          } else {
 470              $topel->nodeValue = $content;
 471              $topel->setAttribute('type', 'text');
 472              return $topel;
 473          }
 474          return $topel;
 475      }
 476  
 477      /**
 478       * Hook function for subclasses to add extra links (like for files)
 479       *
 480       * @param DomDocument $dom feed object
 481       * @param DomDocument $entry feed added link
 482       */
 483      protected function add_extra_links($dom, $entry) {}
 484  }
 485  
 486  /**
 487   * Subclass of entry, purely for dealing with files
 488   *
 489   * @package core_portfolio
 490   * @category portfolio
 491   * @copyright 2009 Penny Leach
 492   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 493   */
 494  class portfolio_format_leap2a_file extends portfolio_format_leap2a_entry {
 495  
 496      /** @var file_stored for the dealing file */
 497      protected $referencedfile;
 498  
 499      /**
 500       * Overridden constructor to set up the file.
 501       *
 502       * @param string $title title of the entry
 503       * @param stored_file $file file storage instance
 504       */
 505      public function __construct($title, stored_file $file) {
 506          $id = portfolio_format_leap2a::file_id_prefix() . $file->get_id();
 507          parent::__construct($id, $title, 'resource');
 508          $this->referencedfile = $file;
 509          $this->published = $this->referencedfile->get_timecreated();
 510          $this->updated = $this->referencedfile->get_timemodified();
 511          $this->add_category('offline', 'resource_type');
 512      }
 513  
 514      /**
 515       * Implement the hook to add extra links to attach the file in an enclosure
 516       *
 517       * @param DomDocument $dom feed object
 518       * @param DomDocument $entry feed added link
 519       */
 520      protected function add_extra_links($dom, $entry) {
 521          $link = $dom->createElement('link');
 522          $link->setAttribute('rel',  'enclosure');
 523          $link->setAttribute('href', portfolio_format_leap2a::get_file_directory() . $this->referencedfile->get_filename());
 524          $link->setAttribute('length', $this->referencedfile->get_filesize());
 525          $link->setAttribute('type', $this->referencedfile->get_mimetype());
 526          $entry->appendChild($link);
 527      }
 528  }
 529