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   1  <?php
   2  // This file is part of Moodle - http://moodle.org/
   3  //
   4  // Moodle is free software: you can redistribute it and/or modify
   5  // it under the terms of the GNU General Public License as published by
   6  // the Free Software Foundation, either version 3 of the License, or
   7  // (at your option) any later version.
   8  //
   9  // Moodle is distributed in the hope that it will be useful,
  10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  // GNU General Public License for more details.
  13  //
  14  // You should have received a copy of the GNU General Public License
  15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16  
  17  /**
  18   * Classes for Blogs.
  19   *
  20   * @package    moodlecore
  21   * @subpackage blog
  22   * @copyright  2009 Nicolas Connault
  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->libdir . '/filelib.php');
  29  
  30  /**
  31   * Blog_entry class. Represents an entry in a user's blog. Contains all methods for managing this entry.
  32   * This class does not contain any HTML-generating code. See blog_listing sub-classes for such code.
  33   * This class follows the Object Relational Mapping technique, its member variables being mapped to
  34   * the fields of the post table.
  35   *
  36   * @package    moodlecore
  37   * @subpackage blog
  38   * @copyright  2009 Nicolas Connault
  39   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  40   */
  41  class blog_entry implements renderable {
  42      // Public Database fields.
  43      public $id;
  44      public $userid;
  45      public $subject;
  46      public $summary;
  47      public $rating = 0;
  48      public $attachment;
  49      public $publishstate;
  50  
  51      // Locked Database fields (Don't touch these).
  52      public $courseid = 0;
  53      public $groupid = 0;
  54      public $module = 'blog';
  55      public $moduleid = 0;
  56      public $coursemoduleid = 0;
  57      public $content;
  58      public $format = 1;
  59      public $uniquehash = '';
  60      public $lastmodified;
  61      public $created;
  62      public $usermodified;
  63  
  64      // Other class variables.
  65      public $form;
  66      public $tags = array();
  67  
  68      /** @var StdClass Data needed to render the entry */
  69      public $renderable;
  70  
  71      /**
  72       * Constructor. If given an id, will fetch the corresponding record from the DB.
  73       *
  74       * @param mixed $idorparams A blog entry id if INT, or data for a new entry if array
  75       */
  76      public function __construct($id=null, $params=null, $form=null) {
  77          global $DB, $PAGE, $CFG;
  78  
  79          if (!empty($id)) {
  80              $object = $DB->get_record('post', array('id' => $id));
  81              foreach ($object as $var => $val) {
  82                  $this->$var = $val;
  83              }
  84          } else if (!empty($params) && (is_array($params) || is_object($params))) {
  85              foreach ($params as $var => $val) {
  86                  $this->$var = $val;
  87              }
  88          }
  89  
  90          if (!empty($CFG->useblogassociations)) {
  91              $associations = $DB->get_records('blog_association', array('blogid' => $this->id));
  92              foreach ($associations as $association) {
  93                  $context = context::instance_by_id($association->contextid);
  94                  if ($context->contextlevel == CONTEXT_COURSE) {
  95                      $this->courseassoc = $association->contextid;
  96                  } else if ($context->contextlevel == CONTEXT_MODULE) {
  97                      $this->modassoc = $association->contextid;
  98                  }
  99              }
 100          }
 101  
 102          $this->form = $form;
 103      }
 104  
 105  
 106      /**
 107       * Gets the required data to print the entry
 108       */
 109      public function prepare_render() {
 110  
 111          global $DB, $CFG, $PAGE;
 112  
 113          $this->renderable = new StdClass();
 114  
 115          $this->renderable->user = $DB->get_record('user', array('id'=>$this->userid));
 116  
 117          // Entry comments.
 118          if (!empty($CFG->usecomments) and $CFG->blogusecomments) {
 119              require_once($CFG->dirroot . '/comment/lib.php');
 120  
 121              $cmt = new stdClass();
 122              $cmt->context = context_user::instance($this->userid);
 123              $cmt->courseid = $PAGE->course->id;
 124              $cmt->area = 'format_blog';
 125              $cmt->itemid = $this->id;
 126              $cmt->showcount = $CFG->blogshowcommentscount;
 127              $cmt->component = 'blog';
 128              $this->renderable->comment = new comment($cmt);
 129          }
 130  
 131          $this->summary = file_rewrite_pluginfile_urls($this->summary, 'pluginfile.php', SYSCONTEXTID, 'blog', 'post', $this->id);
 132  
 133          // External blog link.
 134          if ($this->uniquehash && $this->content) {
 135              if ($externalblog = $DB->get_record('blog_external', array('id' => $this->content))) {
 136                  $urlparts = parse_url($externalblog->url);
 137                  $this->renderable->externalblogtext = get_string('retrievedfrom', 'blog') . get_string('labelsep', 'langconfig');
 138                  $this->renderable->externalblogtext .= html_writer::link($urlparts['scheme'] . '://' . $urlparts['host'],
 139                                                                           $externalblog->name);
 140              }
 141          }
 142  
 143          // Retrieve associations.
 144          $this->renderable->unassociatedentry = false;
 145          if (!empty($CFG->useblogassociations)) {
 146  
 147              // Adding the entry associations data.
 148              if ($associations = $associations = $DB->get_records('blog_association', array('blogid' => $this->id))) {
 149  
 150                  // Check to see if the entry is unassociated with group/course level access.
 151                  if ($this->publishstate == 'group' || $this->publishstate == 'course') {
 152                      $this->renderable->unassociatedentry = true;
 153                  }
 154  
 155                  foreach ($associations as $key => $assocrec) {
 156  
 157                      if (!$context = context::instance_by_id($assocrec->contextid, IGNORE_MISSING)) {
 158                          unset($associations[$key]);
 159                          continue;
 160                      }
 161  
 162                      // The renderer will need the contextlevel of the association.
 163                      $associations[$key]->contextlevel = $context->contextlevel;
 164  
 165                      // Course associations.
 166                      if ($context->contextlevel ==  CONTEXT_COURSE) {
 167                          // TODO: performance!!!!
 168                          $instancename = $DB->get_field('course', 'shortname', array('id' => $context->instanceid));
 169  
 170                          $associations[$key]->url = $assocurl = new moodle_url('/course/view.php',
 171                                                                                array('id' => $context->instanceid));
 172                          $associations[$key]->text = $instancename;
 173                          $associations[$key]->icon = new pix_icon('i/course', $associations[$key]->text);
 174                      }
 175  
 176                      // Mod associations.
 177                      if ($context->contextlevel ==  CONTEXT_MODULE) {
 178  
 179                          // Getting the activity type and the activity instance id.
 180                          $sql = 'SELECT cm.instance, m.name FROM {course_modules} cm
 181                                    JOIN {modules} m ON m.id = cm.module
 182                                   WHERE cm.id = :cmid';
 183                          $modinfo = $DB->get_record_sql($sql, array('cmid' => $context->instanceid));
 184                          // TODO: performance!!!!
 185                          $instancename = $DB->get_field($modinfo->name, 'name', array('id' => $modinfo->instance));
 186  
 187                          $associations[$key]->type = get_string('modulename', $modinfo->name);
 188                          $associations[$key]->url = new moodle_url('/mod/' . $modinfo->name . '/view.php',
 189                                                                    array('id' => $context->instanceid));
 190                          $associations[$key]->text = $instancename;
 191                          $associations[$key]->icon = new pix_icon('icon', $associations[$key]->text, $modinfo->name);
 192                      }
 193                  }
 194              }
 195              $this->renderable->blogassociations = $associations;
 196          }
 197  
 198          // Entry attachments.
 199          $this->renderable->attachments = $this->get_attachments();
 200  
 201          $this->renderable->usercanedit = blog_user_can_edit_entry($this);
 202      }
 203  
 204  
 205      /**
 206       * Gets the entry attachments list
 207       * @return array List of blog_entry_attachment instances
 208       */
 209      public function get_attachments() {
 210  
 211          global $CFG;
 212  
 213          require_once($CFG->libdir.'/filelib.php');
 214  
 215          $syscontext = context_system::instance();
 216  
 217          $fs = get_file_storage();
 218          $files = $fs->get_area_files($syscontext->id, 'blog', 'attachment', $this->id);
 219  
 220          // Adding a blog_entry_attachment for each non-directory file.
 221          $attachments = array();
 222          foreach ($files as $file) {
 223              if ($file->is_directory()) {
 224                  continue;
 225              }
 226              $attachments[] = new blog_entry_attachment($file, $this->id);
 227          }
 228  
 229          return $attachments;
 230      }
 231  
 232      /**
 233       * Inserts this entry in the database. Access control checks must be done by calling code.
 234       *
 235       * @param mform $form Used for attachments
 236       * @return void
 237       */
 238      public function process_attachment($form) {
 239          $this->form = $form;
 240      }
 241  
 242      /**
 243       * Inserts this entry in the database. Access control checks must be done by calling code.
 244       * TODO Set the publishstate correctly
 245       * @return void
 246       */
 247      public function add() {
 248          global $CFG, $USER, $DB;
 249  
 250          unset($this->id);
 251          $this->module       = 'blog';
 252          $this->userid       = (empty($this->userid)) ? $USER->id : $this->userid;
 253          $this->lastmodified = time();
 254          $this->created      = time();
 255  
 256          // Insert the new blog entry.
 257          $this->id = $DB->insert_record('post', $this);
 258  
 259          // Update tags.
 260          $this->add_tags_info();
 261  
 262          if (!empty($CFG->useblogassociations)) {
 263              $this->add_associations();
 264          }
 265  
 266          tag_set('post', $this->id, $this->tags, 'core', context_user::instance($this->userid)->id);
 267  
 268          // Trigger an event for the new entry.
 269          $event = \core\event\blog_entry_created::create(array(
 270              'objectid'      => $this->id,
 271              'relateduserid' => $this->userid
 272          ));
 273          $event->set_blog_entry($this);
 274          $event->trigger();
 275      }
 276  
 277      /**
 278       * Updates this entry in the database. Access control checks must be done by calling code.
 279       *
 280       * @param array       $params            Entry parameters.
 281       * @param moodleform  $form              Used for attachments.
 282       * @param array       $summaryoptions    Summary options.
 283       * @param array       $attachmentoptions Attachment options.
 284       *
 285       * @return void
 286       */
 287      public function edit($params=array(), $form=null, $summaryoptions=array(), $attachmentoptions=array()) {
 288          global $CFG, $DB;
 289  
 290          $sitecontext = context_system::instance();
 291          $entry = $this;
 292  
 293          $this->form = $form;
 294          foreach ($params as $var => $val) {
 295              $entry->$var = $val;
 296          }
 297  
 298          $entry = file_postupdate_standard_editor($entry, 'summary', $summaryoptions, $sitecontext, 'blog', 'post', $entry->id);
 299          $entry = file_postupdate_standard_filemanager($entry,
 300                                                        'attachment',
 301                                                        $attachmentoptions,
 302                                                        $sitecontext,
 303                                                        'blog',
 304                                                        'attachment',
 305                                                        $entry->id);
 306  
 307          if (!empty($CFG->useblogassociations)) {
 308              $entry->add_associations();
 309          }
 310  
 311          $entry->lastmodified = time();
 312  
 313          // Update record.
 314          $DB->update_record('post', $entry);
 315          tag_set('post', $entry->id, $entry->tags, 'core', context_user::instance($this->userid)->id);
 316  
 317          $event = \core\event\blog_entry_updated::create(array(
 318              'objectid'      => $entry->id,
 319              'relateduserid' => $entry->userid
 320          ));
 321          $event->set_blog_entry($entry);
 322          $event->trigger();
 323      }
 324  
 325      /**
 326       * Deletes this entry from the database. Access control checks must be done by calling code.
 327       *
 328       * @return void
 329       */
 330      public function delete() {
 331          global $DB;
 332  
 333          $this->delete_attachments();
 334          $this->remove_associations();
 335  
 336          // Get record to pass onto the event.
 337          $record = $DB->get_record('post', array('id' => $this->id));
 338          $DB->delete_records('post', array('id' => $this->id));
 339          tag_set('post', $this->id, array(), 'core', context_user::instance($this->userid)->id);
 340  
 341          $event = \core\event\blog_entry_deleted::create(array(
 342              'objectid'      => $this->id,
 343              'relateduserid' => $this->userid
 344              ));
 345          $event->add_record_snapshot("post", $record);
 346          $event->set_blog_entry($this);
 347          $event->trigger();
 348      }
 349  
 350      /**
 351       * Function to add all context associations to an entry.
 352       * TODO : Remove $action in 2.9 (MDL-41330)
 353       *
 354       * @param string $action - This does nothing, do not use it. This is present only for Backward compatibility.
 355       */
 356      public function add_associations($action = null) {
 357  
 358          if (!empty($action)) {
 359              debugging('blog_entry->add_associations() does not accept any argument', DEBUG_DEVELOPER);
 360          }
 361  
 362          $this->remove_associations();
 363  
 364          if (!empty($this->courseassoc)) {
 365              $this->add_association($this->courseassoc);
 366          }
 367  
 368          if (!empty($this->modassoc)) {
 369              $this->add_association($this->modassoc);
 370          }
 371      }
 372  
 373      /**
 374       * Add a single association for a blog entry
 375       * TODO : Remove $action in 2.9 (MDL-41330)
 376       *
 377       * @param int $contextid - id of context to associate with the blog entry.
 378       * @param string $action - This does nothing, do not use it. This is present only for Backward compatibility.
 379       */
 380      public function add_association($contextid, $action = null) {
 381          global $DB;
 382  
 383          if (!empty($action)) {
 384              debugging('blog_entry->add_association() accepts only one argument', DEBUG_DEVELOPER);
 385          }
 386  
 387          $assocobject = new StdClass;
 388          $assocobject->contextid = $contextid;
 389          $assocobject->blogid = $this->id;
 390          $id = $DB->insert_record('blog_association', $assocobject);
 391  
 392          // Trigger an association created event.
 393          $context = context::instance_by_id($contextid);
 394          $eventparam = array(
 395              'objectid' => $id,
 396              'other' => array('associateid' => $context->instanceid, 'subject' => $this->subject, 'blogid' => $this->id),
 397              'relateduserid' => $this->userid
 398          );
 399          if ($context->contextlevel == CONTEXT_COURSE) {
 400              $eventparam['other']['associatetype'] = 'course';
 401  
 402          } else if ($context->contextlevel == CONTEXT_MODULE) {
 403              $eventparam['other']['associatetype'] = 'coursemodule';
 404          }
 405          $event = \core\event\blog_association_created::create($eventparam);
 406          $event->trigger();
 407      }
 408  
 409      /**
 410       * remove all associations for a blog entry
 411       * @return voic
 412       */
 413      public function remove_associations() {
 414          global $DB;
 415          $DB->delete_records('blog_association', array('blogid' => $this->id));
 416      }
 417  
 418      /**
 419       * Deletes all the user files in the attachments area for an entry
 420       *
 421       * @return void
 422       */
 423      public function delete_attachments() {
 424          $fs = get_file_storage();
 425          $fs->delete_area_files(SYSCONTEXTID, 'blog', 'attachment', $this->id);
 426          $fs->delete_area_files(SYSCONTEXTID, 'blog', 'post', $this->id);
 427      }
 428  
 429      /**
 430       * function to attach tags into an entry
 431       * @return void
 432       */
 433      public function add_tags_info() {
 434  
 435          $tags = array();
 436  
 437          if ($otags = optional_param('otags', '', PARAM_INT)) {
 438              foreach ($otags as $tagid) {
 439                  // TODO : make this use the tag name in the form.
 440                  if ($tag = tag_get('id', $tagid)) {
 441                      $tags[] = $tag->name;
 442                  }
 443              }
 444          }
 445  
 446          tag_set('post', $this->id, $tags, 'core', context_user::instance($this->userid)->id);
 447      }
 448  
 449      /**
 450       * User can edit a blog entry if this is their own blog entry and they have
 451       * the capability moodle/blog:create, or if they have the capability
 452       * moodle/blog:manageentries.
 453       * This also applies to deleting of entries.
 454       *
 455       * @param int $userid Optional. If not given, $USER is used
 456       * @return boolean
 457       */
 458      public function can_user_edit($userid=null) {
 459          global $CFG, $USER;
 460  
 461          if (empty($userid)) {
 462              $userid = $USER->id;
 463          }
 464  
 465          $sitecontext = context_system::instance();
 466  
 467          if (has_capability('moodle/blog:manageentries', $sitecontext)) {
 468              return true; // Can edit any blog entry.
 469          }
 470  
 471          if ($this->userid == $userid && has_capability('moodle/blog:create', $sitecontext)) {
 472              return true; // Can edit own when having blog:create capability.
 473          }
 474  
 475          return false;
 476      }
 477  
 478      /**
 479       * Checks to see if a user can view the blogs of another user.
 480       * Only blog level is checked here, the capabilities are enforced
 481       * in blog/index.php
 482       *
 483       * @param int $targetuserid ID of the user we are checking
 484       *
 485       * @return bool
 486       */
 487      public function can_user_view($targetuserid) {
 488          global $CFG, $USER, $DB;
 489          $sitecontext = context_system::instance();
 490  
 491          if (empty($CFG->enableblogs) || !has_capability('moodle/blog:view', $sitecontext)) {
 492              return false; // Blog system disabled or user has no blog view capability.
 493          }
 494  
 495          if (isloggedin() && $USER->id == $targetuserid) {
 496              return true; // Can view own entries in any case.
 497          }
 498  
 499          if (has_capability('moodle/blog:manageentries', $sitecontext)) {
 500              return true; // Can manage all entries.
 501          }
 502  
 503          // Coming for 1 entry, make sure it's not a draft.
 504          if ($this->publishstate == 'draft' && !has_capability('moodle/blog:viewdrafts', $sitecontext)) {
 505              return false;  // Can not view draft of others.
 506          }
 507  
 508          // Coming for 1 entry, make sure user is logged in, if not a public blog.
 509          if ($this->publishstate != 'public' && !isloggedin()) {
 510              return false;
 511          }
 512  
 513          switch ($CFG->bloglevel) {
 514              case BLOG_GLOBAL_LEVEL:
 515                  return true;
 516                  break;
 517  
 518              case BLOG_SITE_LEVEL:
 519                  if (isloggedin()) { // Not logged in viewers forbidden.
 520                      return true;
 521                  }
 522                  return false;
 523                  break;
 524  
 525              case BLOG_USER_LEVEL:
 526              default:
 527                  $personalcontext = context_user::instance($targetuserid);
 528                  return has_capability('moodle/user:readuserblogs', $personalcontext);
 529                  break;
 530          }
 531      }
 532  
 533      /**
 534       * Use this function to retrieve a list of publish states available for
 535       * the currently logged in user.
 536       *
 537       * @return array This function returns an array ideal for sending to moodles'
 538       *                choose_from_menu function.
 539       */
 540  
 541      public static function get_applicable_publish_states() {
 542          global $CFG;
 543          $options = array();
 544  
 545          // Everyone gets draft access.
 546          if ($CFG->bloglevel >= BLOG_USER_LEVEL) {
 547              $options['draft'] = get_string('publishtonoone', 'blog');
 548          }
 549  
 550          if ($CFG->bloglevel > BLOG_USER_LEVEL) {
 551              $options['site'] = get_string('publishtosite', 'blog');
 552          }
 553  
 554          if ($CFG->bloglevel >= BLOG_GLOBAL_LEVEL) {
 555              $options['public'] = get_string('publishtoworld', 'blog');
 556          }
 557  
 558          return $options;
 559      }
 560  }
 561  
 562  /**
 563   * Abstract Blog_Listing class: used to gather blog entries and output them as listings. One of the subclasses must be used.
 564   *
 565   * @package    moodlecore
 566   * @subpackage blog
 567   * @copyright  2009 Nicolas Connault
 568   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 569   */
 570  class blog_listing {
 571      /**
 572       * Array of blog_entry objects.
 573       * @var array $entries
 574       */
 575      public $entries = array();
 576  
 577      /**
 578       * An array of blog_filter_* objects
 579       * @var array $filters
 580       */
 581      public $filters = array();
 582  
 583      /**
 584       * Constructor
 585       *
 586       * @param array $filters An associative array of filtername => filterid
 587       */
 588      public function __construct($filters=array()) {
 589          // Unset filters overridden by more specific filters.
 590          foreach ($filters as $type => $id) {
 591              if (!empty($type) && !empty($id)) {
 592                  $this->filters[$type] = blog_filter::get_instance($id, $type);
 593              }
 594          }
 595  
 596          foreach ($this->filters as $type => $filter) {
 597              foreach ($filter->overrides as $override) {
 598                  if (array_key_exists($override, $this->filters)) {
 599                      unset($this->filters[$override]);
 600                  }
 601              }
 602          }
 603      }
 604  
 605      /**
 606       * Fetches the array of blog entries.
 607       *
 608       * @return array
 609       */
 610      public function get_entries($start=0, $limit=10) {
 611          global $DB;
 612  
 613          if (empty($this->entries)) {
 614              if ($sqlarray = $this->get_entry_fetch_sql(false, 'created DESC')) {
 615                  $this->entries = $DB->get_records_sql($sqlarray['sql'], $sqlarray['params'], $start, $limit);
 616              } else {
 617                  return false;
 618              }
 619          }
 620  
 621          return $this->entries;
 622      }
 623  
 624      public function get_entry_fetch_sql($count=false, $sort='lastmodified DESC', $userid = false) {
 625          global $DB, $USER, $CFG;
 626  
 627          if (!$userid) {
 628              $userid = $USER->id;
 629          }
 630  
 631          $allnamefields = get_all_user_name_fields(true, 'u');
 632          // The query used to locate blog entries is complicated.  It will be built from the following components:
 633          $requiredfields = "p.*, $allnamefields, u.email";  // The SELECT clause.
 634          $tables = array('p' => 'post', 'u' => 'user');   // Components of the FROM clause (table_id => table_name).
 635          // Components of the WHERE clause (conjunction).
 636          $conditions = array('u.deleted = 0', 'p.userid = u.id', '(p.module = \'blog\' OR p.module = \'blog_external\')');
 637  
 638          // Build up a clause for permission constraints.
 639  
 640          $params = array();
 641  
 642          // Fix for MDL-9165, use with readuserblogs capability in a user context can read that user's private blogs.
 643          // Admins can see all blogs regardless of publish states, as described on the help page.
 644          if (has_capability('moodle/user:readuserblogs', context_system::instance())) {
 645              // Don't add permission constraints.
 646  
 647          } else if (!empty($this->filters['user'])
 648                     && has_capability('moodle/user:readuserblogs',
 649                                       context_user::instance((empty($this->filters['user']->id) ? 0 : $this->filters['user']->id)))) {
 650              // Don't add permission constraints.
 651  
 652          } else {
 653              if (isloggedin() and !isguestuser()) {
 654                  // Dont check association records if there aren't any.
 655                  $assocexists = $DB->record_exists('blog_association', array());
 656  
 657                  // Begin permission sql clause.
 658                  $permissionsql =  '(p.userid = ? ';
 659                  $params[] = $userid;
 660  
 661                  if ($CFG->bloglevel >= BLOG_SITE_LEVEL) { // Add permission to view site-level entries.
 662                      $permissionsql .= " OR p.publishstate = 'site' ";
 663                  }
 664  
 665                  if ($CFG->bloglevel >= BLOG_GLOBAL_LEVEL) { // Add permission to view global entries.
 666                      $permissionsql .= " OR p.publishstate = 'public' ";
 667                  }
 668  
 669                  $permissionsql .= ') ';   // Close permissions sql clause.
 670              } else {  // Default is access to public entries.
 671                  $permissionsql = "p.publishstate = 'public'";
 672              }
 673              $conditions[] = $permissionsql;  // Add permission constraints.
 674          }
 675  
 676          foreach ($this->filters as $type => $blogfilter) {
 677              $conditions = array_merge($conditions, $blogfilter->conditions);
 678              $params = array_merge($params, $blogfilter->params);
 679              $tables = array_merge($tables, $blogfilter->tables);
 680          }
 681  
 682          $tablessql = '';  // Build up the FROM clause.
 683          foreach ($tables as $tablename => $table) {
 684              $tablessql .= ($tablessql ? ', ' : '').'{'.$table.'} '.$tablename;
 685          }
 686  
 687          $sql = ($count) ? 'SELECT COUNT(*)' : 'SELECT ' . $requiredfields;
 688          $sql .= " FROM $tablessql WHERE " . implode(' AND ', $conditions);
 689          $sql .= ($count) ? '' : " ORDER BY $sort";
 690  
 691          return array('sql' => $sql, 'params' => $params);
 692      }
 693  
 694      /**
 695       * Outputs all the blog entries aggregated by this blog listing.
 696       *
 697       * @return void
 698       */
 699      public function print_entries() {
 700          global $CFG, $USER, $DB, $OUTPUT, $PAGE;
 701          $sitecontext = context_system::instance();
 702  
 703          // Blog renderer.
 704          $output = $PAGE->get_renderer('blog');
 705  
 706          $page  = optional_param('blogpage', 0, PARAM_INT);
 707          $limit = optional_param('limit', get_user_preferences('blogpagesize', 10), PARAM_INT);
 708          $start = $page * $limit;
 709  
 710          $morelink = '<br />&nbsp;&nbsp;';
 711  
 712          if ($sqlarray = $this->get_entry_fetch_sql(true)) {
 713              $totalentries = $DB->count_records_sql($sqlarray['sql'], $sqlarray['params']);
 714          } else {
 715              $totalentries = 0;
 716          }
 717  
 718          $entries = $this->get_entries($start, $limit);
 719          $pagingbar = new paging_bar($totalentries, $page, $limit, $this->get_baseurl());
 720          $pagingbar->pagevar = 'blogpage';
 721          $blogheaders = blog_get_headers();
 722  
 723          echo $OUTPUT->render($pagingbar);
 724  
 725          if (has_capability('moodle/blog:create', $sitecontext)) {
 726              // The user's blog is enabled and they are viewing their own blog.
 727              $userid = optional_param('userid', null, PARAM_INT);
 728  
 729              if (empty($userid) || (!empty($userid) && $userid == $USER->id)) {
 730  
 731                  $courseid = optional_param('courseid', null, PARAM_INT);
 732                  $modid = optional_param('modid', null, PARAM_INT);
 733  
 734                  $addurl = new moodle_url("$CFG->wwwroot/blog/edit.php");
 735                  $urlparams = array('action' => 'add',
 736                                     'userid' => $userid,
 737                                     'courseid' => $courseid,
 738                                     'groupid' => optional_param('groupid', null, PARAM_INT),
 739                                     'modid' => $modid,
 740                                     'tagid' => optional_param('tagid', null, PARAM_INT),
 741                                     'tag' => optional_param('tag', null, PARAM_INT),
 742                                     'search' => optional_param('search', null, PARAM_INT));
 743  
 744                  $urlparams = array_filter($urlparams);
 745                  $addurl->params($urlparams);
 746  
 747                  $addlink = '<div class="addbloglink">';
 748                  $addlink .= '<a href="'.$addurl->out().'">'. $blogheaders['stradd'].'</a>';
 749                  $addlink .= '</div>';
 750                  echo $addlink;
 751              }
 752          }
 753  
 754          if ($entries) {
 755              $count = 0;
 756              foreach ($entries as $entry) {
 757                  $blogentry = new blog_entry(null, $entry);
 758  
 759                  // Get the required blog entry data to render it.
 760                  $blogentry->prepare_render();
 761                  echo $output->render($blogentry);
 762  
 763                  $count++;
 764              }
 765  
 766              echo $OUTPUT->render($pagingbar);
 767  
 768              if (!$count) {
 769                  print '<br /><div style="text-align:center">'. get_string('noentriesyet', 'blog') .'</div><br />';
 770              }
 771  
 772              print $morelink.'<br />'."\n";
 773              return;
 774          }
 775      }
 776  
 777      // Find the base url from $_GET variables, for print_paging_bar.
 778      public function get_baseurl() {
 779          $getcopy  = $_GET;
 780  
 781          unset($getcopy['blogpage']);
 782  
 783          if (!empty($getcopy)) {
 784              $first = false;
 785              $querystring = '';
 786  
 787              foreach ($getcopy as $var => $val) {
 788                  if (!$first) {
 789                      $first = true;
 790                      $querystring .= "?$var=$val";
 791                  } else {
 792                      $querystring .= '&amp;'.$var.'='.$val;
 793                      $hasparam = true;
 794                  }
 795              }
 796          } else {
 797              $querystring = '?';
 798          }
 799  
 800          return strip_querystring(qualified_me()) . $querystring;
 801  
 802      }
 803  }
 804  
 805  /**
 806   * Abstract class for blog_filter objects.
 807   * A set of core filters are implemented here. To write new filters, you need to subclass
 808   * blog_filter and give it the name of the type you want (for example, blog_filter_entry).
 809   * The blog_filter abstract class will automatically use it when the filter is added to the
 810   * URL. The first parameter of the constructor is the ID of your filter, but it can be a string
 811   * or have any other meaning you wish it to have. The second parameter is called $type and is
 812   * used as a sub-type for filters that have a very similar implementation (see blog_filter_context for an example)
 813   */
 814  abstract class blog_filter {
 815      /**
 816       * An array of strings representing the available filter types for each blog_filter.
 817       * @var array $availabletypes
 818       */
 819      public $availabletypes = array();
 820  
 821      /**
 822       * The type of filter (for example, types of blog_filter_context are site, course and module)
 823       * @var string $type
 824       */
 825      public $type;
 826  
 827      /**
 828       * The unique ID for a filter's associated record
 829       * @var int $id
 830       */
 831      public $id;
 832  
 833      /**
 834       * An array of table aliases that are used in the WHERE conditions
 835       * @var array $tables
 836       */
 837      public $tables = array();
 838  
 839      /**
 840       * An array of WHERE conditions
 841       * @var array $conditions
 842       */
 843      public $conditions = array();
 844  
 845      /**
 846       * An array of SQL params
 847       * @var array $params
 848       */
 849      public $params = array();
 850  
 851      /**
 852       * An array of filter types which this particular filter type overrides: their conditions will not be evaluated
 853       */
 854      public $overrides = array();
 855  
 856      public function __construct($id, $type=null) {
 857          $this->id = $id;
 858          $this->type = $type;
 859      }
 860  
 861      /**
 862       * TODO This is poor design. A parent class should not know anything about its children.
 863       * The default case helps to resolve this design issue
 864       */
 865      public static function get_instance($id, $type) {
 866  
 867          switch ($type) {
 868              case 'site':
 869              case 'course':
 870              case 'module':
 871                  return new blog_filter_context($id, $type);
 872                  break;
 873  
 874              case 'group':
 875              case 'user':
 876                  return new blog_filter_user($id, $type);
 877                  break;
 878  
 879              case 'tag':
 880                  return new blog_filter_tag($id);
 881                  break;
 882  
 883              default:
 884                  $classname = "blog_filter_$type";
 885                  if (class_exists($classname)) {
 886                      return new $classname($id, $type);
 887                  }
 888          }
 889      }
 890  }
 891  
 892  /**
 893   * This filter defines the context level of the blog entries being searched: site, course, module
 894   */
 895  class blog_filter_context extends blog_filter {
 896      /**
 897       * Constructor
 898       *
 899       * @param string $type
 900       * @param int    $id
 901       */
 902      public function __construct($id=null, $type='site') {
 903          global $SITE, $CFG, $DB;
 904  
 905          if (empty($id)) {
 906              $this->type = 'site';
 907          } else {
 908              $this->id = $id;
 909              $this->type = $type;
 910          }
 911  
 912          $this->availabletypes = array('site' => get_string('site'),
 913                                        'course' => get_string('course'),
 914                                        'module' => get_string('activity'));
 915  
 916          switch ($this->type) {
 917              case 'course': // Careful of site course!
 918                  // Ignore course filter if blog associations are not enabled.
 919                  if ($this->id != $SITE->id && !empty($CFG->useblogassociations)) {
 920                      $this->overrides = array('site');
 921                      $context = context_course::instance($this->id);
 922                      $this->tables['ba'] = 'blog_association';
 923                      $this->conditions[] = 'p.id = ba.blogid';
 924                      $this->conditions[] = 'ba.contextid = '.$context->id;
 925                      break;
 926                  } else {
 927                      // We are dealing with the site course, do not break from the current case.
 928                  }
 929  
 930              case 'site':
 931                  // No special constraints.
 932                  break;
 933              case 'module':
 934                  if (!empty($CFG->useblogassociations)) {
 935                      $this->overrides = array('course', 'site');
 936  
 937                      $context = context_module::instance($this->id);
 938                      $this->tables['ba'] = 'blog_association';
 939                      $this->tables['p']  = 'post';
 940                      $this->conditions = array('p.id = ba.blogid', 'ba.contextid = ?');
 941                      $this->params = array($context->id);
 942                  }
 943                  break;
 944          }
 945      }
 946  }
 947  
 948  /**
 949   * This filter defines the user level of the blog entries being searched: a userid or a groupid.
 950   * It can be combined with a context filter in order to refine the search.
 951   */
 952  class blog_filter_user extends blog_filter {
 953      public $tables = array('u' => 'user');
 954  
 955      /**
 956       * Constructor
 957       *
 958       * @param string $type
 959       * @param int    $id
 960       */
 961      public function __construct($id=null, $type='user') {
 962          global $CFG, $DB, $USER;
 963          $this->availabletypes = array('user' => get_string('user'), 'group' => get_string('group'));
 964  
 965          if (empty($id)) {
 966              $this->id = $USER->id;
 967              $this->type = 'user';
 968          } else {
 969              $this->id = $id;
 970              $this->type = $type;
 971          }
 972  
 973          if ($this->type == 'user') {
 974              $this->conditions = array('u.id = ?');
 975              $this->params = array($this->id);
 976              $this->overrides = array('group');
 977  
 978          } else if ($this->type == 'group') {
 979              $this->overrides = array('course', 'site');
 980  
 981              $this->tables['gm'] = 'groups_members';
 982              $this->conditions[] = 'p.userid = gm.userid';
 983              $this->conditions[] = 'gm.groupid = ?';
 984              $this->params[]     = $this->id;
 985  
 986              if (!empty($CFG->useblogassociations)) {  // Only show blog entries associated with this course.
 987                  $coursecontext     = context_course::instance($DB->get_field('groups', 'courseid', array('id' => $this->id)));
 988                  $this->tables['ba'] = 'blog_association';
 989                  $this->conditions[] = 'gm.groupid = ?';
 990                  $this->conditions[] = 'ba.contextid = ?';
 991                  $this->conditions[] = 'ba.blogid = p.id';
 992                  $this->params[]     = $this->id;
 993                  $this->params[]     = $coursecontext->id;
 994              }
 995          }
 996  
 997      }
 998  }
 999  
1000  /**
1001   * This filter defines a tag by which blog entries should be searched.
1002   */
1003  class blog_filter_tag extends blog_filter {
1004      public $tables = array('t' => 'tag', 'ti' => 'tag_instance', 'p' => 'post');
1005  
1006      /**
1007       * Constructor
1008       *
1009       * @return void
1010       */
1011      public function __construct($id) {
1012          global $DB;
1013          $this->id = $id;
1014  
1015          $this->conditions = array('ti.tagid = t.id',
1016                                    "ti.itemtype = 'post'",
1017                                    'ti.itemid = p.id',
1018                                    't.id = ?');
1019          $this->params = array($this->id);
1020      }
1021  }
1022  
1023  /**
1024   * This filter defines a specific blog entry id.
1025   */
1026  class blog_filter_entry extends blog_filter {
1027      public $conditions = array('p.id = ?');
1028      public $overrides  = array('site', 'course', 'module', 'group', 'user', 'tag');
1029  
1030      public function __construct($id) {
1031          $this->id = $id;
1032          $this->params[] = $this->id;
1033      }
1034  }
1035  
1036  /**
1037   * This filter restricts the results to a time interval in seconds up to time()
1038   */
1039  class blog_filter_since extends blog_filter {
1040      public function __construct($interval) {
1041          $this->conditions[] = 'p.lastmodified >= ? AND p.lastmodified <= ?';
1042          $this->params[] = time() - $interval;
1043          $this->params[] = time();
1044      }
1045  }
1046  
1047  /**
1048   * Filter used to perform full-text search on an entry's subject, summary and content
1049   */
1050  class blog_filter_search extends blog_filter {
1051  
1052      public function __construct($searchterm) {
1053          global $DB;
1054          $this->conditions = array("(".$DB->sql_like('p.summary', '?', false)." OR
1055                                      ".$DB->sql_like('p.content', '?', false)." OR
1056                                      ".$DB->sql_like('p.subject', '?', false).")");
1057          $this->params[] = "%$searchterm%";
1058          $this->params[] = "%$searchterm%";
1059          $this->params[] = "%$searchterm%";
1060      }
1061  }
1062  
1063  
1064  /**
1065   * Renderable class to represent an entry attachment
1066   */
1067  class blog_entry_attachment implements renderable {
1068  
1069      public $filename;
1070      public $url;
1071      public $file;
1072  
1073      /**
1074       * Gets the file data
1075       *
1076       * @param stored_file $file
1077       * @param int $entryid Attachment entry id
1078       */
1079      public function __construct($file, $entryid) {
1080  
1081          global $CFG;
1082  
1083          $this->file = $file;
1084          $this->filename = $file->get_filename();
1085          $this->url = file_encode_url($CFG->wwwroot . '/pluginfile.php',
1086                                       '/' . SYSCONTEXTID . '/blog/attachment/' . $entryid . '/' . $this->filename);
1087      }
1088  
1089  }