blog/lib.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  * Core global functions for Blog.
  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 /*
  29  * Library of functions and constants for blog
  30  */
  31 require_once($CFG->dirroot .'/blog/rsslib.php');
  32 require_once($CFG->dirroot.'/tag/lib.php');
  33
  34 /**
  35  * User can edit a blog entry if this is their own blog entry and they have
  36  * the capability moodle/blog:create, or if they have the capability
  37  * moodle/blog:manageentries.
  38  *
  39  * This also applies to deleting of entries.
  40  */
  41 function blog_user_can_edit_entry($blogentry) {
  42     global $USER;
  43
  44     $sitecontext = context_system::instance();
  45
  46     if (has_capability('moodle/blog:manageentries', $sitecontext)) {
  47         return true; // Can edit any blog entry.
  48     }
  49
  50     if ($blogentry->userid == $USER->id && has_capability('moodle/blog:create', $sitecontext)) {
  51         return true; // Can edit own when having blog:create capability.
  52     }
  53
  54     return false;
  55 }
  56
  57
  58 /**
  59  * Checks to see if a user can view the blogs of another user.
  60  * Only blog level is checked here, the capabilities are enforced
  61  * in blog/index.php
  62  */
  63 function blog_user_can_view_user_entry($targetuserid, $blogentry=null) {
  64     global $CFG, $USER, $DB;
  65
  66     if (empty($CFG->enableblogs)) {
  67         return false; // Blog system disabled.
  68     }
  69
  70     if (isloggedin() && $USER->id == $targetuserid) {
  71         return true; // Can view own entries in any case.
  72     }
  73
  74     $sitecontext = context_system::instance();
  75     if (has_capability('moodle/blog:manageentries', $sitecontext)) {
  76         return true; // Can manage all entries.
  77     }
  78
  79     // If blog is in draft state, then make sure user have proper capability.
  80     if ($blogentry && $blogentry->publishstate == 'draft' && !has_capability('moodle/blog:viewdrafts', $sitecontext)) {
  81         return false;  // Can not view draft of others.
  82     }
  83
  84     // If blog entry is not public, make sure user is logged in.
  85     if ($blogentry && $blogentry->publishstate != 'public' && !isloggedin()) {
  86         return false;
  87     }
  88
  89     // If blogentry is not passed or all above checks pass, then check capability based on system config.
  90     switch ($CFG->bloglevel) {
  91         case BLOG_GLOBAL_LEVEL:
  92             return true;
  93         break;
  94
  95         case BLOG_SITE_LEVEL:
  96             if (isloggedin()) { // Not logged in viewers forbidden.
  97                 return true;
  98             }
  99             return false;
 100         break;
 101
 102         case BLOG_USER_LEVEL:
 103         default:
 104             // If user is viewing other user blog, then user should have user:readuserblogs capability.
 105             $personalcontext = context_user::instance($targetuserid);
 106             return has_capability('moodle/user:readuserblogs', $personalcontext);
 107         break;
 108
 109     }
 110 }
 111
 112 /**
 113  * remove all associations for the blog entries of a particular user
 114  * @param int userid - id of user whose blog associations will be deleted
 115  */
 116 function blog_remove_associations_for_user($userid) {
 117     global $DB;
 118     throw new coding_exception('function blog_remove_associations_for_user() is not finished');
 119     /*
 120     $blogentries = blog_fetch_entries(array('user' => $userid), 'lasmodified DESC');
 121     foreach ($blogentries as $entry) {
 122         if (blog_user_can_edit_entry($entry)) {
 123             blog_remove_associations_for_entry($entry->id);
 124         }
 125     }
 126      */
 127 }
 128
 129 /**
 130  * remove all associations for the blog entries of a particular course
 131  * @param int courseid - id of user whose blog associations will be deleted
 132  */
 133 function blog_remove_associations_for_course($courseid) {
 134     global $DB;
 135     $context = context_course::instance($courseid);
 136     $DB->delete_records('blog_association', array('contextid' => $context->id));
 137 }
 138
 139 /**
 140  * Given a record in the {blog_external} table, checks the blog's URL
 141  * for new entries not yet copied into Moodle.
 142  * Also attempts to identify and remove deleted blog entries
 143  *
 144  * @param object $externalblog
 145  * @return boolean False if the Feed is invalid
 146  */
 147 function blog_sync_external_entries($externalblog) {
 148     global $CFG, $DB;
 149     require_once($CFG->libdir . '/simplepie/moodle_simplepie.php');
 150
 151     $rss = new moodle_simplepie();
 152     $rssfile = $rss->registry->create('File', array($externalblog->url));
 153     $filetest = $rss->registry->create('Locator', array($rssfile));
 154
 155     if (!$filetest->is_feed($rssfile)) {
 156         $externalblog->failedlastsync = 1;
 157         $DB->update_record('blog_external', $externalblog);
 158         return false;
 159     } else if (!empty($externalblog->failedlastsync)) {
 160         $externalblog->failedlastsync = 0;
 161         $DB->update_record('blog_external', $externalblog);
 162     }
 163
 164     $rss->set_feed_url($externalblog->url);
 165     $rss->init();
 166
 167     if (empty($rss->data)) {
 168         return null;
 169     }
 170     // Used to identify blog posts that have been deleted from the source feed.
 171     $oldesttimestamp = null;
 172     $uniquehashes = array();
 173
 174     foreach ($rss->get_items() as $entry) {
 175         // If filtertags are defined, use them to filter the entries by RSS category.
 176         if (!empty($externalblog->filtertags)) {
 177             $containsfiltertag = false;
 178             $categories = $entry->get_categories();
 179             $filtertags = explode(',', $externalblog->filtertags);
 180             $filtertags = array_map('trim', $filtertags);
 181             $filtertags = array_map('strtolower', $filtertags);
 182
 183             if (!empty($categories)) {
 184                 foreach ($categories as $category) {
 185                     if (in_array(trim(strtolower($category->term)), $filtertags)) {
 186                         $containsfiltertag = true;
 187                     }
 188                 }
 189             }
 190
 191             if (!$containsfiltertag) {
 192                 continue;
 193             }
 194         }
 195
 196         $uniquehashes[] = $entry->get_permalink();
 197
 198         $newentry = new stdClass();
 199         $newentry->userid = $externalblog->userid;
 200         $newentry->module = 'blog_external';
 201         $newentry->content = $externalblog->id;
 202         $newentry->uniquehash = $entry->get_permalink();
 203         $newentry->publishstate = 'site';
 204         $newentry->format = FORMAT_HTML;
 205         // Clean subject of html, just in case.
 206         $newentry->subject = clean_param($entry->get_title(), PARAM_TEXT);
 207         // Observe 128 max chars in DB.
 208         // TODO: +1 to raise this to 255.
 209         if (core_text::strlen($newentry->subject) > 128) {
 210             $newentry->subject = core_text::substr($newentry->subject, 0, 125) . '...';
 211         }
 212         $newentry->summary = $entry->get_description();
 213
 214         // Used to decide whether to insert or update.
 215         // Uses enty permalink plus creation date if available.
 216         $existingpostconditions = array('uniquehash' => $entry->get_permalink());
 217
 218         // Our DB doesnt allow null creation or modified timestamps so check the external blog supplied one.
 219         $entrydate = $entry->get_date('U');
 220         if (!empty($entrydate)) {
 221             $existingpostconditions['created'] = $entrydate;
 222         }
 223
 224         // The post ID or false if post not found in DB.
 225         $postid = $DB->get_field('post', 'id', $existingpostconditions);
 226
 227         $timestamp = null;
 228         if (empty($entrydate)) {
 229             $timestamp = time();
 230         } else {
 231             $timestamp = $entrydate;
 232         }
 233
 234         // Only set created if its a new post so we retain the original creation timestamp if the post is edited.
 235         if ($postid === false) {
 236             $newentry->created = $timestamp;
 237         }
 238         $newentry->lastmodified = $timestamp;
 239
 240         if (empty($oldesttimestamp) || $timestamp < $oldesttimestamp) {
 241             // Found an older post.
 242             $oldesttimestamp = $timestamp;
 243         }
 244
 245         if (core_text::strlen($newentry->uniquehash) > 255) {
 246             // The URL for this item is too long for the field. Rather than add
 247             // the entry without the link we will skip straight over it.
 248             // RSS spec says recommended length 500, we use 255.
 249             debugging('External blog entry skipped because of oversized URL', DEBUG_DEVELOPER);
 250             continue;
 251         }
 252
 253         if ($postid === false) {
 254             $id = $DB->insert_record('post', $newentry);
 255
 256             // Set tags.
 257             if ($tags = tag_get_tags_array('blog_external', $externalblog->id)) {
 258                 tag_set('post', $id, $tags, 'core', context_user::instance($externalblog->userid)->id);
 259             }
 260         } else {
 261             $newentry->id = $postid;
 262             $DB->update_record('post', $newentry);
 263         }
 264     }
 265
 266     // Look at the posts we have in the database to check if any of them have been deleted from the feed.
 267     // Only checking posts within the time frame returned by the rss feed. Older items may have been deleted or
 268     // may just not be returned anymore. We can't tell the difference so we leave older posts alone.
 269     $sql = "SELECT id, uniquehash
 270               FROM {post}
 271              WHERE module = 'blog_external'
 272                    AND " . $DB->sql_compare_text('content') . " = " . $DB->sql_compare_text(':blogid') . "
 273                    AND created > :ts";
 274     $dbposts = $DB->get_records_sql($sql, array('blogid' => $externalblog->id, 'ts' => $oldesttimestamp));
 275
 276     $todelete = array();
 277     foreach ($dbposts as $dbpost) {
 278         if ( !in_array($dbpost->uniquehash, $uniquehashes) ) {
 279             $todelete[] = $dbpost->id;
 280         }
 281     }
 282     $DB->delete_records_list('post', 'id', $todelete);
 283
 284     $DB->update_record('blog_external', array('id' => $externalblog->id, 'timefetched' => time()));
 285 }
 286
 287 /**
 288  * Given an external blog object, deletes all related blog entries from the post table.
 289  * NOTE: The external blog's id is saved as post.content, a field that is not oterhwise used by blog entries.
 290  * @param object $externablog
 291  */
 292 function blog_delete_external_entries($externalblog) {
 293     global $DB;
 294     require_capability('moodle/blog:manageexternal', context_system::instance());
 295     $DB->delete_records_select('post',
 296                                "module='blog_external' AND " . $DB->sql_compare_text('content') . " = ?",
 297                                array($externalblog->id));
 298 }
 299
 300 /**
 301  * This function checks that blogs are enabled, and that the user can see blogs at all
 302  * @return bool
 303  */
 304 function blog_is_enabled_for_user() {
 305     global $CFG;
 306     return (!empty($CFG->enableblogs) && (isloggedin() || ($CFG->bloglevel == BLOG_GLOBAL_LEVEL)));
 307 }
 308
 309 /**
 310  * This function gets all of the options available for the current user in respect
 311  * to blogs.
 312  *
 313  * It loads the following if applicable:
 314  * -  Module options {@see blog_get_options_for_module}
 315  * -  Course options {@see blog_get_options_for_course}
 316  * -  User specific options {@see blog_get_options_for_user}
 317  * -  General options (BLOG_LEVEL_GLOBAL)
 318  *
 319  * @param moodle_page $page The page to load for (normally $PAGE)
 320  * @param stdClass $userid Load for a specific user
 321  * @return array An array of options organised by type.
 322  */
 323 function blog_get_all_options(moodle_page $page, stdClass $userid = null) {
 324     global $CFG, $DB, $USER;
 325
 326     $options = array();
 327
 328     // If blogs are enabled and the user is logged in and not a guest.
 329     if (blog_is_enabled_for_user()) {
 330         // If the context is the user then assume we want to load for the users context.
 331         if (is_null($userid) && $page->context->contextlevel == CONTEXT_USER) {
 332             $userid = $page->context->instanceid;
 333         }
 334         // Check the userid var.
 335         if (!is_null($userid) && $userid!==$USER->id) {
 336             // Load the user from the userid... it MUST EXIST throw a wobbly if it doesn't!
 337             $user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
 338         } else {
 339             $user = null;
 340         }
 341
 342         if ($CFG->useblogassociations && $page->cm !== null) {
 343             // Load for the module associated with the page.
 344             $options[CONTEXT_MODULE] = blog_get_options_for_module($page->cm, $user);
 345         } else if ($CFG->useblogassociations && $page->course->id != SITEID) {
 346             // Load the options for the course associated with the page.
 347             $options[CONTEXT_COURSE] = blog_get_options_for_course($page->course, $user);
 348         }
 349
 350         // Get the options for the user.
 351         if ($user !== null and !isguestuser($user)) {
 352             // Load for the requested user.
 353             $options[CONTEXT_USER+1] = blog_get_options_for_user($user);
 354         }
 355         // Load for the current user.
 356         if (isloggedin() and !isguestuser()) {
 357             $options[CONTEXT_USER] = blog_get_options_for_user();
 358         }
 359     }
 360
 361     // If blog level is global then display a link to view all site entries.
 362     if (!empty($CFG->enableblogs)
 363         && $CFG->bloglevel >= BLOG_GLOBAL_LEVEL
 364         && has_capability('moodle/blog:view', context_system::instance())) {
 365
 366         $options[CONTEXT_SYSTEM] = array('viewsite' => array(
 367             'string' => get_string('viewsiteentries', 'blog'),
 368             'link' => new moodle_url('/blog/index.php')
 369         ));
 370     }
 371
 372     // Return the options.
 373     return $options;
 374 }
 375
 376 /**
 377  * Get all of the blog options that relate to the passed user.
 378  *
 379  * If no user is passed the current user is assumed.
 380  *
 381  * @staticvar array $useroptions Cache so we don't have to regenerate multiple times
 382  * @param stdClass $user
 383  * @return array The array of options for the requested user
 384  */
 385 function blog_get_options_for_user(stdClass $user=null) {
 386     global $CFG, $USER;
 387     // Cache.
 388     static $useroptions = array();
 389
 390     $options = array();
 391     // Blogs must be enabled and the user must be logged in.
 392     if (!blog_is_enabled_for_user()) {
 393         return $options;
 394     }
 395
 396     // Sort out the user var.
 397     if ($user === null || $user->id == $USER->id) {
 398         $user = $USER;
 399         $iscurrentuser = true;
 400     } else {
 401         $iscurrentuser = false;
 402     }
 403
 404     // If we've already generated serve from the cache.
 405     if (array_key_exists($user->id, $useroptions)) {
 406         return $useroptions[$user->id];
 407     }
 408
 409     $sitecontext = context_system::instance();
 410     $canview = has_capability('moodle/blog:view', $sitecontext);
 411
 412     if (!$iscurrentuser && $canview && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 413         // Not the current user, but we can view and its blogs are enabled for SITE or GLOBAL.
 414         $options['userentries'] = array(
 415             'string' => get_string('viewuserentries', 'blog', fullname($user)),
 416             'link' => new moodle_url('/blog/index.php', array('userid'=>$user->id))
 417         );
 418     } else {
 419         // It's the current user.
 420         if ($canview) {
 421             // We can view our own blogs .... BIG surprise.
 422             $options['view'] = array(
 423                 'string' => get_string('viewallmyentries', 'blog'),
 424                 'link' => new moodle_url('/blog/index.php', array('userid'=>$USER->id))
 425             );
 426         }
 427         if (has_capability('moodle/blog:create', $sitecontext)) {
 428             // We can add to our own blog.
 429             $options['add'] = array(
 430                 'string' => get_string('addnewentry', 'blog'),
 431                 'link' => new moodle_url('/blog/edit.php', array('action'=>'add'))
 432             );
 433         }
 434     }
 435     if ($canview && $CFG->enablerssfeeds) {
 436         $options['rss'] = array(
 437             'string' => get_string('rssfeed', 'blog'),
 438             'link' => new moodle_url(rss_get_url($sitecontext->id, $USER->id, 'blog', 'user/'.$user->id))
 439         );
 440     }
 441
 442     // Cache the options.
 443     $useroptions[$user->id] = $options;
 444     // Return the options.
 445     return $options;
 446 }
 447
 448 /**
 449  * Get the blog options that relate to the given course for the given user.
 450  *
 451  * @staticvar array $courseoptions A cache so we can save regenerating multiple times
 452  * @param stdClass $course The course to load options for
 453  * @param stdClass $user The user to load options for null == current user
 454  * @return array The array of options
 455  */
 456 function blog_get_options_for_course(stdClass $course, stdClass $user=null) {
 457     global $CFG, $USER;
 458     // Cache.
 459     static $courseoptions = array();
 460
 461     $options = array();
 462
 463     // User must be logged in and blogs must be enabled.
 464     if (!blog_is_enabled_for_user()) {
 465         return $options;
 466     }
 467
 468     // Check that the user can associate with the course.
 469     $sitecontext = context_system::instance();
 470     // Generate the cache key.
 471     $key = $course->id.':';
 472     if (!empty($user)) {
 473         $key .= $user->id;
 474     } else {
 475         $key .= $USER->id;
 476     }
 477     // Serve from the cache if we've already generated for this course.
 478     if (array_key_exists($key, $courseoptions)) {
 479         return $courseoptions[$key];
 480     }
 481
 482     if (has_capability('moodle/blog:view', $sitecontext)) {
 483         // We can view!
 484         if ($CFG->bloglevel >= BLOG_SITE_LEVEL) {
 485             // View entries about this course.
 486             $options['courseview'] = array(
 487                 'string' => get_string('viewcourseblogs', 'blog'),
 488                 'link' => new moodle_url('/blog/index.php', array('courseid' => $course->id))
 489             );
 490         }
 491         // View MY entries about this course.
 492         $options['courseviewmine'] = array(
 493             'string' => get_string('viewmyentriesaboutcourse', 'blog'),
 494             'link' => new moodle_url('/blog/index.php', array('courseid' => $course->id, 'userid' => $USER->id))
 495         );
 496         if (!empty($user) && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 497             // View the provided users entries about this course.
 498             $options['courseviewuser'] = array(
 499                 'string' => get_string('viewentriesbyuseraboutcourse', 'blog', fullname($user)),
 500                 'link' => new moodle_url('/blog/index.php', array('courseid' => $course->id, 'userid' => $user->id))
 501             );
 502         }
 503     }
 504
 505     if (has_capability('moodle/blog:create', $sitecontext)) {
 506         // We can blog about this course.
 507         $options['courseadd'] = array(
 508             'string' => get_string('blogaboutthiscourse', 'blog'),
 509             'link' => new moodle_url('/blog/edit.php', array('action' => 'add', 'courseid' => $course->id))
 510         );
 511     }
 512
 513     // Cache the options for this course.
 514     $courseoptions[$key] = $options;
 515     // Return the options.
 516     return $options;
 517 }
 518
 519 /**
 520  * Get the blog options relating to the given module for the given user
 521  *
 522  * @staticvar array $moduleoptions Cache
 523  * @param stdClass|cm_info $module The module to get options for
 524  * @param stdClass $user The user to get options for null == currentuser
 525  * @return array
 526  */
 527 function blog_get_options_for_module($module, $user=null) {
 528     global $CFG, $USER;
 529     // Cache.
 530     static $moduleoptions = array();
 531
 532     $options = array();
 533     // User must be logged in, blogs must be enabled.
 534     if (!blog_is_enabled_for_user()) {
 535         return $options;
 536     }
 537
 538     $sitecontext = context_system::instance();
 539
 540     // Generate the cache key.
 541     $key = $module->id.':';
 542     if (!empty($user)) {
 543         $key .= $user->id;
 544     } else {
 545         $key .= $USER->id;
 546     }
 547     if (array_key_exists($key, $moduleoptions)) {
 548         // Serve from the cache so we don't have to regenerate.
 549         return $moduleoptions[$key];
 550     }
 551
 552     if (has_capability('moodle/blog:view', $sitecontext)) {
 553         // Save correct module name for later usage.
 554         $modulename = get_string('modulename', $module->modname);
 555
 556         // We can view!
 557         if ($CFG->bloglevel >= BLOG_SITE_LEVEL) {
 558             // View all entries about this module.
 559             $a = new stdClass;
 560             $a->type = $modulename;
 561             $options['moduleview'] = array(
 562                 'string' => get_string('viewallmodentries', 'blog', $a),
 563                 'link' => new moodle_url('/blog/index.php', array('modid'=>$module->id))
 564             );
 565         }
 566         // View MY entries about this module.
 567         $options['moduleviewmine'] = array(
 568             'string' => get_string('viewmyentriesaboutmodule', 'blog', $modulename),
 569             'link' => new moodle_url('/blog/index.php', array('modid'=>$module->id, 'userid'=>$USER->id))
 570         );
 571         if (!empty($user) && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 572             // View the given users entries about this module.
 573             $a = new stdClass;
 574             $a->mod = $modulename;
 575             $a->user = fullname($user);
 576             $options['moduleviewuser'] = array(
 577                 'string' => get_string('blogentriesbyuseraboutmodule', 'blog', $a),
 578                 'link' => new moodle_url('/blog/index.php', array('modid'=>$module->id, 'userid'=>$user->id))
 579             );
 580         }
 581     }
 582
 583     if (has_capability('moodle/blog:create', $sitecontext)) {
 584         // The user can blog about this module.
 585         $options['moduleadd'] = array(
 586             'string' => get_string('blogaboutthismodule', 'blog', $modulename),
 587             'link' => new moodle_url('/blog/edit.php', array('action'=>'add', 'modid'=>$module->id))
 588         );
 589     }
 590     // Cache the options.
 591     $moduleoptions[$key] = $options;
 592     // Return the options.
 593     return $options;
 594 }
 595
 596 /**
 597  * This function encapsulates all the logic behind the complex
 598  * navigation, titles and headings of the blog listing page, depending
 599  * on URL params. It looks at URL params and at the current context level.
 600  * It builds and returns an array containing:
 601  *
 602  * 1. heading: The heading displayed above the blog entries
 603  * 2. stradd:  The text to be used as the "Add entry" link
 604  * 3. strview: The text to be used as the "View entries" link
 605  * 4. url:     The moodle_url object used as the base for add and view links
 606  * 5. filters: An array of parameters used to filter blog listings. Used by index.php and the Recent blogs block
 607  *
 608  * All other variables are set directly in $PAGE
 609  *
 610  * It uses the current URL to build these variables.
 611  * A number of mutually exclusive use cases are used to structure this function.
 612  *
 613  * @return array
 614  */
 615 function blog_get_headers($courseid=null, $groupid=null, $userid=null, $tagid=null) {
 616     global $CFG, $PAGE, $DB, $USER;
 617
 618     $id       = optional_param('id', null, PARAM_INT);
 619     $tag      = optional_param('tag', null, PARAM_NOTAGS);
 620     $tagid    = optional_param('tagid', $tagid, PARAM_INT);
 621     $userid   = optional_param('userid', $userid, PARAM_INT);
 622     $modid    = optional_param('modid', null, PARAM_INT);
 623     $entryid  = optional_param('entryid', null, PARAM_INT);
 624     $groupid  = optional_param('groupid', $groupid, PARAM_INT);
 625     $courseid = optional_param('courseid', $courseid, PARAM_INT);
 626     $search   = optional_param('search', null, PARAM_RAW);
 627     $action   = optional_param('action', null, PARAM_ALPHA);
 628     $confirm  = optional_param('confirm', false, PARAM_BOOL);
 629
 630     // Ignore userid when action == add.
 631     if ($action == 'add' && $userid) {
 632         unset($userid);
 633         $PAGE->url->remove_params(array('userid'));
 634     } else if ($action == 'add' && $entryid) {
 635         unset($entryid);
 636         $PAGE->url->remove_params(array('entryid'));
 637     }
 638
 639     $headers = array('title' => '', 'heading' => '', 'cm' => null, 'filters' => array());
 640
 641     $blogurl = new moodle_url('/blog/index.php');
 642
 643     $headers['stradd'] = get_string('addnewentry', 'blog');
 644     $headers['strview'] = null;
 645
 646     $site = $DB->get_record('course', array('id' => SITEID));
 647     $sitecontext = context_system::instance();
 648     // Common Lang strings.
 649     $strparticipants = get_string("participants");
 650     $strblogentries  = get_string("blogentries", 'blog');
 651
 652     // Prepare record objects as needed.
 653     if (!empty($courseid)) {
 654         $headers['filters']['course'] = $courseid;
 655         $course = $DB->get_record('course', array('id' => $courseid));
 656     }
 657
 658     if (!empty($userid)) {
 659         $headers['filters']['user'] = $userid;
 660         $user = $DB->get_record('user', array('id' => $userid));
 661     }
 662
 663     if (!empty($groupid)) { // The groupid always overrides courseid.
 664         $headers['filters']['group'] = $groupid;
 665         $group = $DB->get_record('groups', array('id' => $groupid));
 666         $course = $DB->get_record('course', array('id' => $group->courseid));
 667     }
 668
 669     $PAGE->set_pagelayout('standard');
 670
 671     // The modid always overrides courseid, so the $course object may be reset here.
 672     if (!empty($modid) && $CFG->useblogassociations) {
 673
 674         $headers['filters']['module'] = $modid;
 675         // A groupid param may conflict with this coursemod's courseid. Ignore groupid in that case.
 676         $courseid = $DB->get_field('course_modules', 'course', array('id'=>$modid));
 677         $course = $DB->get_record('course', array('id' => $courseid));
 678         $cm = $DB->get_record('course_modules', array('id' => $modid));
 679         $cm->modname = $DB->get_field('modules', 'name', array('id' => $cm->module));
 680         $cm->name = $DB->get_field($cm->modname, 'name', array('id' => $cm->instance));
 681         $a = new stdClass();
 682         $a->type = get_string('modulename', $cm->modname);
 683         $PAGE->set_cm($cm, $course);
 684         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 685         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 686     }
 687
 688     // Case 1: No entry, mod, course or user params: all site entries to be shown (filtered by search and tag/tagid)
 689     // Note: if action is set to 'add' or 'edit', we do this at the end.
 690     if (empty($entryid) && empty($modid) && empty($courseid) && empty($userid) && !in_array($action, array('edit', 'add'))) {
 691         $shortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 692         $PAGE->navbar->add($strblogentries, $blogurl);
 693         $PAGE->set_title("$shortname: " . get_string('blog', 'blog'));
 694         $PAGE->set_heading("$shortname: " . get_string('blog', 'blog'));
 695         $headers['heading'] = get_string('siteblog', 'blog', $shortname);
 696     }
 697
 698     // Case 2: only entryid is requested, ignore all other filters. courseid is used to give more contextual information.
 699     if (!empty($entryid)) {
 700         $headers['filters']['entry'] = $entryid;
 701         $sql = 'SELECT u.* FROM {user} u, {post} p WHERE p.id = ? AND p.userid = u.id';
 702         $user = $DB->get_record_sql($sql, array($entryid));
 703         $entry = $DB->get_record('post', array('id' => $entryid));
 704
 705         $blogurl->param('userid', $user->id);
 706
 707         if (!empty($course)) {
 708             $mycourseid = $course->id;
 709             $blogurl->param('courseid', $mycourseid);
 710         } else {
 711             $mycourseid = $site->id;
 712         }
 713         $shortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 714
 715         $PAGE->navbar->add($strblogentries, $blogurl);
 716
 717         $blogurl->remove_params('userid');
 718         $PAGE->navbar->add($entry->subject, $blogurl);
 719         $PAGE->set_title("$shortname: " . fullname($user) . ": $entry->subject");
 720         $PAGE->set_heading("$shortname: " . fullname($user) . ": $entry->subject");
 721         $headers['heading'] = get_string('blogentrybyuser', 'blog', fullname($user));
 722
 723         // We ignore tag and search params.
 724         if (empty($action) || !$CFG->useblogassociations) {
 725             $headers['url'] = $blogurl;
 726             return $headers;
 727         }
 728     }
 729
 730     if (!empty($userid) && empty($entryid) && ((empty($courseid) && empty($modid)) || !$CFG->useblogassociations)) {
 731         // Case 3: A user's blog entries.
 732
 733         $shortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 734         $blogurl->param('userid', $userid);
 735         $PAGE->set_title("$shortname: " . fullname($user) . ": " . get_string('blog', 'blog'));
 736         $PAGE->set_heading("$shortname: " . fullname($user) . ": " . get_string('blog', 'blog'));
 737         $headers['heading'] = get_string('userblog', 'blog', fullname($user));
 738         $headers['strview'] = get_string('viewuserentries', 'blog', fullname($user));
 739
 740     } else if (!$CFG->useblogassociations && empty($userid) && !in_array($action, array('edit', 'add'))) {
 741         // Case 4: No blog associations, no userid.
 742
 743         $shortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 744         $PAGE->set_title("$shortname: " . get_string('blog', 'blog'));
 745         $PAGE->set_heading("$shortname: " . get_string('blog', 'blog'));
 746         $headers['heading'] = get_string('siteblog', 'blog', $shortname);
 747     } else if (!empty($userid) && !empty($modid) && empty($entryid)) {
 748         // Case 5: Blog entries associated with an activity by a specific user (courseid ignored).
 749
 750         $shortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 751         $blogurl->param('userid', $userid);
 752         $blogurl->param('modid', $modid);
 753
 754         // Course module navigation is handled by build_navigation as the second param.
 755         $headers['cm'] = $cm;
 756         $PAGE->navbar->add(fullname($user), "$CFG->wwwroot/user/view.php?id=$user->id");
 757         $PAGE->navbar->add($strblogentries, $blogurl);
 758
 759         $PAGE->set_title("$shortname: $cm->name: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 760         $PAGE->set_heading("$shortname: $cm->name: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 761
 762         $a = new stdClass();
 763         $a->user = fullname($user);
 764         $a->mod = $cm->name;
 765         $a->type = get_string('modulename', $cm->modname);
 766         $headers['heading'] = get_string('blogentriesbyuseraboutmodule', 'blog', $a);
 767         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 768         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 769     } else if (!empty($userid) && !empty($courseid) && empty($modid) && empty($entryid)) {
 770         // Case 6: Blog entries associated with a course by a specific user.
 771
 772         $siteshortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 773         $courseshortname = format_string($course->shortname, true, array('context' => context_course::instance($course->id)));
 774         $blogurl->param('userid', $userid);
 775         $blogurl->param('courseid', $courseid);
 776
 777         $PAGE->navbar->add($strblogentries, $blogurl);
 778
 779         $PAGE->set_title("$siteshortname: $courseshortname: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 780         $PAGE->set_heading("$siteshortname: $courseshortname: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 781
 782         $a = new stdClass();
 783         $a->user = fullname($user);
 784         $a->course = format_string($course->fullname, true, array('context' => context_course::instance($course->id)));
 785         $a->type = get_string('course');
 786         $headers['heading'] = get_string('blogentriesbyuseraboutcourse', 'blog', $a);
 787         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 788         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 789
 790         // Remove the userid from the URL to inform the blog_menu block correctly.
 791         $blogurl->remove_params(array('userid'));
 792     } else if (!empty($groupid) && empty($modid) && empty($entryid)) {
 793         // Case 7: Blog entries by members of a group, associated with that group's course.
 794
 795         $siteshortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 796         $courseshortname = format_string($course->shortname, true, array('context' => context_course::instance($course->id)));
 797         $blogurl->param('courseid', $course->id);
 798
 799         $PAGE->navbar->add($strblogentries, $blogurl);
 800         $blogurl->remove_params(array('courseid'));
 801         $blogurl->param('groupid', $groupid);
 802         $PAGE->navbar->add($group->name, $blogurl);
 803
 804         $PAGE->set_title("$siteshortname: $courseshortname: " . get_string('blogentries', 'blog') . ": $group->name");
 805         $PAGE->set_heading("$siteshortname: $courseshortname: " . get_string('blogentries', 'blog') . ": $group->name");
 806
 807         $a = new stdClass();
 808         $a->group = $group->name;
 809         $a->course = format_string($course->fullname, true, array('context' => context_course::instance($course->id)));
 810         $a->type = get_string('course');
 811         $headers['heading'] = get_string('blogentriesbygroupaboutcourse', 'blog', $a);
 812         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 813         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 814     } else if (!empty($groupid) && !empty($modid) && empty($entryid)) {
 815         // Case 8: Blog entries by members of a group, associated with an activity in that course.
 816
 817         $siteshortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 818         $courseshortname = format_string($course->shortname, true, array('context' => context_course::instance($course->id)));
 819         $headers['cm'] = $cm;
 820         $blogurl->param('modid', $modid);
 821         $PAGE->navbar->add($strblogentries, $blogurl);
 822
 823         $blogurl->param('groupid', $groupid);
 824         $PAGE->navbar->add($group->name, $blogurl);
 825
 826         $PAGE->set_title("$siteshortname: $courseshortname: $cm->name: " . get_string('blogentries', 'blog') . ": $group->name");
 827         $PAGE->set_heading("$siteshortname: $courseshortname: $cm->name: " . get_string('blogentries', 'blog') . ": $group->name");
 828
 829         $a = new stdClass();
 830         $a->group = $group->name;
 831         $a->mod = $cm->name;
 832         $a->type = get_string('modulename', $cm->modname);
 833         $headers['heading'] = get_string('blogentriesbygroupaboutmodule', 'blog', $a);
 834         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 835         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 836
 837     } else if (!empty($modid) && empty($userid) && empty($groupid) && empty($entryid)) {
 838         // Case 9: All blog entries associated with an activity.
 839
 840         $siteshortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 841         $courseshortname = format_string($course->shortname, true, array('context' => context_course::instance($course->id)));
 842         $PAGE->set_cm($cm, $course);
 843         $blogurl->param('modid', $modid);
 844         $PAGE->navbar->add($strblogentries, $blogurl);
 845         $PAGE->set_title("$siteshortname: $courseshortname: $cm->name: " . get_string('blogentries', 'blog'));
 846         $PAGE->set_heading("$siteshortname: $courseshortname: $cm->name: " . get_string('blogentries', 'blog'));
 847         $headers['heading'] = get_string('blogentriesabout', 'blog', $cm->name);
 848         $a = new stdClass();
 849         $a->type = get_string('modulename', $cm->modname);
 850         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 851         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 852     } else if (!empty($courseid) && empty($userid) && empty($groupid) && empty($modid) && empty($entryid)) {
 853         // Case 10: All blog entries associated with a course.
 854
 855         $siteshortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 856         $courseshortname = format_string($course->shortname, true, array('context' => context_course::instance($course->id)));
 857         $blogurl->param('courseid', $courseid);
 858         $PAGE->navbar->add($strblogentries, $blogurl);
 859         $PAGE->set_title("$siteshortname: $courseshortname: " . get_string('blogentries', 'blog'));
 860         $PAGE->set_heading("$siteshortname: $courseshortname: " . get_string('blogentries', 'blog'));
 861         $a = new stdClass();
 862         $a->type = get_string('course');
 863         $headers['heading'] = get_string('blogentriesabout',
 864                                          'blog',
 865                                          format_string($course->fullname,
 866                                                        true,
 867                                                        array('context' => context_course::instance($course->id))));
 868         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 869         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 870         $blogurl->remove_params(array('userid'));
 871     }
 872
 873     if (!in_array($action, array('edit', 'add'))) {
 874         // Append Tag info.
 875         if (!empty($tagid)) {
 876             $headers['filters']['tag'] = $tagid;
 877             $blogurl->param('tagid', $tagid);
 878             $tagrec = $DB->get_record('tag', array('id'=>$tagid));
 879             $PAGE->navbar->add($tagrec->name, $blogurl);
 880         } else if (!empty($tag)) {
 881             if ($tagrec = $DB->get_record('tag', array('name' => $tag))) {
 882                 $tagid = $tagrec->id;
 883                 $headers['filters']['tag'] = $tagid;
 884                 $blogurl->param('tag', $tag);
 885                 $PAGE->navbar->add(get_string('tagparam', 'blog', $tag), $blogurl);
 886             }
 887         }
 888
 889         // Append Search info.
 890         if (!empty($search)) {
 891             $headers['filters']['search'] = $search;
 892             $blogurl->param('search', $search);
 893             $PAGE->navbar->add(get_string('searchterm', 'blog', $search), $blogurl->out());
 894         }
 895     }
 896
 897     // Append edit mode info.
 898     if (!empty($action) && $action == 'add') {
 899
 900     } else if (!empty($action) && $action == 'edit') {
 901         $PAGE->navbar->add(get_string('editentry', 'blog'));
 902     }
 903
 904     if (empty($headers['url'])) {
 905         $headers['url'] = $blogurl;
 906     }
 907     return $headers;
 908 }
 909
 910 /**
 911  * Shortcut function for getting a count of blog entries associated with a course or a module
 912  * @param int $courseid The ID of the course
 913  * @param int $cmid The ID of the course_modules
 914  * @return string The number of associated entries
 915  */
 916 function blog_get_associated_count($courseid, $cmid=null) {
 917     global $DB;
 918     $context = context_course::instance($courseid);
 919     if ($cmid) {
 920         $context = context_module::instance($cmid);
 921     }
 922     return $DB->count_records('blog_association', array('contextid' => $context->id));
 923 }
 924
 925 /**
 926  * Running addtional permission check on plugin, for example, plugins
 927  * may have switch to turn on/off comments option, this callback will
 928  * affect UI display, not like pluginname_comment_validate only throw
 929  * exceptions.
 930  * blog_comment_validate will be called before viewing/adding/deleting
 931  * comment, so don't repeat checks.
 932  * Capability check has been done in comment->check_permissions(), we
 933  * don't need to do it again here.
 934  *
 935  * @package  core_blog
 936  * @category comment
 937  *
 938  * @param stdClass $comment_param {
 939  *              context  => context the context object
 940  *              courseid => int course id
 941  *              cm       => stdClass course module object
 942  *              commentarea => string comment area
 943  *              itemid      => int itemid
 944  * }
 945  * @return array
 946  */
 947 function blog_comment_permissions($comment_param) {
 948     global $DB;
 949
 950     // If blog is public and current user is guest, then don't let him post comments.
 951     $blogentry = $DB->get_record('post', array('id' => $comment_param->itemid), 'publishstate', MUST_EXIST);
 952
 953     if ($blogentry->publishstate != 'public') {
 954         if (!isloggedin() || isguestuser()) {
 955             return array('post' => false, 'view' => true);
 956         }
 957     }
 958     return array('post' => true, 'view' => true);
 959 }
 960
 961 /**
 962  * Validate comment parameter before perform other comments actions
 963  *
 964  * @package  core_blog
 965  * @category comment
 966  *
 967  * @param stdClass $comment {
 968  *              context  => context the context object
 969  *              courseid => int course id
 970  *              cm       => stdClass course module object
 971  *              commentarea => string comment area
 972  *              itemid      => int itemid
 973  * }
 974  * @return boolean
 975  */
 976 function blog_comment_validate($comment_param) {
 977     global $CFG, $DB, $USER;
 978
 979     // Check if blogs are enabled user can comment.
 980     if (empty($CFG->enableblogs) || empty($CFG->blogusecomments)) {
 981         throw new comment_exception('nopermissiontocomment');
 982     }
 983
 984     // Validate comment area.
 985     if ($comment_param->commentarea != 'format_blog') {
 986         throw new comment_exception('invalidcommentarea');
 987     }
 988
 989     $blogentry = $DB->get_record('post', array('id' => $comment_param->itemid), '*', MUST_EXIST);
 990
 991     // Validation for comment deletion.
 992     if (!empty($comment_param->commentid)) {
 993         if ($record = $DB->get_record('comments', array('id'=>$comment_param->commentid))) {
 994             if ($record->commentarea != 'format_blog') {
 995                 throw new comment_exception('invalidcommentarea');
 996             }
 997             if ($record->contextid != $comment_param->context->id) {
 998                 throw new comment_exception('invalidcontext');
 999             }
1000             if ($record->itemid != $comment_param->itemid) {
1001                 throw new comment_exception('invalidcommentitemid');
1002             }
1003         } else {
1004             throw new comment_exception('invalidcommentid');
1005         }
1006     }
1007
1008     // Validate if user has blog view permission.
1009     $sitecontext = context_system::instance();
1010     return has_capability('moodle/blog:view', $sitecontext) &&
1011             blog_user_can_view_user_entry($blogentry->userid, $blogentry);
1012 }
1013
1014 /**
1015  * Return a list of page types
1016  * @param string $pagetype current page type
1017  * @param stdClass $parentcontext Block's parent context
1018  * @param stdClass $currentcontext Current context of block
1019  */
1020 function blog_page_type_list($pagetype, $parentcontext, $currentcontext) {
1021     return array(
1022         '*'=>get_string('page-x', 'pagetype'),
1023         'blog-*'=>get_string('page-blog-x', 'blog'),
1024         'blog-index'=>get_string('page-blog-index', 'blog'),
1025         'blog-edit'=>get_string('page-blog-edit', 'blog')
1026     );
1027 }