blog/lib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * Core global functions for Blog.
  20  *
  21  * @package    moodlecore
  22  * @subpackage blog
  23  * @copyright  2009 Nicolas Connault
  24  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27 defined('MOODLE_INTERNAL') || die();
  28
  29 /**
  30  * Library of functions and constants for blog
  31  */
  32 require_once($CFG->dirroot .'/blog/rsslib.php');
  33 require_once($CFG->dirroot.'/tag/lib.php');
  34
  35 /**
  36  * User can edit a blog entry if this is their own blog entry and they have
  37  * the capability moodle/blog:create, or if they have the capability
  38  * moodle/blog:manageentries.
  39  *
  40  * This also applies to deleting of entries.
  41  */
  42 function blog_user_can_edit_entry($blogentry) {
  43     global $USER;
  44
  45     $sitecontext = get_context_instance(CONTEXT_SYSTEM);
  46
  47     if (has_capability('moodle/blog:manageentries', $sitecontext)) {
  48         return true; // can edit any blog entry
  49     }
  50
  51     if ($blogentry->userid == $USER->id && has_capability('moodle/blog:create', $sitecontext)) {
  52         return true; // can edit own when having blog:create capability
  53     }
  54
  55     return false;
  56 }
  57
  58
  59 /**
  60  * Checks to see if a user can view the blogs of another user.
  61  * Only blog level is checked here, the capabilities are enforced
  62  * in blog/index.php
  63  */
  64 function blog_user_can_view_user_entry($targetuserid, $blogentry=null) {
  65     global $CFG, $USER, $DB;
  66
  67     if (empty($CFG->bloglevel)) {
  68         return false; // blog system disabled
  69     }
  70
  71     if (isloggedin() && $USER->id == $targetuserid) {
  72         return true; // can view own entries in any case
  73     }
  74
  75     $sitecontext = get_context_instance(CONTEXT_SYSTEM);
  76     if (has_capability('moodle/blog:manageentries', $sitecontext)) {
  77         return true; // can manage all entries
  78     }
  79
  80     // coming for 1 entry, make sure it's not a draft
  81     if ($blogentry && $blogentry->publishstate == 'draft' && !has_capability('moodle/blog:viewdrafts', $sitecontext)) {
  82         return false;  // can not view draft of others
  83     }
  84
  85     // coming for 0 entry, make sure user is logged in, if not a public blog
  86     if ($blogentry && $blogentry->publishstate != 'public' && !isloggedin()) {
  87         return false;
  88     }
  89
  90     switch ($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             $personalcontext = get_context_instance(CONTEXT_USER, $targetuserid);
 105             return has_capability('moodle/user:readuserblogs', $personalcontext);
 106         break;
 107
 108     }
 109 }
 110
 111 /**
 112  * remove all associations for the blog entries of a particular user
 113  * @param int userid - id of user whose blog associations will be deleted
 114  */
 115 function blog_remove_associations_for_user($userid) {
 116     global $DB;
 117     throw new coding_exception('function blog_remove_associations_for_user() is not finished');
 118     /*
 119     $blogentries = blog_fetch_entries(array('user' => $userid), 'lasmodified DESC');
 120     foreach ($blogentries as $entry) {
 121         if (blog_user_can_edit_entry($entry)) {
 122             blog_remove_associations_for_entry($entry->id);
 123         }
 124     }
 125      */
 126 }
 127
 128 /**
 129  * remove all associations for the blog entries of a particular course
 130  * @param int courseid - id of user whose blog associations will be deleted
 131  */
 132 function blog_remove_associations_for_course($courseid) {
 133     global $DB;
 134     $context = get_context_instance(CONTEXT_COURSE, $courseid);
 135     $DB->delete_records('blog_association', array('contextid' => $context->id));
 136 }
 137
 138 /**
 139  * Given a record in the {blog_external} table, checks the blog's URL
 140  * for new entries not yet copied into Moodle.
 141  * Also attempts to identify and remove deleted blog entries
 142  *
 143  * @param object $externalblog
 144  * @return boolean False if the Feed is invalid
 145  */
 146 function blog_sync_external_entries($externalblog) {
 147     global $CFG, $DB;
 148     require_once($CFG->libdir . '/simplepie/moodle_simplepie.php');
 149
 150     $rssfile = new moodle_simplepie_file($externalblog->url);
 151     $filetest = new SimplePie_Locator($rssfile);
 152
 153     if (!$filetest->is_feed($rssfile)) {
 154         $externalblog->failedlastsync = 1;
 155         $DB->update_record('blog_external', $externalblog);
 156         return false;
 157     } else if (!empty($externalblog->failedlastsync)) {
 158         $externalblog->failedlastsync = 0;
 159         $DB->update_record('blog_external', $externalblog);
 160     }
 161
 162     $rss = new moodle_simplepie($externalblog->url);
 163
 164     if (empty($rss->data)) {
 165         return null;
 166     }
 167     //used to identify blog posts that have been deleted from the source feed
 168     $oldesttimestamp = null;
 169     $uniquehashes = array();
 170
 171     foreach ($rss->get_items() as $entry) {
 172         // If filtertags are defined, use them to filter the entries by RSS category
 173         if (!empty($externalblog->filtertags)) {
 174             $containsfiltertag = false;
 175             $categories = $entry->get_categories();
 176             $filtertags = explode(',', $externalblog->filtertags);
 177             $filtertags = array_map('trim', $filtertags);
 178             $filtertags = array_map('strtolower', $filtertags);
 179
 180             foreach ($categories as $category) {
 181                 if (in_array(trim(strtolower($category->term)), $filtertags)) {
 182                     $containsfiltertag = true;
 183                 }
 184             }
 185
 186             if (!$containsfiltertag) {
 187                 continue;
 188             }
 189         }
 190
 191         $uniquehashes[] = $entry->get_permalink();
 192
 193         $newentry = new stdClass();
 194         $newentry->userid = $externalblog->userid;
 195         $newentry->module = 'blog_external';
 196         $newentry->content = $externalblog->id;
 197         $newentry->uniquehash = $entry->get_permalink();
 198         $newentry->publishstate = 'site';
 199         $newentry->format = FORMAT_HTML;
 200         // Clean subject of html, just in case
 201         $newentry->subject = clean_param($entry->get_title(), PARAM_TEXT);
 202         // Observe 128 max chars in DB
 203         // TODO: +1 to raise this to 255
 204         if (textlib::strlen($newentry->subject) > 128) {
 205             $newentry->subject = textlib::substr($newentry->subject, 0, 125) . '...';
 206         }
 207         $newentry->summary = $entry->get_description();
 208
 209         //used to decide whether to insert or update
 210         //uses enty permalink plus creation date if available
 211         $existingpostconditions = array('uniquehash' => $entry->get_permalink());
 212
 213         //our DB doesnt allow null creation or modified timestamps so check the external blog supplied one
 214         $entrydate = $entry->get_date('U');
 215         if (!empty($entrydate)) {
 216             $existingpostconditions['created'] = $entrydate;
 217         }
 218
 219         //the post ID or false if post not found in DB
 220         $postid = $DB->get_field('post', 'id', $existingpostconditions);
 221
 222         $timestamp = null;
 223         if (empty($entrydate)) {
 224             $timestamp = time();
 225         } else {
 226             $timestamp = $entrydate;
 227         }
 228
 229         //only set created if its a new post so we retain the original creation timestamp if the post is edited
 230         if ($postid === false) {
 231             $newentry->created = $timestamp;
 232         }
 233         $newentry->lastmodified = $timestamp;
 234
 235         if (empty($oldesttimestamp) || $timestamp < $oldesttimestamp) {
 236             //found an older post
 237             $oldesttimestamp = $timestamp;
 238         }
 239
 240         if (textlib::strlen($newentry->uniquehash) > 255) {
 241             // The URL for this item is too long for the field. Rather than add
 242             // the entry without the link we will skip straight over it.
 243             // RSS spec says recommended length 500, we use 255.
 244             debugging('External blog entry skipped because of oversized URL', DEBUG_DEVELOPER);
 245             continue;
 246         }
 247
 248         if ($postid === false) {
 249             $id = $DB->insert_record('post', $newentry);
 250
 251             // Set tags
 252             if ($tags = tag_get_tags_array('blog_external', $externalblog->id)) {
 253                 tag_set('post', $id, $tags);
 254             }
 255         } else {
 256             $newentry->id = $postid;
 257             $DB->update_record('post', $newentry);
 258         }
 259     }
 260
 261     // Look at the posts we have in the database to check if any of them have been deleted from the feed.
 262     // Only checking posts within the time frame returned by the rss feed. Older items may have been deleted or
 263     // may just not be returned anymore. We can't tell the difference so we leave older posts alone.
 264     $sql = "SELECT id, uniquehash
 265               FROM {post}
 266              WHERE module = 'blog_external'
 267                    AND " . $DB->sql_compare_text('content') . " = " . $DB->sql_compare_text(':blogid') . "
 268                    AND created > :ts";
 269     $dbposts = $DB->get_records_sql($sql, array('blogid' => $externalblog->id, 'ts' => $oldesttimestamp));
 270
 271     $todelete = array();
 272     foreach($dbposts as $dbpost) {
 273         if ( !in_array($dbpost->uniquehash, $uniquehashes) ) {
 274             $todelete[] = $dbpost->id;
 275         }
 276     }
 277     $DB->delete_records_list('post', 'id', $todelete);
 278
 279     $DB->update_record('blog_external', array('id' => $externalblog->id, 'timefetched' => time()));
 280 }
 281
 282 /**
 283  * Given an external blog object, deletes all related blog entries from the post table.
 284  * NOTE: The external blog's id is saved as post.content, a field that is not oterhwise used by blog entries.
 285  * @param object $externablog
 286  */
 287 function blog_delete_external_entries($externalblog) {
 288     global $DB;
 289     require_capability('moodle/blog:manageexternal', get_context_instance(CONTEXT_SYSTEM));
 290     $DB->delete_records_select('post',
 291                                "module='blog_external' AND " . $DB->sql_compare_text('content') . " = ?",
 292                                array($externalblog->id));
 293 }
 294
 295 /**
 296  * Returns a URL based on the context of the current page.
 297  * This URL points to blog/index.php and includes filter parameters appropriate for the current page.
 298  *
 299  * @param stdclass $context
 300  * @return string
 301  */
 302 function blog_get_context_url($context=null) {
 303     global $CFG;
 304
 305     $viewblogentriesurl = new moodle_url('/blog/index.php');
 306
 307     if (empty($context)) {
 308         global $PAGE;
 309         $context = $PAGE->context;
 310     }
 311
 312     // Change contextlevel to SYSTEM if viewing the site course
 313     if ($context->contextlevel == CONTEXT_COURSE && $context->instanceid == SITEID) {
 314         $context = context_system::instance();
 315     }
 316
 317     $filterparam = '';
 318     $strlevel = '';
 319
 320     switch ($context->contextlevel) {
 321         case CONTEXT_SYSTEM:
 322         case CONTEXT_BLOCK:
 323         case CONTEXT_COURSECAT:
 324             break;
 325         case CONTEXT_COURSE:
 326             $filterparam = 'courseid';
 327             $strlevel = get_string('course');
 328             break;
 329         case CONTEXT_MODULE:
 330             $filterparam = 'modid';
 331             $strlevel = print_context_name($context);
 332             break;
 333         case CONTEXT_USER:
 334             $filterparam = 'userid';
 335             $strlevel = get_string('user');
 336             break;
 337     }
 338
 339     if (!empty($filterparam)) {
 340         $viewblogentriesurl->param($filterparam, $context->instanceid);
 341     }
 342
 343     return $viewblogentriesurl;
 344 }
 345
 346 /**
 347  * This function checks that blogs are enabled, and that the user can see blogs at all
 348  * @return bool
 349  */
 350 function blog_is_enabled_for_user() {
 351     global $CFG;
 352     //return (!empty($CFG->bloglevel) && $CFG->bloglevel <= BLOG_GLOBAL_LEVEL && isloggedin() && !isguestuser());
 353     return (!empty($CFG->bloglevel) && (isloggedin() || ($CFG->bloglevel == BLOG_GLOBAL_LEVEL)));
 354 }
 355
 356 /**
 357  * This function gets all of the options available for the current user in respect
 358  * to blogs.
 359  *
 360  * It loads the following if applicable:
 361  * -  Module options {@see blog_get_options_for_module}
 362  * -  Course options {@see blog_get_options_for_course}
 363  * -  User specific options {@see blog_get_options_for_user}
 364  * -  General options (BLOG_LEVEL_GLOBAL)
 365  *
 366  * @param moodle_page $page The page to load for (normally $PAGE)
 367  * @param stdClass $userid Load for a specific user
 368  * @return array An array of options organised by type.
 369  */
 370 function blog_get_all_options(moodle_page $page, stdClass $userid = null) {
 371     global $CFG, $DB, $USER;
 372
 373     $options = array();
 374
 375     // If blogs are enabled and the user is logged in and not a guest
 376     if (blog_is_enabled_for_user()) {
 377         // If the context is the user then assume we want to load for the users context
 378         if (is_null($userid) && $page->context->contextlevel == CONTEXT_USER) {
 379             $userid = $page->context->instanceid;
 380         }
 381         // Check the userid var
 382         if (!is_null($userid) && $userid!==$USER->id) {
 383             // Load the user from the userid... it MUST EXIST throw a wobbly if it doesn't!
 384             $user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
 385         } else {
 386             $user = null;
 387         }
 388
 389         if ($CFG->useblogassociations && $page->cm !== null) {
 390             // Load for the module associated with the page
 391             $options[CONTEXT_MODULE] = blog_get_options_for_module($page->cm, $user);
 392         } else if ($CFG->useblogassociations && $page->course->id != SITEID) {
 393             // Load the options for the course associated with the page
 394             $options[CONTEXT_COURSE] = blog_get_options_for_course($page->course, $user);
 395         }
 396
 397         // Get the options for the user
 398         if ($user !== null and !isguestuser($user)) {
 399             // Load for the requested user
 400             $options[CONTEXT_USER+1] = blog_get_options_for_user($user);
 401         }
 402         // Load for the current user
 403         if (isloggedin() and !isguestuser()) {
 404             $options[CONTEXT_USER] = blog_get_options_for_user();
 405         }
 406     }
 407
 408     // If blog level is global then display a link to view all site entries
 409     if (!empty($CFG->bloglevel) && $CFG->bloglevel >= BLOG_GLOBAL_LEVEL && has_capability('moodle/blog:view', get_context_instance(CONTEXT_SYSTEM))) {
 410         $options[CONTEXT_SYSTEM] = array('viewsite' => array(
 411             'string' => get_string('viewsiteentries', 'blog'),
 412             'link' => new moodle_url('/blog/index.php')
 413         ));
 414     }
 415
 416     // Return the options
 417     return $options;
 418 }
 419
 420 /**
 421  * Get all of the blog options that relate to the passed user.
 422  *
 423  * If no user is passed the current user is assumed.
 424  *
 425  * @staticvar array $useroptions Cache so we don't have to regenerate multiple times
 426  * @param stdClass $user
 427  * @return array The array of options for the requested user
 428  */
 429 function blog_get_options_for_user(stdClass $user=null) {
 430     global $CFG, $USER;
 431     // Cache
 432     static $useroptions = array();
 433
 434     $options = array();
 435     // Blogs must be enabled and the user must be logged in
 436     if (!blog_is_enabled_for_user()) {
 437         return $options;
 438     }
 439
 440     // Sort out the user var
 441     if ($user === null || $user->id == $USER->id) {
 442         $user = $USER;
 443         $iscurrentuser = true;
 444     } else {
 445         $iscurrentuser = false;
 446     }
 447
 448     // If we've already generated serve from the cache
 449     if (array_key_exists($user->id, $useroptions)) {
 450         return $useroptions[$user->id];
 451     }
 452
 453     $sitecontext = get_context_instance(CONTEXT_SYSTEM);
 454     $canview = has_capability('moodle/blog:view', $sitecontext);
 455
 456     if (!$iscurrentuser && $canview && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 457         // Not the current user, but we can view and its blogs are enabled for SITE or GLOBAL
 458         $options['userentries'] = array(
 459             'string' => get_string('viewuserentries', 'blog', fullname($user)),
 460             'link' => new moodle_url('/blog/index.php', array('userid'=>$user->id))
 461         );
 462     } else {
 463         // It's the current user
 464         if ($canview) {
 465             // We can view our own blogs .... BIG surprise
 466             $options['view'] = array(
 467                 'string' => get_string('viewallmyentries', 'blog'),
 468                 'link' => new moodle_url('/blog/index.php', array('userid'=>$USER->id))
 469             );
 470         }
 471         if (has_capability('moodle/blog:create', $sitecontext)) {
 472             // We can add to our own blog
 473             $options['add'] = array(
 474                 'string' => get_string('addnewentry', 'blog'),
 475                 'link' => new moodle_url('/blog/edit.php', array('action'=>'add'))
 476             );
 477         }
 478     }
 479     if ($canview && $CFG->enablerssfeeds) {
 480         $options['rss'] = array(
 481             'string' => get_string('rssfeed', 'blog'),
 482             'link' => new moodle_url(rss_get_url($sitecontext->id, $USER->id, 'blog', 'user/'.$user->id))
 483        );
 484     }
 485
 486     // Cache the options
 487     $useroptions[$user->id] = $options;
 488     // Return the options
 489     return $options;
 490 }
 491
 492 /**
 493  * Get the blog options that relate to the given course for the given user.
 494  *
 495  * @staticvar array $courseoptions A cache so we can save regenerating multiple times
 496  * @param stdClass $course The course to load options for
 497  * @param stdClass $user The user to load options for null == current user
 498  * @return array The array of options
 499  */
 500 function blog_get_options_for_course(stdClass $course, stdClass $user=null) {
 501     global $CFG, $USER;
 502     // Cache
 503     static $courseoptions = array();
 504
 505     $options = array();
 506
 507     // User must be logged in and blogs must be enabled
 508     if (!blog_is_enabled_for_user()) {
 509         return $options;
 510     }
 511
 512     // Check that the user can associate with the course
 513     $sitecontext =      get_context_instance(CONTEXT_SYSTEM);
 514     if (!has_capability('moodle/blog:associatecourse', $sitecontext)) {
 515         return $options;
 516     }
 517     // Generate the cache key
 518     $key = $course->id.':';
 519     if (!empty($user)) {
 520         $key .= $user->id;
 521     } else {
 522         $key .= $USER->id;
 523     }
 524     // Serve from the cache if we've already generated for this course
 525     if (array_key_exists($key, $courseoptions)) {
 526         return $courseoptions[$key];
 527     }
 528
 529     $coursecontext = get_context_instance(CONTEXT_COURSE, $course->id);
 530     $canparticipate = (is_enrolled($coursecontext) or is_viewing($coursecontext));
 531
 532     if (has_capability('moodle/blog:view', $coursecontext)) {
 533         // We can view!
 534         if ($CFG->bloglevel >= BLOG_SITE_LEVEL) {
 535             // View entries about this course
 536             $options['courseview'] = array(
 537                 'string' => get_string('viewcourseblogs', 'blog'),
 538                 'link' => new moodle_url('/blog/index.php', array('courseid'=>$course->id))
 539             );
 540         }
 541         // View MY entries about this course
 542         $options['courseviewmine'] = array(
 543             'string' => get_string('viewmyentriesaboutcourse', 'blog'),
 544             'link' => new moodle_url('/blog/index.php', array('courseid'=>$course->id, 'userid'=>$USER->id))
 545         );
 546         if (!empty($user) && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 547             // View the provided users entries about this course
 548             $options['courseviewuser'] = array(
 549                 'string' => get_string('viewentriesbyuseraboutcourse', 'blog', fullname($user)),
 550                 'link' => new moodle_url('/blog/index.php', array('courseid'=>$course->id, 'userid'=>$user->id))
 551             );
 552         }
 553     }
 554
 555     if (has_capability('moodle/blog:create', $sitecontext) and $canparticipate) {
 556         // We can blog about this course
 557         $options['courseadd'] = array(
 558             'string' => get_string('blogaboutthiscourse', 'blog'),
 559             'link' => new moodle_url('/blog/edit.php', array('action'=>'add', 'courseid'=>$course->id))
 560         );
 561     }
 562
 563
 564     // Cache the options for this course
 565     $courseoptions[$key] = $options;
 566     // Return the options
 567     return $options;
 568 }
 569
 570 /**
 571  * Get the blog options relating to the given module for the given user
 572  *
 573  * @staticvar array $moduleoptions Cache
 574  * @param stdClass|cm_info $module The module to get options for
 575  * @param stdClass $user The user to get options for null == currentuser
 576  * @return array
 577  */
 578 function blog_get_options_for_module($module, $user=null) {
 579     global $CFG, $USER;
 580     // Cache
 581     static $moduleoptions = array();
 582
 583     $options = array();
 584     // User must be logged in, blogs must be enabled
 585     if (!blog_is_enabled_for_user()) {
 586         return $options;
 587     }
 588
 589     // Check the user can associate with the module
 590     $sitecontext =      get_context_instance(CONTEXT_SYSTEM);
 591     if (!has_capability('moodle/blog:associatemodule', $sitecontext)) {
 592         return $options;
 593     }
 594
 595     // Generate the cache key
 596     $key = $module->id.':';
 597     if (!empty($user)) {
 598         $key .= $user->id;
 599     } else {
 600         $key .= $USER->id;
 601     }
 602     if (array_key_exists($key, $moduleoptions)) {
 603         // Serve from the cache so we don't have to regenerate
 604         return $moduleoptions[$module->id];
 605     }
 606
 607     $modcontext = get_context_instance(CONTEXT_MODULE, $module->id);
 608     $canparticipate = (is_enrolled($modcontext) or is_viewing($modcontext));
 609
 610     if (has_capability('moodle/blog:view', $modcontext)) {
 611         // We can view!
 612         if ($CFG->bloglevel >= BLOG_SITE_LEVEL) {
 613             // View all entries about this module
 614             $a = new stdClass;
 615             $a->type = $module->modname;
 616             $options['moduleview'] = array(
 617                 'string' => get_string('viewallmodentries', 'blog', $a),
 618                 'link' => new moodle_url('/blog/index.php', array('modid'=>$module->id))
 619             );
 620         }
 621         // View MY entries about this module
 622         $options['moduleviewmine'] = array(
 623             'string' => get_string('viewmyentriesaboutmodule', 'blog', $module->modname),
 624             'link' => new moodle_url('/blog/index.php', array('modid'=>$module->id, 'userid'=>$USER->id))
 625         );
 626         if (!empty($user) && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 627             // View the given users entries about this module
 628             $a = new stdClass;
 629             $a->mod = $module->modname;
 630             $a->user = fullname($user);
 631             $options['moduleviewuser'] = array(
 632                 'string' => get_string('blogentriesbyuseraboutmodule', 'blog', $a),
 633                 'link' => new moodle_url('/blog/index.php', array('modid'=>$module->id, 'userid'=>$user->id))
 634             );
 635         }
 636     }
 637
 638     if (has_capability('moodle/blog:create', $sitecontext) and $canparticipate) {
 639         // The user can blog about this module
 640         $options['moduleadd'] = array(
 641             'string' => get_string('blogaboutthismodule', 'blog', $module->modname),
 642             'link' => new moodle_url('/blog/edit.php', array('action'=>'add', 'modid'=>$module->id))
 643         );
 644     }
 645     // Cache the options
 646     $moduleoptions[$key] = $options;
 647     // Return the options
 648     return $options;
 649 }
 650
 651 /**
 652  * This function encapsulates all the logic behind the complex
 653  * navigation, titles and headings of the blog listing page, depending
 654  * on URL params. It looks at URL params and at the current context level.
 655  * It builds and returns an array containing:
 656  *
 657  * 1. heading: The heading displayed above the blog entries
 658  * 2. stradd:  The text to be used as the "Add entry" link
 659  * 3. strview: The text to be used as the "View entries" link
 660  * 4. url:     The moodle_url object used as the base for add and view links
 661  * 5. filters: An array of parameters used to filter blog listings. Used by index.php and the Recent blogs block
 662  *
 663  * All other variables are set directly in $PAGE
 664  *
 665  * It uses the current URL to build these variables.
 666  * A number of mutually exclusive use cases are used to structure this function.
 667  *
 668  * @return array
 669  */
 670 function blog_get_headers($courseid=null, $groupid=null, $userid=null, $tagid=null) {
 671     global $CFG, $PAGE, $DB, $USER;
 672
 673     $id       = optional_param('id', null, PARAM_INT);
 674     $tag      = optional_param('tag', null, PARAM_NOTAGS);
 675     $tagid    = optional_param('tagid', $tagid, PARAM_INT);
 676     $userid   = optional_param('userid', $userid, PARAM_INT);
 677     $modid    = optional_param('modid', null, PARAM_INT);
 678     $entryid  = optional_param('entryid', null, PARAM_INT);
 679     $groupid  = optional_param('groupid', $groupid, PARAM_INT);
 680     $courseid = optional_param('courseid', $courseid, PARAM_INT);
 681     $search   = optional_param('search', null, PARAM_RAW);
 682     $action   = optional_param('action', null, PARAM_ALPHA);
 683     $confirm  = optional_param('confirm', false, PARAM_BOOL);
 684
 685     // Ignore userid when action == add
 686     if ($action == 'add' && $userid) {
 687         unset($userid);
 688         $PAGE->url->remove_params(array('userid'));
 689     } else if ($action == 'add' && $entryid) {
 690         unset($entryid);
 691         $PAGE->url->remove_params(array('entryid'));
 692     }
 693
 694     $headers = array('title' => '', 'heading' => '', 'cm' => null, 'filters' => array());
 695
 696     $blogurl = new moodle_url('/blog/index.php');
 697
 698     // If the title is not yet set, it's likely that the context isn't set either, so skip this part
 699     $pagetitle = $PAGE->title;
 700     if (!empty($pagetitle)) {
 701         $contexturl = blog_get_context_url();
 702
 703         // Look at the context URL, it may have additional params that are not in the current URL
 704         if (!$blogurl->compare($contexturl)) {
 705             $blogurl = $contexturl;
 706             if (empty($courseid)) {
 707                 $courseid = $blogurl->param('courseid');
 708             }
 709             if (empty($modid)) {
 710                 $modid = $blogurl->param('modid');
 711             }
 712         }
 713     }
 714
 715     $headers['stradd'] = get_string('addnewentry', 'blog');
 716     $headers['strview'] = null;
 717
 718     $site = $DB->get_record('course', array('id' => SITEID));
 719     $sitecontext = get_context_instance(CONTEXT_SYSTEM);
 720     // Common Lang strings
 721     $strparticipants = get_string("participants");
 722     $strblogentries  = get_string("blogentries", 'blog');
 723
 724     // Prepare record objects as needed
 725     if (!empty($courseid)) {
 726         $headers['filters']['course'] = $courseid;
 727         $course = $DB->get_record('course', array('id' => $courseid));
 728     }
 729
 730     if (!empty($userid)) {
 731         $headers['filters']['user'] = $userid;
 732         $user = $DB->get_record('user', array('id' => $userid));
 733     }
 734
 735     if (!empty($groupid)) { // groupid always overrides courseid
 736         $headers['filters']['group'] = $groupid;
 737         $group = $DB->get_record('groups', array('id' => $groupid));
 738         $course = $DB->get_record('course', array('id' => $group->courseid));
 739     }
 740
 741     $PAGE->set_pagelayout('standard');
 742
 743     if (!empty($modid) && $CFG->useblogassociations && has_capability('moodle/blog:associatemodule', $sitecontext)) { // modid always overrides courseid, so the $course object may be reset here
 744         $headers['filters']['module'] = $modid;
 745         // A groupid param may conflict with this coursemod's courseid. Ignore groupid in that case
 746         $courseid = $DB->get_field('course_modules', 'course', array('id'=>$modid));
 747         $course = $DB->get_record('course', array('id' => $courseid));
 748         $cm = $DB->get_record('course_modules', array('id' => $modid));
 749         $cm->modname = $DB->get_field('modules', 'name', array('id' => $cm->module));
 750         $cm->name = $DB->get_field($cm->modname, 'name', array('id' => $cm->instance));
 751         $a = new stdClass();
 752         $a->type = get_string('modulename', $cm->modname);
 753         $PAGE->set_cm($cm, $course);
 754         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 755         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 756     }
 757
 758     // Case 1: No entry, mod, course or user params: all site entries to be shown (filtered by search and tag/tagid)
 759     // Note: if action is set to 'add' or 'edit', we do this at the end
 760     if (empty($entryid) && empty($modid) && empty($courseid) && empty($userid) && !in_array($action, array('edit', 'add'))) {
 761         $shortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 762         $PAGE->navbar->add($strblogentries, $blogurl);
 763         $PAGE->set_title("$shortname: " . get_string('blog', 'blog'));
 764         $PAGE->set_heading("$shortname: " . get_string('blog', 'blog'));
 765         $headers['heading'] = get_string('siteblog', 'blog', $shortname);
 766         // $headers['strview'] = get_string('viewsiteentries', 'blog');
 767     }
 768
 769     // Case 2: only entryid is requested, ignore all other filters. courseid is used to give more contextual information
 770     if (!empty($entryid)) {
 771         $headers['filters']['entry'] = $entryid;
 772         $sql = 'SELECT u.* FROM {user} u, {post} p WHERE p.id = ? AND p.userid = u.id';
 773         $user = $DB->get_record_sql($sql, array($entryid));
 774         $entry = $DB->get_record('post', array('id' => $entryid));
 775
 776         $blogurl->param('userid', $user->id);
 777
 778         if (!empty($course)) {
 779             $mycourseid = $course->id;
 780             $blogurl->param('courseid', $mycourseid);
 781         } else {
 782             $mycourseid = $site->id;
 783         }
 784         $shortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 785
 786         $PAGE->navbar->add($strblogentries, $blogurl);
 787
 788         $blogurl->remove_params('userid');
 789         $PAGE->navbar->add($entry->subject, $blogurl);
 790         $PAGE->set_title("$shortname: " . fullname($user) . ": $entry->subject");
 791         $PAGE->set_heading("$shortname: " . fullname($user) . ": $entry->subject");
 792         $headers['heading'] = get_string('blogentrybyuser', 'blog', fullname($user));
 793
 794         // We ignore tag and search params
 795         if (empty($action) || !$CFG->useblogassociations) {
 796             $headers['url'] = $blogurl;
 797             return $headers;
 798         }
 799     }
 800
 801     // Case 3: A user's blog entries
 802     if (!empty($userid) && empty($entryid) && ((empty($courseid) && empty($modid)) || !$CFG->useblogassociations)) {
 803         $shortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 804         $blogurl->param('userid', $userid);
 805         $PAGE->set_title("$shortname: " . fullname($user) . ": " . get_string('blog', 'blog'));
 806         $PAGE->set_heading("$shortname: " . fullname($user) . ": " . get_string('blog', 'blog'));
 807         $headers['heading'] = get_string('userblog', 'blog', fullname($user));
 808         $headers['strview'] = get_string('viewuserentries', 'blog', fullname($user));
 809
 810     } else
 811
 812     // Case 4: No blog associations, no userid
 813     if (!$CFG->useblogassociations && empty($userid) && !in_array($action, array('edit', 'add'))) {
 814         $shortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 815         $PAGE->set_title("$shortname: " . get_string('blog', 'blog'));
 816         $PAGE->set_heading("$shortname: " . get_string('blog', 'blog'));
 817         $headers['heading'] = get_string('siteblog', 'blog', $shortname);
 818     } else
 819
 820     // Case 5: Blog entries associated with an activity by a specific user (courseid ignored)
 821     if (!empty($userid) && !empty($modid) && empty($entryid)) {
 822         $shortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 823         $blogurl->param('userid', $userid);
 824         $blogurl->param('modid', $modid);
 825
 826         // Course module navigation is handled by build_navigation as the second param
 827         $headers['cm'] = $cm;
 828         $PAGE->navbar->add(fullname($user), "$CFG->wwwroot/user/view.php?id=$user->id");
 829         $PAGE->navbar->add($strblogentries, $blogurl);
 830
 831         $PAGE->set_title("$shortname: $cm->name: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 832         $PAGE->set_heading("$shortname: $cm->name: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 833
 834         $a = new stdClass();
 835         $a->user = fullname($user);
 836         $a->mod = $cm->name;
 837         $a->type = get_string('modulename', $cm->modname);
 838         $headers['heading'] = get_string('blogentriesbyuseraboutmodule', 'blog', $a);
 839         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 840         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 841     } else
 842
 843     // Case 6: Blog entries associated with a course by a specific user
 844     if (!empty($userid) && !empty($courseid) && empty($modid) && empty($entryid)) {
 845         $siteshortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 846         $courseshortname = format_string($course->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));
 847         $blogurl->param('userid', $userid);
 848         $blogurl->param('courseid', $courseid);
 849
 850         $PAGE->navbar->add($strblogentries, $blogurl);
 851
 852         $PAGE->set_title("$siteshortname: $courseshortname: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 853         $PAGE->set_heading("$siteshortname: $courseshortname: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 854
 855         $a = new stdClass();
 856         $a->user = fullname($user);
 857         $a->course = format_string($course->fullname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));
 858         $a->type = get_string('course');
 859         $headers['heading'] = get_string('blogentriesbyuseraboutcourse', 'blog', $a);
 860         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 861         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 862
 863         // Remove the userid from the URL to inform the blog_menu block correctly
 864         $blogurl->remove_params(array('userid'));
 865     } else
 866
 867     // Case 7: Blog entries by members of a group, associated with that group's course
 868     if (!empty($groupid) && empty($modid) && empty($entryid)) {
 869         $siteshortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 870         $courseshortname = format_string($course->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));
 871         $blogurl->param('courseid', $course->id);
 872
 873         $PAGE->navbar->add($strblogentries, $blogurl);
 874         $blogurl->remove_params(array('courseid'));
 875         $blogurl->param('groupid', $groupid);
 876         $PAGE->navbar->add($group->name, $blogurl);
 877
 878         $PAGE->set_title("$siteshortname: $courseshortname: " . get_string('blogentries', 'blog') . ": $group->name");
 879         $PAGE->set_heading("$siteshortname: $courseshortname: " . get_string('blogentries', 'blog') . ": $group->name");
 880
 881         $a = new stdClass();
 882         $a->group = $group->name;
 883         $a->course = format_string($course->fullname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));
 884         $a->type = get_string('course');
 885         $headers['heading'] = get_string('blogentriesbygroupaboutcourse', 'blog', $a);
 886         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 887         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 888     } else
 889
 890     // Case 8: Blog entries by members of a group, associated with an activity in that course
 891     if (!empty($groupid) && !empty($modid) && empty($entryid)) {
 892         $siteshortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 893         $courseshortname = format_string($course->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));
 894         $headers['cm'] = $cm;
 895         $blogurl->param('modid', $modid);
 896         $PAGE->navbar->add($strblogentries, $blogurl);
 897
 898         $blogurl->param('groupid', $groupid);
 899         $PAGE->navbar->add($group->name, $blogurl);
 900
 901         $PAGE->set_title("$siteshortname: $courseshortname: $cm->name: " . get_string('blogentries', 'blog') . ": $group->name");
 902         $PAGE->set_heading("$siteshortname: $courseshortname: $cm->name: " . get_string('blogentries', 'blog') . ": $group->name");
 903
 904         $a = new stdClass();
 905         $a->group = $group->name;
 906         $a->mod = $cm->name;
 907         $a->type = get_string('modulename', $cm->modname);
 908         $headers['heading'] = get_string('blogentriesbygroupaboutmodule', 'blog', $a);
 909         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 910         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 911
 912     } else
 913
 914     // Case 9: All blog entries associated with an activity
 915     if (!empty($modid) && empty($userid) && empty($groupid) && empty($entryid)) {
 916         $siteshortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 917         $courseshortname = format_string($course->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));
 918         $PAGE->set_cm($cm, $course);
 919         $blogurl->param('modid', $modid);
 920         $PAGE->navbar->add($strblogentries, $blogurl);
 921         $PAGE->set_title("$siteshortname: $courseshortname: $cm->name: " . get_string('blogentries', 'blog'));
 922         $PAGE->set_heading("$siteshortname: $courseshortname: $cm->name: " . get_string('blogentries', 'blog'));
 923         $headers['heading'] = get_string('blogentriesabout', 'blog', $cm->name);
 924         $a = new stdClass();
 925         $a->type = get_string('modulename', $cm->modname);
 926         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 927         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 928     } else
 929
 930     // Case 10: All blog entries associated with a course
 931     if (!empty($courseid) && empty($userid) && empty($groupid) && empty($modid) && empty($entryid)) {
 932         $siteshortname = format_string($site->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
 933         $courseshortname = format_string($course->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));
 934         $blogurl->param('courseid', $courseid);
 935         $PAGE->navbar->add($strblogentries, $blogurl);
 936         $PAGE->set_title("$siteshortname: $courseshortname: " . get_string('blogentries', 'blog'));
 937         $PAGE->set_heading("$siteshortname: $courseshortname: " . get_string('blogentries', 'blog'));
 938         $a = new stdClass();
 939         $a->type = get_string('course');
 940         $headers['heading'] = get_string('blogentriesabout', 'blog', format_string($course->fullname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id))));
 941         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 942         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 943         $blogurl->remove_params(array('userid'));
 944     }
 945
 946     if (!in_array($action, array('edit', 'add'))) {
 947         // Append Tag info
 948         if (!empty($tagid)) {
 949             $headers['filters']['tag'] = $tagid;
 950             $blogurl->param('tagid', $tagid);
 951             $tagrec = $DB->get_record('tag', array('id'=>$tagid));
 952             $PAGE->navbar->add($tagrec->name, $blogurl);
 953         } elseif (!empty($tag)) {
 954             $blogurl->param('tag', $tag);
 955             $PAGE->navbar->add(get_string('tagparam', 'blog', $tag), $blogurl);
 956         }
 957
 958         // Append Search info
 959         if (!empty($search)) {
 960             $headers['filters']['search'] = $search;
 961             $blogurl->param('search', $search);
 962             $PAGE->navbar->add(get_string('searchterm', 'blog', $search), $blogurl->out());
 963         }
 964     }
 965
 966     // Append edit mode info
 967     if (!empty($action) && $action == 'add') {
 968
 969     } else if (!empty($action) && $action == 'edit') {
 970         $PAGE->navbar->add(get_string('editentry', 'blog'));
 971     }
 972
 973     if (empty($headers['url'])) {
 974         $headers['url'] = $blogurl;
 975     }
 976     return $headers;
 977 }
 978
 979 /**
 980  * Shortcut function for getting a count of blog entries associated with a course or a module
 981  * @param int $courseid The ID of the course
 982  * @param int $cmid The ID of the course_modules
 983  * @return string The number of associated entries
 984  */
 985 function blog_get_associated_count($courseid, $cmid=null) {
 986     global $DB;
 987     $context = get_context_instance(CONTEXT_COURSE, $courseid);
 988     if ($cmid) {
 989         $context = get_context_instance(CONTEXT_MODULE, $cmid);
 990     }
 991     return $DB->count_records('blog_association', array('contextid' => $context->id));
 992 }
 993
 994 /**
 995  * Running addtional permission check on plugin, for example, plugins
 996  * may have switch to turn on/off comments option, this callback will
 997  * affect UI display, not like pluginname_comment_validate only throw
 998  * exceptions.
 999  * Capability check has been done in comment->check_permissions(), we
1000  * don't need to do it again here.
1001  *
1002  * @package  core_blog
1003  * @category comment
1004  *
1005  * @param stdClass $comment_param {
1006  *              context  => context the context object
1007  *              courseid => int course id
1008  *              cm       => stdClass course module object
1009  *              commentarea => string comment area
1010  *              itemid      => int itemid
1011  * }
1012  * @return array
1013  */
1014 function blog_comment_permissions($comment_param) {
1015     return array('post'=>true, 'view'=>true);
1016 }
1017
1018 /**
1019  * Validate comment parameter before perform other comments actions
1020  *
1021  * @package  core_blog
1022  * @category comment
1023  *
1024  * @param stdClass $comment {
1025  *              context  => context the context object
1026  *              courseid => int course id
1027  *              cm       => stdClass course module object
1028  *              commentarea => string comment area
1029  *              itemid      => int itemid
1030  * }
1031  * @return boolean
1032  */
1033 function blog_comment_validate($comment_param) {
1034     global $DB;
1035     // validate comment itemid
1036     if (!$entry = $DB->get_record('post', array('id'=>$comment_param->itemid))) {
1037         throw new comment_exception('invalidcommentitemid');
1038     }
1039     // validate comment area
1040     if ($comment_param->commentarea != 'format_blog') {
1041         throw new comment_exception('invalidcommentarea');
1042     }
1043     // validation for comment deletion
1044     if (!empty($comment_param->commentid)) {
1045         if ($record = $DB->get_record('comments', array('id'=>$comment_param->commentid))) {
1046             if ($record->commentarea != 'format_blog') {
1047                 throw new comment_exception('invalidcommentarea');
1048             }
1049             if ($record->contextid != $comment_param->context->id) {
1050                 throw new comment_exception('invalidcontext');
1051             }
1052             if ($record->itemid != $comment_param->itemid) {
1053                 throw new comment_exception('invalidcommentitemid');
1054             }
1055         } else {
1056             throw new comment_exception('invalidcommentid');
1057         }
1058     }
1059     return true;
1060 }
1061
1062 /**
1063  * Return a list of page types
1064  * @param string $pagetype current page type
1065  * @param stdClass $parentcontext Block's parent context
1066  * @param stdClass $currentcontext Current context of block
1067  */
1068 function blog_page_type_list($pagetype, $parentcontext, $currentcontext) {
1069     return array(
1070         '*'=>get_string('page-x', 'pagetype'),
1071         'blog-*'=>get_string('page-blog-x', 'blog'),
1072         'blog-index'=>get_string('page-blog-index', 'blog'),
1073         'blog-edit'=>get_string('page-blog-edit', 'blog')
1074     );
1075 }