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($CFG->dirroot .'/blog/rsslib.php');
  32
  33 /**
  34  * User can edit a blog entry if this is their own blog entry and they have
  35  * the capability moodle/blog:create, or if they have the capability
  36  * moodle/blog:manageentries.
  37  *
  38  * This also applies to deleting of entries.
  39  */
  40 function blog_user_can_edit_entry($blogentry) {
  41     global $USER;
  42
  43     $sitecontext = context_system::instance();
  44
  45     if (has_capability('moodle/blog:manageentries', $sitecontext)) {
  46         return true; // Can edit any blog entry.
  47     }
  48
  49     if ($blogentry->userid == $USER->id && has_capability('moodle/blog:create', $sitecontext)) {
  50         return true; // Can edit own when having blog:create capability.
  51     }
  52
  53     return false;
  54 }
  55
  56
  57 /**
  58  * Checks to see if a user can view the blogs of another user.
  59  * Only blog level is checked here, the capabilities are enforced
  60  * in blog/index.php
  61  */
  62 function blog_user_can_view_user_entry($targetuserid, $blogentry=null) {
  63     global $CFG, $USER, $DB;
  64
  65     if (empty($CFG->enableblogs)) {
  66         return false; // Blog system disabled.
  67     }
  68
  69     if (isloggedin() && $USER->id == $targetuserid) {
  70         return true; // Can view own entries in any case.
  71     }
  72
  73     $sitecontext = context_system::instance();
  74     if (has_capability('moodle/blog:manageentries', $sitecontext)) {
  75         return true; // Can manage all entries.
  76     }
  77
  78     // If blog is in draft state, then make sure user have proper capability.
  79     if ($blogentry && $blogentry->publishstate == 'draft' && !has_capability('moodle/blog:viewdrafts', $sitecontext)) {
  80         return false;  // Can not view draft of others.
  81     }
  82
  83     // If blog entry is not public, make sure user is logged in.
  84     if ($blogentry && $blogentry->publishstate != 'public' && !isloggedin()) {
  85         return false;
  86     }
  87
  88     // If blogentry is not passed or all above checks pass, then check capability based on system config.
  89     switch ($CFG->bloglevel) {
  90         case BLOG_GLOBAL_LEVEL:
  91             return true;
  92         break;
  93
  94         case BLOG_SITE_LEVEL:
  95             if (isloggedin()) { // Not logged in viewers forbidden.
  96                 return true;
  97             }
  98             return false;
  99         break;
 100
 101         case BLOG_USER_LEVEL:
 102         default:
 103             // If user is viewing other user blog, then user should have user:readuserblogs capability.
 104             $personalcontext = context_user::instance($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     $context = context_course::instance($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     $rss = new moodle_simplepie();
 151     $rssfile = $rss->registry->create('File', array($externalblog->url));
 152     $filetest = $rss->registry->create('Locator', array($rssfile));
 153
 154     if (!$filetest->is_feed($rssfile)) {
 155         $externalblog->failedlastsync = 1;
 156         $DB->update_record('blog_external', $externalblog);
 157         return false;
 158     } else if (!empty($externalblog->failedlastsync)) {
 159         $externalblog->failedlastsync = 0;
 160         $DB->update_record('blog_external', $externalblog);
 161     }
 162
 163     $rss->set_feed_url($externalblog->url);
 164     $rss->init();
 165
 166     if (empty($rss->data)) {
 167         return null;
 168     }
 169     // Used to identify blog posts that have been deleted from the source feed.
 170     $oldesttimestamp = null;
 171     $uniquehashes = array();
 172
 173     foreach ($rss->get_items() as $entry) {
 174         // If filtertags are defined, use them to filter the entries by RSS category.
 175         if (!empty($externalblog->filtertags)) {
 176             $containsfiltertag = false;
 177             $categories = $entry->get_categories();
 178             $filtertags = explode(',', $externalblog->filtertags);
 179             $filtertags = array_map('trim', $filtertags);
 180             $filtertags = array_map('strtolower', $filtertags);
 181
 182             if (!empty($categories)) {
 183                 foreach ($categories as $category) {
 184                     if (in_array(trim(strtolower($category->term)), $filtertags)) {
 185                         $containsfiltertag = true;
 186                     }
 187                 }
 188             }
 189
 190             if (!$containsfiltertag) {
 191                 continue;
 192             }
 193         }
 194
 195         $uniquehashes[] = $entry->get_permalink();
 196
 197         $newentry = new stdClass();
 198         $newentry->userid = $externalblog->userid;
 199         $newentry->module = 'blog_external';
 200         $newentry->content = $externalblog->id;
 201         $newentry->uniquehash = $entry->get_permalink();
 202         $newentry->publishstate = 'site';
 203         $newentry->format = FORMAT_HTML;
 204         // Clean subject of html, just in case.
 205         $newentry->subject = clean_param($entry->get_title(), PARAM_TEXT);
 206         // Observe 128 max chars in DB.
 207         // TODO: +1 to raise this to 255.
 208         if (core_text::strlen($newentry->subject) > 128) {
 209             $newentry->subject = core_text::substr($newentry->subject, 0, 125) . '...';
 210         }
 211         $newentry->summary = $entry->get_description();
 212
 213         // Used to decide whether to insert or update.
 214         // Uses enty permalink plus creation date if available.
 215         $existingpostconditions = array('uniquehash' => $entry->get_permalink());
 216
 217         // Our DB doesnt allow null creation or modified timestamps so check the external blog supplied one.
 218         $entrydate = $entry->get_date('U');
 219         if (!empty($entrydate)) {
 220             $existingpostconditions['created'] = $entrydate;
 221         }
 222
 223         // The post ID or false if post not found in DB.
 224         $postid = $DB->get_field('post', 'id', $existingpostconditions);
 225
 226         $timestamp = null;
 227         if (empty($entrydate)) {
 228             $timestamp = time();
 229         } else {
 230             $timestamp = $entrydate;
 231         }
 232
 233         // Only set created if its a new post so we retain the original creation timestamp if the post is edited.
 234         if ($postid === false) {
 235             $newentry->created = $timestamp;
 236         }
 237         $newentry->lastmodified = $timestamp;
 238
 239         if (empty($oldesttimestamp) || $timestamp < $oldesttimestamp) {
 240             // Found an older post.
 241             $oldesttimestamp = $timestamp;
 242         }
 243
 244         if (core_text::strlen($newentry->uniquehash) > 255) {
 245             // The URL for this item is too long for the field. Rather than add
 246             // the entry without the link we will skip straight over it.
 247             // RSS spec says recommended length 500, we use 255.
 248             debugging('External blog entry skipped because of oversized URL', DEBUG_DEVELOPER);
 249             continue;
 250         }
 251
 252         if ($postid === false) {
 253             $id = $DB->insert_record('post', $newentry);
 254
 255             // Set tags.
 256             if ($tags = core_tag_tag::get_item_tags_array('core', 'blog_external', $externalblog->id)) {
 257                 core_tag_tag::set_item_tags('core', 'post', $id, context_user::instance($externalblog->userid), $tags);
 258             }
 259         } else {
 260             $newentry->id = $postid;
 261             $DB->update_record('post', $newentry);
 262         }
 263     }
 264
 265     // Look at the posts we have in the database to check if any of them have been deleted from the feed.
 266     // Only checking posts within the time frame returned by the rss feed. Older items may have been deleted or
 267     // may just not be returned anymore. We can't tell the difference so we leave older posts alone.
 268     $sql = "SELECT id, uniquehash
 269               FROM {post}
 270              WHERE module = 'blog_external'
 271                    AND " . $DB->sql_compare_text('content') . " = " . $DB->sql_compare_text(':blogid') . "
 272                    AND created > :ts";
 273     $dbposts = $DB->get_records_sql($sql, array('blogid' => $externalblog->id, 'ts' => $oldesttimestamp));
 274
 275     $todelete = array();
 276     foreach ($dbposts as $dbpost) {
 277         if ( !in_array($dbpost->uniquehash, $uniquehashes) ) {
 278             $todelete[] = $dbpost->id;
 279         }
 280     }
 281     $DB->delete_records_list('post', 'id', $todelete);
 282
 283     $DB->update_record('blog_external', array('id' => $externalblog->id, 'timefetched' => time()));
 284 }
 285
 286 /**
 287  * Given an external blog object, deletes all related blog entries from the post table.
 288  * NOTE: The external blog's id is saved as post.content, a field that is not oterhwise used by blog entries.
 289  * @param object $externablog
 290  */
 291 function blog_delete_external_entries($externalblog) {
 292     global $DB;
 293     require_capability('moodle/blog:manageexternal', context_system::instance());
 294     $DB->delete_records_select('post',
 295                                "module='blog_external' AND " . $DB->sql_compare_text('content') . " = ?",
 296                                array($externalblog->id));
 297 }
 298
 299 /**
 300  * This function checks that blogs are enabled, and that the user can see blogs at all
 301  * @return bool
 302  */
 303 function blog_is_enabled_for_user() {
 304     global $CFG;
 305     return (!empty($CFG->enableblogs) && (isloggedin() || ($CFG->bloglevel == BLOG_GLOBAL_LEVEL)));
 306 }
 307
 308 /**
 309  * This function gets all of the options available for the current user in respect
 310  * to blogs.
 311  *
 312  * It loads the following if applicable:
 313  * -  Module options {@see blog_get_options_for_module}
 314  * -  Course options {@see blog_get_options_for_course}
 315  * -  User specific options {@see blog_get_options_for_user}
 316  * -  General options (BLOG_LEVEL_GLOBAL)
 317  *
 318  * @param moodle_page $page The page to load for (normally $PAGE)
 319  * @param stdClass $userid Load for a specific user
 320  * @return array An array of options organised by type.
 321  */
 322 function blog_get_all_options(moodle_page $page, stdClass $userid = null) {
 323     global $CFG, $DB, $USER;
 324
 325     $options = array();
 326
 327     // If blogs are enabled and the user is logged in and not a guest.
 328     if (blog_is_enabled_for_user()) {
 329         // If the context is the user then assume we want to load for the users context.
 330         if (is_null($userid) && $page->context->contextlevel == CONTEXT_USER) {
 331             $userid = $page->context->instanceid;
 332         }
 333         // Check the userid var.
 334         if (!is_null($userid) && $userid !== $USER->id) {
 335             // Load the user from the userid... it MUST EXIST throw a wobbly if it doesn't!
 336             $user = $DB->get_record('user', array('id' => $userid), '*', MUST_EXIST);
 337         } else {
 338             $user = null;
 339         }
 340
 341         if ($CFG->useblogassociations && $page->cm !== null) {
 342             // Load for the module associated with the page.
 343             $options[CONTEXT_MODULE] = blog_get_options_for_module($page->cm, $user);
 344         } else if ($CFG->useblogassociations && $page->course->id != SITEID) {
 345             // Load the options for the course associated with the page.
 346             $options[CONTEXT_COURSE] = blog_get_options_for_course($page->course, $user);
 347         }
 348
 349         // Get the options for the user.
 350         if ($user !== null and !isguestuser($user)) {
 351             // Load for the requested user.
 352             $options[CONTEXT_USER + 1] = blog_get_options_for_user($user);
 353         }
 354         // Load for the current user.
 355         if (isloggedin() and !isguestuser()) {
 356             $options[CONTEXT_USER] = blog_get_options_for_user();
 357         }
 358     }
 359
 360     // If blog level is global then display a link to view all site entries.
 361     if (!empty($CFG->enableblogs)
 362         && $CFG->bloglevel >= BLOG_GLOBAL_LEVEL
 363         && has_capability('moodle/blog:view', context_system::instance())) {
 364
 365         $options[CONTEXT_SYSTEM] = array('viewsite' => array(
 366             'string' => get_string('viewsiteentries', 'blog'),
 367             'link' => new moodle_url('/blog/index.php')
 368         ));
 369     }
 370
 371     // Return the options.
 372     return $options;
 373 }
 374
 375 /**
 376  * Get all of the blog options that relate to the passed user.
 377  *
 378  * If no user is passed the current user is assumed.
 379  *
 380  * @staticvar array $useroptions Cache so we don't have to regenerate multiple times
 381  * @param stdClass $user
 382  * @return array The array of options for the requested user
 383  */
 384 function blog_get_options_for_user(stdClass $user=null) {
 385     global $CFG, $USER;
 386     // Cache.
 387     static $useroptions = array();
 388
 389     $options = array();
 390     // Blogs must be enabled and the user must be logged in.
 391     if (!blog_is_enabled_for_user()) {
 392         return $options;
 393     }
 394
 395     // Sort out the user var.
 396     if ($user === null || $user->id == $USER->id) {
 397         $user = $USER;
 398         $iscurrentuser = true;
 399     } else {
 400         $iscurrentuser = false;
 401     }
 402
 403     // If we've already generated serve from the cache.
 404     if (array_key_exists($user->id, $useroptions)) {
 405         return $useroptions[$user->id];
 406     }
 407
 408     $sitecontext = context_system::instance();
 409     $canview = has_capability('moodle/blog:view', $sitecontext);
 410
 411     if (!$iscurrentuser && $canview && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 412         // Not the current user, but we can view and its blogs are enabled for SITE or GLOBAL.
 413         $options['userentries'] = array(
 414             'string' => get_string('viewuserentries', 'blog', fullname($user)),
 415             'link' => new moodle_url('/blog/index.php', array('userid' => $user->id))
 416         );
 417     } else {
 418         // It's the current user.
 419         if ($canview) {
 420             // We can view our own blogs .... BIG surprise.
 421             $options['view'] = array(
 422                 'string' => get_string('blogentries', 'blog'),
 423                 'link' => new moodle_url('/blog/index.php', array('userid' => $USER->id))
 424             );
 425         }
 426         if (has_capability('moodle/blog:create', $sitecontext)) {
 427             // We can add to our own blog.
 428             $options['add'] = array(
 429                 'string' => get_string('addnewentry', 'blog'),
 430                 'link' => new moodle_url('/blog/edit.php', array('action' => 'add'))
 431             );
 432         }
 433     }
 434     if ($canview && $CFG->enablerssfeeds) {
 435         $options['rss'] = array(
 436             'string' => get_string('rssfeed', 'blog'),
 437             'link' => new moodle_url(rss_get_url($sitecontext->id, $USER->id, 'blog', 'user/'.$user->id))
 438         );
 439     }
 440
 441     // Cache the options.
 442     $useroptions[$user->id] = $options;
 443     // Return the options.
 444     return $options;
 445 }
 446
 447 /**
 448  * Get the blog options that relate to the given course for the given user.
 449  *
 450  * @staticvar array $courseoptions A cache so we can save regenerating multiple times
 451  * @param stdClass $course The course to load options for
 452  * @param stdClass $user The user to load options for null == current user
 453  * @return array The array of options
 454  */
 455 function blog_get_options_for_course(stdClass $course, stdClass $user=null) {
 456     global $CFG, $USER;
 457     // Cache.
 458     static $courseoptions = array();
 459
 460     $options = array();
 461
 462     // User must be logged in and blogs must be enabled.
 463     if (!blog_is_enabled_for_user()) {
 464         return $options;
 465     }
 466
 467     // Check that the user can associate with the course.
 468     $sitecontext = context_system::instance();
 469     // Generate the cache key.
 470     $key = $course->id.':';
 471     if (!empty($user)) {
 472         $key .= $user->id;
 473     } else {
 474         $key .= $USER->id;
 475     }
 476     // Serve from the cache if we've already generated for this course.
 477     if (array_key_exists($key, $courseoptions)) {
 478         return $courseoptions[$key];
 479     }
 480
 481     if (has_capability('moodle/blog:view', $sitecontext)) {
 482         // We can view!
 483         if ($CFG->bloglevel >= BLOG_SITE_LEVEL) {
 484             // View entries about this course.
 485             $options['courseview'] = array(
 486                 'string' => get_string('viewcourseblogs', 'blog'),
 487                 'link' => new moodle_url('/blog/index.php', array('courseid' => $course->id))
 488             );
 489         }
 490         // View MY entries about this course.
 491         $options['courseviewmine'] = array(
 492             'string' => get_string('viewmyentriesaboutcourse', 'blog'),
 493             'link' => new moodle_url('/blog/index.php', array('courseid' => $course->id, 'userid' => $USER->id))
 494         );
 495         if (!empty($user) && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 496             // View the provided users entries about this course.
 497             $options['courseviewuser'] = array(
 498                 'string' => get_string('viewentriesbyuseraboutcourse', 'blog', fullname($user)),
 499                 'link' => new moodle_url('/blog/index.php', array('courseid' => $course->id, 'userid' => $user->id))
 500             );
 501         }
 502     }
 503
 504     if (has_capability('moodle/blog:create', $sitecontext)) {
 505         // We can blog about this course.
 506         $options['courseadd'] = array(
 507             'string' => get_string('blogaboutthiscourse', 'blog'),
 508             'link' => new moodle_url('/blog/edit.php', array('action' => 'add', 'courseid' => $course->id))
 509         );
 510     }
 511
 512     // Cache the options for this course.
 513     $courseoptions[$key] = $options;
 514     // Return the options.
 515     return $options;
 516 }
 517
 518 /**
 519  * Get the blog options relating to the given module for the given user
 520  *
 521  * @staticvar array $moduleoptions Cache
 522  * @param stdClass|cm_info $module The module to get options for
 523  * @param stdClass $user The user to get options for null == currentuser
 524  * @return array
 525  */
 526 function blog_get_options_for_module($module, $user=null) {
 527     global $CFG, $USER;
 528     // Cache.
 529     static $moduleoptions = array();
 530
 531     $options = array();
 532     // User must be logged in, blogs must be enabled.
 533     if (!blog_is_enabled_for_user()) {
 534         return $options;
 535     }
 536
 537     $sitecontext = context_system::instance();
 538
 539     // Generate the cache key.
 540     $key = $module->id.':';
 541     if (!empty($user)) {
 542         $key .= $user->id;
 543     } else {
 544         $key .= $USER->id;
 545     }
 546     if (array_key_exists($key, $moduleoptions)) {
 547         // Serve from the cache so we don't have to regenerate.
 548         return $moduleoptions[$key];
 549     }
 550
 551     if (has_capability('moodle/blog:view', $sitecontext)) {
 552         // Save correct module name for later usage.
 553         $modulename = get_string('modulename', $module->modname);
 554
 555         // We can view!
 556         if ($CFG->bloglevel >= BLOG_SITE_LEVEL) {
 557             // View all entries about this module.
 558             $a = new stdClass;
 559             $a->type = $modulename;
 560             $options['moduleview'] = array(
 561                 'string' => get_string('viewallmodentries', 'blog', $a),
 562                 'link' => new moodle_url('/blog/index.php', array('modid' => $module->id))
 563             );
 564         }
 565         // View MY entries about this module.
 566         $options['moduleviewmine'] = array(
 567             'string' => get_string('viewmyentriesaboutmodule', 'blog', $modulename),
 568             'link' => new moodle_url('/blog/index.php', array('modid' => $module->id, 'userid' => $USER->id))
 569         );
 570         if (!empty($user) && ($CFG->bloglevel >= BLOG_SITE_LEVEL)) {
 571             // View the given users entries about this module.
 572             $a = new stdClass;
 573             $a->mod = $modulename;
 574             $a->user = fullname($user);
 575             $options['moduleviewuser'] = array(
 576                 'string' => get_string('blogentriesbyuseraboutmodule', 'blog', $a),
 577                 'link' => new moodle_url('/blog/index.php', array('modid' => $module->id, 'userid' => $user->id))
 578             );
 579         }
 580     }
 581
 582     if (has_capability('moodle/blog:create', $sitecontext)) {
 583         // The user can blog about this module.
 584         $options['moduleadd'] = array(
 585             'string' => get_string('blogaboutthismodule', 'blog', $modulename),
 586             'link' => new moodle_url('/blog/edit.php', array('action' => 'add', 'modid' => $module->id))
 587         );
 588     }
 589     // Cache the options.
 590     $moduleoptions[$key] = $options;
 591     // Return the options.
 592     return $options;
 593 }
 594
 595 /**
 596  * This function encapsulates all the logic behind the complex
 597  * navigation, titles and headings of the blog listing page, depending
 598  * on URL params. It looks at URL params and at the current context level.
 599  * It builds and returns an array containing:
 600  *
 601  * 1. heading: The heading displayed above the blog entries
 602  * 2. stradd:  The text to be used as the "Add entry" link
 603  * 3. strview: The text to be used as the "View entries" link
 604  * 4. url:     The moodle_url object used as the base for add and view links
 605  * 5. filters: An array of parameters used to filter blog listings. Used by index.php and the Recent blogs block
 606  *
 607  * All other variables are set directly in $PAGE
 608  *
 609  * It uses the current URL to build these variables.
 610  * A number of mutually exclusive use cases are used to structure this function.
 611  *
 612  * @return array
 613  */
 614 function blog_get_headers($courseid=null, $groupid=null, $userid=null, $tagid=null) {
 615     global $CFG, $PAGE, $DB, $USER;
 616
 617     $id       = optional_param('id', null, PARAM_INT);
 618     $tag      = optional_param('tag', null, PARAM_NOTAGS);
 619     $tagid    = optional_param('tagid', $tagid, PARAM_INT);
 620     $userid   = optional_param('userid', $userid, PARAM_INT);
 621     $modid    = optional_param('modid', null, PARAM_INT);
 622     $entryid  = optional_param('entryid', null, PARAM_INT);
 623     $groupid  = optional_param('groupid', $groupid, PARAM_INT);
 624     $courseid = optional_param('courseid', $courseid, PARAM_INT);
 625     $search   = optional_param('search', null, PARAM_RAW);
 626     $action   = optional_param('action', null, PARAM_ALPHA);
 627     $confirm  = optional_param('confirm', false, PARAM_BOOL);
 628
 629     // Ignore userid when action == add.
 630     if ($action == 'add' && $userid) {
 631         unset($userid);
 632         $PAGE->url->remove_params(array('userid'));
 633     } else if ($action == 'add' && $entryid) {
 634         unset($entryid);
 635         $PAGE->url->remove_params(array('entryid'));
 636     }
 637
 638     $headers = array('title' => '', 'heading' => '', 'cm' => null, 'filters' => array());
 639
 640     $blogurl = new moodle_url('/blog/index.php');
 641
 642     $headers['stradd'] = get_string('addnewentry', 'blog');
 643     $headers['strview'] = null;
 644
 645     $site = $DB->get_record('course', array('id' => SITEID));
 646     $sitecontext = context_system::instance();
 647     // Common Lang strings.
 648     $strparticipants = get_string("participants");
 649     $strblogentries  = get_string("blogentries", 'blog');
 650
 651     // Prepare record objects as needed.
 652     if (!empty($courseid)) {
 653         $headers['filters']['course'] = $courseid;
 654         $course = $DB->get_record('course', array('id' => $courseid));
 655     }
 656
 657     if (!empty($userid)) {
 658         $headers['filters']['user'] = $userid;
 659         $user = $DB->get_record('user', array('id' => $userid));
 660     }
 661
 662     if (!empty($groupid)) { // The groupid always overrides courseid.
 663         $headers['filters']['group'] = $groupid;
 664         $group = $DB->get_record('groups', array('id' => $groupid));
 665         $course = $DB->get_record('course', array('id' => $group->courseid));
 666     }
 667
 668     $PAGE->set_pagelayout('standard');
 669
 670     // The modid always overrides courseid, so the $course object may be reset here.
 671     if (!empty($modid) && $CFG->useblogassociations) {
 672
 673         $headers['filters']['module'] = $modid;
 674         // A groupid param may conflict with this coursemod's courseid. Ignore groupid in that case.
 675         $courseid = $DB->get_field('course_modules', 'course', array('id' => $modid));
 676         $course = $DB->get_record('course', array('id' => $courseid));
 677         $cm = $DB->get_record('course_modules', array('id' => $modid));
 678         $cm->modname = $DB->get_field('modules', 'name', array('id' => $cm->module));
 679         $cm->name = $DB->get_field($cm->modname, 'name', array('id' => $cm->instance));
 680         $a = new stdClass();
 681         $a->type = get_string('modulename', $cm->modname);
 682         $PAGE->set_cm($cm, $course);
 683         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 684         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 685     }
 686
 687     // Case 1: No entry, mod, course or user params: all site entries to be shown (filtered by search and tag/tagid)
 688     // Note: if action is set to 'add' or 'edit', we do this at the end.
 689     if (empty($entryid) && empty($modid) && empty($courseid) && empty($userid) && !in_array($action, array('edit', 'add'))) {
 690         $PAGE->navbar->add($strblogentries, $blogurl);
 691         $PAGE->set_title($site->fullname);
 692         $PAGE->set_heading($site->fullname);
 693         $headers['heading'] = get_string('siteblogheading', 'blog');
 694     }
 695
 696     // Case 2: only entryid is requested, ignore all other filters. courseid is used to give more contextual information.
 697     if (!empty($entryid)) {
 698         $headers['filters']['entry'] = $entryid;
 699         $sql = 'SELECT u.* FROM {user} u, {post} p WHERE p.id = ? AND p.userid = u.id';
 700         $user = $DB->get_record_sql($sql, array($entryid));
 701         $entry = $DB->get_record('post', array('id' => $entryid));
 702
 703         $blogurl->param('userid', $user->id);
 704
 705         if (!empty($course)) {
 706             $mycourseid = $course->id;
 707             $blogurl->param('courseid', $mycourseid);
 708         } else {
 709             $mycourseid = $site->id;
 710         }
 711         $shortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 712
 713         $PAGE->navbar->add($strblogentries, $blogurl);
 714
 715         $blogurl->remove_params('userid');
 716         $PAGE->navbar->add($entry->subject, $blogurl);
 717         $PAGE->set_title("$shortname: " . fullname($user) . ": $entry->subject");
 718         $PAGE->set_heading("$shortname: " . fullname($user) . ": $entry->subject");
 719         $headers['heading'] = get_string('blogentrybyuser', 'blog', fullname($user));
 720
 721         // We ignore tag and search params.
 722         if (empty($action) || !$CFG->useblogassociations) {
 723             $headers['url'] = $blogurl;
 724             return $headers;
 725         }
 726     }
 727
 728     if (!empty($userid) && empty($entryid) && ((empty($courseid) && empty($modid)) || !$CFG->useblogassociations)) {
 729         // Case 3: A user's blog entries.
 730
 731         $shortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 732         $blogurl->param('userid', $userid);
 733         $PAGE->set_title("$shortname: " . fullname($user) . ": " . get_string('blog', 'blog'));
 734         $PAGE->set_heading("$shortname: " . fullname($user) . ": " . get_string('blog', 'blog'));
 735         $headers['heading'] = get_string('userblog', 'blog', fullname($user));
 736         $headers['strview'] = get_string('viewuserentries', 'blog', fullname($user));
 737
 738     } else if (!$CFG->useblogassociations && empty($userid) && !in_array($action, array('edit', 'add'))) {
 739         // Case 4: No blog associations, no userid.
 740
 741         $PAGE->set_title($site->fullname);
 742         $PAGE->set_heading($site->fullname);
 743         $headers['heading'] = get_string('siteblogheading', 'blog');
 744     } else if (!empty($userid) && !empty($modid) && empty($entryid)) {
 745         // Case 5: Blog entries associated with an activity by a specific user (courseid ignored).
 746
 747         $shortname = format_string($site->shortname, true, array('context' => context_course::instance(SITEID)));
 748         $blogurl->param('userid', $userid);
 749         $blogurl->param('modid', $modid);
 750
 751         // Course module navigation is handled by build_navigation as the second param.
 752         $headers['cm'] = $cm;
 753         $PAGE->navbar->add(fullname($user), "$CFG->wwwroot/user/view.php?id=$user->id");
 754         $PAGE->navbar->add($strblogentries, $blogurl);
 755
 756         $PAGE->set_title("$shortname: $cm->name: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 757         $PAGE->set_heading("$shortname: $cm->name: " . fullname($user) . ': ' . get_string('blogentries', 'blog'));
 758
 759         $a = new stdClass();
 760         $a->user = fullname($user);
 761         $a->mod = $cm->name;
 762         $a->type = get_string('modulename', $cm->modname);
 763         $headers['heading'] = get_string('blogentriesbyuseraboutmodule', 'blog', $a);
 764         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 765         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 766     } else if (!empty($userid) && !empty($courseid) && empty($modid) && empty($entryid)) {
 767         // Case 6: Blog entries associated with a course by a specific user.
 768
 769         $blogurl->param('userid', $userid);
 770         $blogurl->param('courseid', $courseid);
 771
 772         $PAGE->set_title($course->fullname);
 773         $PAGE->set_heading($course->fullname);
 774
 775         $a = new stdClass();
 776         $a->user = fullname($user);
 777         $a->course = format_string($course->fullname, true, array('context' => context_course::instance($course->id)));
 778         $a->type = get_string('course');
 779         $headers['heading'] = get_string('blogentriesbyuseraboutcourse', 'blog', $a);
 780         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 781         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 782
 783         // Remove the userid from the URL to inform the blog_menu block correctly.
 784         $blogurl->remove_params(array('userid'));
 785     } else if (!empty($groupid) && empty($modid) && empty($entryid)) {
 786         // Case 7: Blog entries by members of a group, associated with that group's course.
 787
 788         $blogurl->param('courseid', $course->id);
 789
 790         $PAGE->navbar->add($strblogentries, $blogurl);
 791         $blogurl->remove_params(array('courseid'));
 792         $blogurl->param('groupid', $groupid);
 793         $PAGE->navbar->add($group->name, $blogurl);
 794
 795         $PAGE->set_title($course->fullname);
 796         $PAGE->set_heading($course->fullname);
 797
 798         $a = new stdClass();
 799         $a->group = $group->name;
 800         $a->course = format_string($course->fullname, true, array('context' => context_course::instance($course->id)));
 801         $a->type = get_string('course');
 802         $headers['heading'] = get_string('blogentriesbygroupaboutcourse', 'blog', $a);
 803         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 804         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 805     } else if (!empty($groupid) && !empty($modid) && empty($entryid)) {
 806         // Case 8: Blog entries by members of a group, associated with an activity in that course.
 807
 808         $headers['cm'] = $cm;
 809         $blogurl->param('modid', $modid);
 810         $PAGE->navbar->add($strblogentries, $blogurl);
 811
 812         $blogurl->param('groupid', $groupid);
 813         $PAGE->navbar->add($group->name, $blogurl);
 814
 815         $PAGE->set_title($course->fullname);
 816         $PAGE->set_heading($course->fullname);
 817
 818         $a = new stdClass();
 819         $a->group = $group->name;
 820         $a->mod = $cm->name;
 821         $a->type = get_string('modulename', $cm->modname);
 822         $headers['heading'] = get_string('blogentriesbygroupaboutmodule', 'blog', $a);
 823         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 824         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 825
 826     } else if (!empty($modid) && empty($userid) && empty($groupid) && empty($entryid)) {
 827         // Case 9: All blog entries associated with an activity.
 828
 829         $PAGE->set_cm($cm, $course);
 830         $blogurl->param('modid', $modid);
 831         $PAGE->navbar->add($strblogentries, $blogurl);
 832         $PAGE->set_title($course->fullname);
 833         $PAGE->set_heading($course->fullname);
 834         $headers['heading'] = get_string('blogentriesabout', 'blog', $cm->name);
 835         $a = new stdClass();
 836         $a->type = get_string('modulename', $cm->modname);
 837         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 838         $headers['strview'] = get_string('viewallmodentries', 'blog', $a);
 839     } else if (!empty($courseid) && empty($userid) && empty($groupid) && empty($modid) && empty($entryid)) {
 840         // Case 10: All blog entries associated with a course.
 841
 842         $blogurl->param('courseid', $courseid);
 843         $PAGE->navbar->add($strblogentries, $blogurl);
 844         $PAGE->set_title($course->fullname);
 845         $PAGE->set_heading($course->fullname);
 846         $a = new stdClass();
 847         $a->type = get_string('course');
 848         $headers['heading'] = get_string('blogentriesabout',
 849                                          'blog',
 850                                          format_string($course->fullname,
 851                                                        true,
 852                                                        array('context' => context_course::instance($course->id))));
 853         $headers['stradd'] = get_string('blogaboutthis', 'blog', $a);
 854         $headers['strview'] = get_string('viewblogentries', 'blog', $a);
 855         $blogurl->remove_params(array('userid'));
 856     }
 857
 858     if (!in_array($action, array('edit', 'add'))) {
 859         // Append Tag info.
 860         if (!empty($tagid)) {
 861             $headers['filters']['tag'] = $tagid;
 862             $blogurl->param('tagid', $tagid);
 863             $tagrec = $DB->get_record('tag', array('id' => $tagid));
 864             $PAGE->navbar->add($tagrec->name, $blogurl);
 865         } else if (!empty($tag)) {
 866             if ($tagrec = $DB->get_record('tag', array('name' => $tag))) {
 867                 $tagid = $tagrec->id;
 868                 $headers['filters']['tag'] = $tagid;
 869                 $blogurl->param('tag', $tag);
 870                 $PAGE->navbar->add(get_string('tagparam', 'blog', $tag), $blogurl);
 871             }
 872         }
 873
 874         // Append Search info.
 875         if (!empty($search)) {
 876             $headers['filters']['search'] = $search;
 877             $blogurl->param('search', $search);
 878             $PAGE->navbar->add(get_string('searchterm', 'blog', $search), $blogurl->out());
 879         }
 880     }
 881
 882     // Append edit mode info.
 883     if (!empty($action) && $action == 'add') {
 884
 885     } else if (!empty($action) && $action == 'edit') {
 886         $PAGE->navbar->add(get_string('editentry', 'blog'));
 887     }
 888
 889     if (empty($headers['url'])) {
 890         $headers['url'] = $blogurl;
 891     }
 892     return $headers;
 893 }
 894
 895 /**
 896  * Shortcut function for getting a count of blog entries associated with a course or a module
 897  * @param int $courseid The ID of the course
 898  * @param int $cmid The ID of the course_modules
 899  * @return string The number of associated entries
 900  */
 901 function blog_get_associated_count($courseid, $cmid=null) {
 902     global $DB;
 903     $context = context_course::instance($courseid);
 904     if ($cmid) {
 905         $context = context_module::instance($cmid);
 906     }
 907     return $DB->count_records('blog_association', array('contextid' => $context->id));
 908 }
 909
 910 /**
 911  * Running addtional permission check on plugin, for example, plugins
 912  * may have switch to turn on/off comments option, this callback will
 913  * affect UI display, not like pluginname_comment_validate only throw
 914  * exceptions.
 915  * blog_comment_validate will be called before viewing/adding/deleting
 916  * comment, so don't repeat checks.
 917  * Capability check has been done in comment->check_permissions(), we
 918  * don't need to do it again here.
 919  *
 920  * @package  core_blog
 921  * @category comment
 922  *
 923  * @param stdClass $commentparam {
 924  *              context  => context the context object
 925  *              courseid => int course id
 926  *              cm       => stdClass course module object
 927  *              commentarea => string comment area
 928  *              itemid      => int itemid
 929  * }
 930  * @return array
 931  */
 932 function blog_comment_permissions($commentparam) {
 933     global $DB;
 934
 935     // If blog is public and current user is guest, then don't let him post comments.
 936     $blogentry = $DB->get_record('post', array('id' => $commentparam->itemid), 'publishstate', MUST_EXIST);
 937
 938     if ($blogentry->publishstate != 'public') {
 939         if (!isloggedin() || isguestuser()) {
 940             return array('post' => false, 'view' => true);
 941         }
 942     }
 943     return array('post' => true, 'view' => true);
 944 }
 945
 946 /**
 947  * Validate comment parameter before perform other comments actions
 948  *
 949  * @package  core_blog
 950  * @category comment
 951  *
 952  * @param stdClass $comment {
 953  *              context  => context the context object
 954  *              courseid => int course id
 955  *              cm       => stdClass course module object
 956  *              commentarea => string comment area
 957  *              itemid      => int itemid
 958  * }
 959  * @return boolean
 960  */
 961 function blog_comment_validate($commentparam) {
 962     global $CFG, $DB, $USER;
 963
 964     // Check if blogs are enabled user can comment.
 965     if (empty($CFG->enableblogs) || empty($CFG->blogusecomments)) {
 966         throw new comment_exception('nopermissiontocomment');
 967     }
 968
 969     // Validate comment area.
 970     if ($commentparam->commentarea != 'format_blog') {
 971         throw new comment_exception('invalidcommentarea');
 972     }
 973
 974     $blogentry = $DB->get_record('post', array('id' => $commentparam->itemid), '*', MUST_EXIST);
 975
 976     // Validation for comment deletion.
 977     if (!empty($commentparam->commentid)) {
 978         if ($record = $DB->get_record('comments', array('id' => $commentparam->commentid))) {
 979             if ($record->commentarea != 'format_blog') {
 980                 throw new comment_exception('invalidcommentarea');
 981             }
 982             if ($record->contextid != $commentparam->context->id) {
 983                 throw new comment_exception('invalidcontext');
 984             }
 985             if ($record->itemid != $commentparam->itemid) {
 986                 throw new comment_exception('invalidcommentitemid');
 987             }
 988         } else {
 989             throw new comment_exception('invalidcommentid');
 990         }
 991     }
 992
 993     // Validate if user has blog view permission.
 994     $sitecontext = context_system::instance();
 995     return has_capability('moodle/blog:view', $sitecontext) &&
 996             blog_user_can_view_user_entry($blogentry->userid, $blogentry);
 997 }
 998
 999 /**
1000  * Return a list of page types
1001  * @param string $pagetype current page type
1002  * @param stdClass $parentcontext Block's parent context
1003  * @param stdClass $currentcontext Current context of block
1004  */
1005 function blog_page_type_list($pagetype, $parentcontext, $currentcontext) {
1006     return array(
1007         '*' => get_string('page-x', 'pagetype'),
1008         'blog-*' => get_string('page-blog-x', 'blog'),
1009         'blog-index' => get_string('page-blog-index', 'blog'),
1010         'blog-edit' => get_string('page-blog-edit', 'blog')
1011     );
1012 }
1013
1014 /**
1015  * Add nodes to myprofile page.
1016  *
1017  * @param \core_user\output\myprofile\tree $tree Tree object
1018  * @param stdClass $user user object
1019  * @param bool $iscurrentuser
1020  * @param stdClass $course Course object
1021  *
1022  * @return bool
1023  */
1024 function core_blog_myprofile_navigation(core_user\output\myprofile\tree $tree, $user, $iscurrentuser, $course) {
1025     global $CFG;
1026     if (!blog_is_enabled_for_user() || isguestuser($user)) {
1027         // The guest user cannot post, so it is not possible to view any posts.
1028         // Also blogs might be disabled.
1029         // May as well just bail aggressively here.
1030         return true;
1031     }
1032     if (!blog_user_can_view_user_entry($user->id)) {
1033         return true;
1034     }
1035     $url = new moodle_url("/blog/index.php", array('userid' => $user->id));
1036     if (!empty($course)) {
1037         $url->param('courseid', $course->id);
1038     }
1039     if ($iscurrentuser) {
1040         $title = get_string('blogentries', 'core_blog');
1041     } else {
1042         $title = get_string('myprofileuserblogs', 'core_blog');
1043     }
1044     $blognode = new core_user\output\myprofile\node('miscellaneous', 'blogs', $title, null, $url);
1045     $tree->add_node($blognode);
1046     return true;
1047 }
1048
1049 /**
1050  * Returns posts tagged with a specified tag.
1051  *
1052  * @param core_tag_tag $tag
1053  * @param bool $exclusivemode if set to true it means that no other entities tagged with this tag
1054  *             are displayed on the page and the per-page limit may be bigger
1055  * @param int $fromctx context id where the link was displayed, may be used by callbacks
1056  *            to display items in the same context first
1057  * @param int $ctx context id where to search for records
1058  * @param bool $rec search in subcontexts as well
1059  * @param int $page 0-based number of page being displayed
1060  * @return \core_tag\output\tagindex
1061  */
1062 function blog_get_tagged_posts($tag, $exclusivemode = false, $fromctx = 0, $ctx = 0, $rec = true, $page = 0) {
1063     global $CFG, $OUTPUT;
1064     require_once($CFG->dirroot.'/user/lib.php');
1065
1066     $systemcontext = context_system::instance();
1067     $perpage = $exclusivemode ? 20 : 5;
1068     $context = $ctx ? context::instance_by_id($ctx) : context_system::instance();
1069
1070     $content = '';
1071     if (empty($CFG->enableblogs) || !has_capability('moodle/blog:view', $systemcontext)) {
1072         // Blogs are not enabled or are not visible to the current user.
1073         $totalpages = 0;
1074     } else if ($context->contextlevel != CONTEXT_SYSTEM && empty($CFG->useblogassociations)) {
1075         // No blog entries can be associated to the non-system context.
1076         $totalpages = 0;
1077     } else if (!$rec && $context->contextlevel != CONTEXT_COURSE && $context->contextlevel != CONTEXT_MODULE) {
1078         // No blog entries can be associated with category or block context.
1079         $totalpages = 0;
1080     } else {
1081         require_once($CFG->dirroot.'/blog/locallib.php');
1082
1083         $filters = array('tag' => $tag->id);
1084         if ($rec) {
1085             if ($context->contextlevel != CONTEXT_SYSTEM) {
1086                 $filters['context'] = $context->id;
1087             }
1088         } else if ($context->contextlevel == CONTEXT_COURSE) {
1089             $filters['course'] = $context->instanceid;
1090         } else if ($context->contextlevel == CONTEXT_MODULE) {
1091             $filters['module'] = $context->instanceid;
1092         }
1093         $bloglisting = new blog_listing($filters);
1094         $blogs = $bloglisting->get_entries($page * $perpage, $perpage);
1095         $totalcount = $bloglisting->count_entries();
1096         $totalpages = ceil($totalcount / $perpage);
1097         if (!empty($blogs)) {
1098             $tagfeed = new core_tag\output\tagfeed();
1099             foreach ($blogs as $blog) {
1100                 $user = fullclone($blog);
1101                 $user->id = $blog->userid;
1102                 $user->deleted = 0;
1103                 $img = $OUTPUT->user_picture($user, array('size' => 35));
1104                 $subject = format_string($blog->subject);
1105
1106                 if ($blog->publishstate == 'draft') {
1107                     $class = 'dimmed';
1108                 } else {
1109                     $class = '';
1110                 }
1111
1112                 $url = new moodle_url('/blog/index.php', array('entryid' => $blog->id));
1113                 $subject = html_writer::link($url, $subject, array('class' => $class));
1114
1115                 $fullname = fullname($user);
1116                 if (user_can_view_profile($user)) {
1117                     $profilelink = new moodle_url('/user/view.php', array('id' => $blog->userid));
1118                     $fullname = html_writer::link($profilelink, $fullname);
1119                 }
1120                 $details = $fullname . ', ' . userdate($blog->created);
1121
1122                 $tagfeed->add($img, $subject, $details);
1123             }
1124
1125             $items = $tagfeed->export_for_template($OUTPUT);
1126             $content = $OUTPUT->render_from_template('core_tag/tagfeed', $items);
1127
1128             $urlparams = array('tagid' => $tag->id);
1129             if ($context->contextlevel == CONTEXT_COURSE) {
1130                 $urlparams['courseid'] = $context->instanceid;
1131             } else if ($context->contextlevel == CONTEXT_MODULE) {
1132                 $urlparams['modid'] = $context->instanceid;
1133             }
1134             $allblogsurl = new moodle_url('/blog/index.php', $urlparams);
1135
1136             $rv = new core_tag\output\tagindex($tag, 'core', 'post',
1137                     $content,
1138                     $exclusivemode, $fromctx, $ctx, $rec, $page, $totalpages);
1139             $rv->exclusiveurl = $allblogsurl;
1140             return $rv;
1141         }
1142     }
1143
1144     $rv = new core_tag\output\tagindex($tag, 'core', 'post',
1145             $content,
1146             $exclusivemode, $fromctx, $ctx, $rec, $page, $totalpages);
1147     $rv->exclusiveurl = null;
1148     return $rv;
1149 }