if ($mode) {
    set_user_preference('forum_displaymode', $mode);
}
$displaymode = get_user_preferences('forum_displaymode', $CFG->forum_displaymode);
if ($parent) {
    // If flat AND parent, then force nested display this time
    if ($displaymode == FORUM_MODE_FLATOLDEST or $displaymode == FORUM_MODE_FLATNEWEST) {
        $displaymode = FORUM_MODE_NESTED;
    }
} else {
    $parent = $discussion->firstpost;
}
if (!($post = forum_get_post_full($parent))) {
    print_error("notexists", 'forum', "{$CFG->wwwroot}/mod/forum/view.php?f={$forum->id}");
}
if (!forum_user_can_see_post($forum, $discussion, $post, null, $cm)) {
    print_error('noviewdiscussionspermission', 'forum', "{$CFG->wwwroot}/mod/forum/view.php?id={$forum->id}");
}
if ($mark == 'read' or $mark == 'unread') {
    if ($CFG->forum_usermarksread && forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {
        if ($mark == 'read') {
            forum_tp_add_read_record($USER->id, $postid);
        } else {
            // unread
            forum_tp_delete_read_records($USER->id, $postid);
        }
    }
}
$searchform = forum_search_form($course);
$forumnode = $PAGE->navigation->find($cm->id, navigation_node::TYPE_ACTIVITY);
if (empty($forumnode)) {

/**
 * @todo Document this function
 *
 * @global object
 * @global object
 * @uses CONTEXT_MODULE
 * @return void
 */
function forum_print_posts_threaded($course, &$cm, $forum, $discussion, $parent, $depth, $reply, $forumtracked, $posts) {
    global $USER, $CFG;

    $link  = false;

    if (!empty($posts[$parent->id]->children)) {
        $posts = $posts[$parent->id]->children;

        $modcontext       = context_module::instance($cm->id);
        $canviewfullnames = has_capability('moodle/site:viewfullnames', $modcontext);

        foreach ($posts as $post) {

            echo '<div class="indent">';
            if ($depth > 0) {
                $ownpost = ($USER->id == $post->userid);
                $post->subject = format_string($post->subject);

                $postread = !empty($post->postread);

                forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, $link,
                                     '', '', $postread, true, $forumtracked);
            } else {
                if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {
                    echo "</div>\n";
                    continue;
                }
                $by = new stdClass();
                $by->name = fullname($post, $canviewfullnames);
                $by->date = userdate($post->modified);

                if ($forumtracked) {
                    if (!empty($post->postread)) {
                        $style = '<span class="forumthread read">';
                    } else {
                        $style = '<span class="forumthread unread">';
                    }
                } else {
                    $style = '<span class="forumthread">';
                }
                echo $style."<a name=\"$post->id\"></a>".
                     "<a href=\"discuss.php?d=$post->discussion&amp;parent=$post->id\">".format_string($post->subject,true)."</a> ";
                print_string("bynameondate", "forum", $by);
                echo "</span>";
            }

            forum_print_posts_threaded($course, $cm, $forum, $discussion, $post, $depth-1, $reply, $forumtracked, $posts);
            echo "</div>\n";
        }
    }
}

}
if ($edit) {
    $PAGE->navbar->add(get_string('edit', 'forum'));
}
$PAGE->set_title("{$course->shortname}: {$strdiscussionname} " . format_string($toppost->subject));
$PAGE->set_heading($course->fullname);
// #marginalia begin
$moodlemia = moodle_marginalia::get_instance();
$miaprofile = $moodlemia->get_profile($PAGE->url->out(false));
if ($miaprofile) {
    $miaprofile->emit_requires($moodlemia);
}
// #marginalia end
echo $OUTPUT->header();
// checkup
if (!empty($parent) && !forum_user_can_see_post($forum, $discussion, $post, null, $cm)) {
    print_error('cannotreply', 'forum');
}
if (empty($parent) && empty($edit) && !forum_user_can_post_discussion($forum, $groupid, -1, $cm, $modcontext)) {
    print_error('cannotcreatediscussion', 'forum');
}
if ($forum->type == 'qanda' && !has_capability('mod/forum:viewqandawithoutposting', $modcontext) && !empty($discussion->id) && !forum_user_has_posted($forum->id, $discussion->id, $USER->id)) {
    echo $OUTPUT->notification(get_string('qandanotify', 'forum'));
}
forum_check_throttling($forum, $cm);
if (!empty($parent)) {
    if (!($discussion = $DB->get_record('forum_discussions', array('id' => $parent->discussion)))) {
        print_error('notpartofdiscussion', 'forum');
    }
    // #marginalia begin
    $moodlemia = moodle_marginalia::get_instance();

 /**
  * Whether the user can access the document or not.
  *
  * @throws \dml_missing_record_exception
  * @throws \dml_exception
  * @param int $id Forum post id
  * @return bool
  */
 public function check_access($id)
 {
     global $USER;
     try {
         $post = $this->get_post($id);
         $forum = $this->get_forum($post->forum);
         $discussion = $this->get_discussion($post->discussion);
         $cminfo = $this->get_cm('forum', $forum->id, $forum->course);
         $cm = $cminfo->get_course_module_record();
     } catch (\dml_missing_record_exception $ex) {
         return \core_search\manager::ACCESS_DELETED;
     } catch (\dml_exception $ex) {
         return \core_search\manager::ACCESS_DENIED;
     }
     // Recheck uservisible although it should have already been checked in core_search.
     if ($cminfo->uservisible === false) {
         return \core_search\manager::ACCESS_DENIED;
     }
     if (!forum_user_can_see_post($forum, $discussion, $post, $USER, $cm)) {
         return \core_search\manager::ACCESS_DENIED;
     }
     return \core_search\manager::ACCESS_GRANTED;
 }

/**
 * This function return the XML rss contents about the forum
 * It returns false if something is wrong
 *
 * @param stdClass $forum the forum object
 * @param string $sql the SQL used to retrieve the contents from the database
 * @param array $params the SQL parameters used
 * @param object $context the context this forum relates to
 * @return bool|string false if the contents is empty, otherwise the contents of the feed is returned
 *
 * @Todo MDL-31129 implement post attachment handling
 */

function forum_rss_feed_contents($forum, $sql, $params, $context) {
    global $CFG, $DB, $USER;

    $status = true;

    $recs = $DB->get_recordset_sql($sql, $params, 0, $forum->rssarticles);

    //set a flag. Are we displaying discussions or posts?
    $isdiscussion = true;
    if (!empty($forum->rsstype) && $forum->rsstype!=1) {
        $isdiscussion = false;
    }

    if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
        print_error('invalidcoursemodule');
    }

    $formatoptions = new stdClass();
    $items = array();
    foreach ($recs as $rec) {
            $item = new stdClass();
            $user = new stdClass();

            $discussion = new stdClass();
            $discussion->id = $rec->discussionid;
            $discussion->groupid = $rec->groupid;
            $discussion->timestart = $rec->timestart;
            $discussion->timeend = $rec->timeend;

            $post = null;
            if (!$isdiscussion) {
                $post = new stdClass();
                $post->id = $rec->postid;
                $post->parent = $rec->postparent;
                $post->userid = $rec->userid;
            }

            if ($isdiscussion && !forum_user_can_see_discussion($forum, $discussion, $context)) {
                // This is a discussion which the user has no permission to view
                $item->title = get_string('forumsubjecthidden', 'forum');
                $message = get_string('forumbodyhidden', 'forum');
                $item->author = get_string('forumauthorhidden', 'forum');
            } else if (!$isdiscussion && !forum_user_can_see_post($forum, $discussion, $post, $USER, $cm)) {
                // This is a post which the user has no permission to view
                $item->title = get_string('forumsubjecthidden', 'forum');
                $message = get_string('forumbodyhidden', 'forum');
                $item->author = get_string('forumauthorhidden', 'forum');
            } else {
                // The user must have permission to view
                if ($isdiscussion && !empty($rec->discussionname)) {
                    $item->title = format_string($rec->discussionname);
                } else if (!empty($rec->postsubject)) {
                    $item->title = format_string($rec->postsubject);
                } else {
                    //we should have an item title by now but if we dont somehow then substitute something somewhat meaningful
                    $item->title = format_string($forum->name.' '.userdate($rec->postcreated,get_string('strftimedatetimeshort', 'langconfig')));
                }
                $user->firstname = $rec->userfirstname;
                $user->lastname = $rec->userlastname;
                $item->author = fullname($user);
                $message = file_rewrite_pluginfile_urls($rec->postmessage, 'pluginfile.php', $context->id,
                        'mod_forum', 'post', $rec->postid);
                $formatoptions->trusted = $rec->posttrust;
            }

            if ($isdiscussion) {
                $item->link = $CFG->wwwroot."/mod/forum/discuss.php?d=".$rec->discussionid;
            } else {
                $item->link = $CFG->wwwroot."/mod/forum/discuss.php?d=".$rec->discussionid."&parent=".$rec->postid;
            }

            $formatoptions->trusted = $rec->posttrust;
            $item->description = format_text($message, $rec->postformat, $formatoptions, $forum->course);

            //TODO: MDL-31129 implement post attachment handling
            /*if (!$isdiscussion) {
                $post_file_area_name = str_replace('//', '/', "$forum->course/$CFG->moddata/forum/$forum->id/$rec->postid");
                $post_files = get_directory_list("$CFG->dataroot/$post_file_area_name");

                if (!empty($post_files)) {
                    $item->attachments = array();
                }
            }*/
            $item->pubdate = $rec->postcreated;

            $items[] = $item;
        }
//.........这里部分代码省略.........

 /**
  * Returns a list of forum posts for a discussion
  *
  * @param int $discussionid the post ids
  * @param string $sortby sort by this element (id, created or modified)
  * @param string $sortdirection sort direction: ASC or DESC
  *
  * @return array the forum post details
  * @since Moodle 2.7
  */
 public static function get_forum_discussion_posts($discussionid, $sortby = "created", $sortdirection = "DESC")
 {
     global $CFG, $DB, $USER;
     $warnings = array();
     // Validate the parameter.
     $params = self::validate_parameters(self::get_forum_discussion_posts_parameters(), array('discussionid' => $discussionid, 'sortby' => $sortby, 'sortdirection' => $sortdirection));
     // Compact/extract functions are not recommended.
     $discussionid = $params['discussionid'];
     $sortby = $params['sortby'];
     $sortdirection = $params['sortdirection'];
     $sortallowedvalues = array('id', 'created', 'modified');
     if (!in_array($sortby, $sortallowedvalues)) {
         throw new invalid_parameter_exception('Invalid value for sortby parameter (value: ' . $sortby . '),' . 'allowed values are: ' . implode(',', $sortallowedvalues));
     }
     $sortdirection = strtoupper($sortdirection);
     $directionallowedvalues = array('ASC', 'DESC');
     if (!in_array($sortdirection, $directionallowedvalues)) {
         throw new invalid_parameter_exception('Invalid value for sortdirection parameter (value: ' . $sortdirection . '),' . 'allowed values are: ' . implode(',', $directionallowedvalues));
     }
     $discussion = $DB->get_record('forum_discussions', array('id' => $discussionid), '*', MUST_EXIST);
     $forum = $DB->get_record('forum', array('id' => $discussion->forum), '*', MUST_EXIST);
     $course = $DB->get_record('course', array('id' => $forum->course), '*', MUST_EXIST);
     $cm = get_coursemodule_from_instance('forum', $forum->id, $course->id, false, MUST_EXIST);
     // Validate the module context. It checks everything that affects the module visibility (including groupings, etc..).
     $modcontext = context_module::instance($cm->id);
     self::validate_context($modcontext);
     // This require must be here, see mod/forum/discuss.php.
     require_once $CFG->dirroot . "/mod/forum/lib.php";
     // Check they have the view forum capability.
     require_capability('mod/forum:viewdiscussion', $modcontext, null, true, 'noviewdiscussionspermission', 'forum');
     if (!($post = forum_get_post_full($discussion->firstpost))) {
         throw new moodle_exception('notexists', 'forum');
     }
     // This function check groups, qanda, timed discussions, etc.
     if (!forum_user_can_see_post($forum, $discussion, $post, null, $cm)) {
         throw new moodle_exception('noviewdiscussionspermission', 'forum');
     }
     $canviewfullname = has_capability('moodle/site:viewfullnames', $modcontext);
     // We will add this field in the response.
     $canreply = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);
     $forumtracked = forum_tp_is_tracked($forum);
     $sort = 'p.' . $sortby . ' ' . $sortdirection;
     $posts = forum_get_all_discussion_posts($discussion->id, $sort, $forumtracked);
     foreach ($posts as $pid => $post) {
         if (!forum_user_can_see_post($forum, $discussion, $post, null, $cm)) {
             $warning = array();
             $warning['item'] = 'post';
             $warning['itemid'] = $post->id;
             $warning['warningcode'] = '1';
             $warning['message'] = 'You can\'t see this post';
             $warnings[] = $warning;
             continue;
         }
         // Function forum_get_all_discussion_posts adds postread field.
         // Note that the value returned can be a boolean or an integer. The WS expects a boolean.
         if (empty($post->postread)) {
             $posts[$pid]->postread = false;
         } else {
             $posts[$pid]->postread = true;
         }
         $posts[$pid]->canreply = $canreply;
         if (!empty($posts[$pid]->children)) {
             $posts[$pid]->children = array_keys($posts[$pid]->children);
         } else {
             $posts[$pid]->children = array();
         }
         $user = new stdclass();
         $user = username_load_fields_from_object($user, $post);
         $posts[$pid]->userfullname = fullname($user, $canviewfullname);
         $posts[$pid] = (array) $post;
     }
     $result = array();
     $result['posts'] = $posts;
     $result['warnings'] = $warnings;
     return $result;
 }

/**
 * Checks to see if a user can view a particular post.
 *
 * @deprecated since Moodle 2.4 use forum_user_can_see_post() instead
 *
 * @param object $post
 * @param object $course
 * @param object $cm
 * @param object $forum
 * @param object $discussion
 * @param object $user
 * @return boolean
 */
function forum_user_can_view_post($post, $course, $cm, $forum, $discussion, $user = null)
{
    debugging('forum_user_can_view_post() is deprecated. Please use forum_user_can_see_post() instead.', DEBUG_DEVELOPER);
    return forum_user_can_see_post($forum, $discussion, $post, $user, $cm);
}

    /**
     * Returns a list of forum posts for a discussion
     *
     * @param int $discussionid the post ids
     * @param string $sortby sort by this element (id, created or modified)
     * @param string $sortdirection sort direction: ASC or DESC
     *
     * @return array the forum post details
     * @since Moodle 2.7
     */
    public static function get_forum_discussion_posts($discussionid, $sortby = "created", $sortdirection = "DESC") {
        global $CFG, $DB, $USER;

        $posts = array();
        $warnings = array();

        // Validate the parameter.
        $params = self::validate_parameters(self::get_forum_discussion_posts_parameters(),
            array(
                'discussionid' => $discussionid,
                'sortby' => $sortby,
                'sortdirection' => $sortdirection));

        // Compact/extract functions are not recommended.
        $discussionid   = $params['discussionid'];
        $sortby         = $params['sortby'];
        $sortdirection  = $params['sortdirection'];

        $sortallowedvalues = array('id', 'created', 'modified');
        if (!in_array($sortby, $sortallowedvalues)) {
            throw new invalid_parameter_exception('Invalid value for sortby parameter (value: ' . $sortby . '),' .
                'allowed values are: ' . implode(',', $sortallowedvalues));
        }

        $sortdirection = strtoupper($sortdirection);
        $directionallowedvalues = array('ASC', 'DESC');
        if (!in_array($sortdirection, $directionallowedvalues)) {
            throw new invalid_parameter_exception('Invalid value for sortdirection parameter (value: ' . $sortdirection . '),' .
                'allowed values are: ' . implode(',', $directionallowedvalues));
        }

        $discussion = $DB->get_record('forum_discussions', array('id' => $discussionid), '*', MUST_EXIST);
        $forum = $DB->get_record('forum', array('id' => $discussion->forum), '*', MUST_EXIST);
        $course = $DB->get_record('course', array('id' => $forum->course), '*', MUST_EXIST);
        $cm = get_coursemodule_from_instance('forum', $forum->id, $course->id, false, MUST_EXIST);

        // Validate the module context. It checks everything that affects the module visibility (including groupings, etc..).
        $modcontext = context_module::instance($cm->id);
        self::validate_context($modcontext);

        // This require must be here, see mod/forum/discuss.php.
        require_once($CFG->dirroot . "/mod/forum/lib.php");

        // Check they have the view forum capability.
        require_capability('mod/forum:viewdiscussion', $modcontext, null, true, 'noviewdiscussionspermission', 'forum');

        if (! $post = forum_get_post_full($discussion->firstpost)) {
            throw new moodle_exception('notexists', 'forum');
        }

        // This function check groups, qanda, timed discussions, etc.
        if (!forum_user_can_see_post($forum, $discussion, $post, null, $cm)) {
            throw new moodle_exception('noviewdiscussionspermission', 'forum');
        }

        $canviewfullname = has_capability('moodle/site:viewfullnames', $modcontext);

        // We will add this field in the response.
        $canreply = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);

        $forumtracked = forum_tp_is_tracked($forum);

        $sort = 'p.' . $sortby . ' ' . $sortdirection;
        $allposts = forum_get_all_discussion_posts($discussion->id, $sort, $forumtracked);

        foreach ($allposts as $post) {

            if (!forum_user_can_see_post($forum, $discussion, $post, null, $cm)) {
                $warning = array();
                $warning['item'] = 'post';
                $warning['itemid'] = $post->id;
                $warning['warningcode'] = '1';
                $warning['message'] = 'You can\'t see this post';
                $warnings[] = $warning;
                continue;
            }

            // Function forum_get_all_discussion_posts adds postread field.
            // Note that the value returned can be a boolean or an integer. The WS expects a boolean.
            if (empty($post->postread)) {
                $post->postread = false;
            } else {
                $post->postread = true;
            }

            $post->canreply = $canreply;
            if (!empty($post->children)) {
                $post->children = array_keys($post->children);
            } else {
                $post->children = array();
//.........这里部分代码省略.........