//.........这里部分代码省略.........
    echo '<td class="' . $topicclass . '">';
    if (FORUM_DISCUSSION_PINNED == $post->pinned) {
        echo $OUTPUT->pix_icon('i/pinned', get_string('discussionpinned', 'forum'), 'mod_forum');
    }
    $canalwaysseetimedpost = $USER->id == $post->userid || $canviewhiddentimedposts;
    if ($timeddiscussion && $canalwaysseetimedpost) {
        echo $PAGE->get_renderer('mod_forum')->timed_discussion_tooltip($post, empty($timedoutsidewindow));
    }
    echo '<a href="' . $CFG->wwwroot . '/mod/forum/discuss.php?d=' . $post->discussion . '">' . $post->subject . '</a>';
    echo "</td>\n";
    // Picture
    $postuser = new stdClass();
    $postuserfields = explode(',', user_picture::fields());
    $postuser = username_load_fields_from_object($postuser, $post, null, $postuserfields);
    $postuser->id = $post->userid;
    echo '<td class="picture">';
    echo $OUTPUT->user_picture($postuser, array('courseid' => $forum->course));
    echo "</td>\n";
    // User name
    $fullname = fullname($postuser, has_capability('moodle/site:viewfullnames', $modcontext));
    echo '<td class="author">';
    echo '<a href="' . $CFG->wwwroot . '/user/view.php?id=' . $post->userid . '&amp;course=' . $forum->course . '">' . $fullname . '</a>';
    echo "</td>\n";
    // Group picture
    if ($group !== -1) {
        // Groups are active - group is a group data object or NULL
        echo '<td class="picture group">';
        if (!empty($group->picture) and empty($group->hidepicture)) {
            if ($canviewparticipants && $COURSE->groupmode) {
                $picturelink = true;
            } else {
                $picturelink = false;
            }
            print_group_picture($group, $forum->course, false, false, $picturelink);
        } else {
            if (isset($group->id)) {
                if ($canviewparticipants && $COURSE->groupmode) {
                    echo '<a href="' . $CFG->wwwroot . '/user/index.php?id=' . $forum->course . '&amp;group=' . $group->id . '">' . $group->name . '</a>';
                } else {
                    echo $group->name;
                }
            }
        }
        echo "</td>\n";
    }
    if (has_capability('mod/forum:viewdiscussion', $modcontext)) {
        // Show the column with replies
        echo '<td class="replies">';
        echo '<a href="' . $CFG->wwwroot . '/mod/forum/discuss.php?d=' . $post->discussion . '">';
        echo $post->replies . '</a>';
        echo "</td>\n";
        if ($cantrack) {
            echo '<td class="replies">';
            if ($forumtracked) {
                if ($post->unread > 0) {
                    echo '<span class="unread">';
                    echo '<a href="' . $CFG->wwwroot . '/mod/forum/discuss.php?d=' . $post->discussion . '#unread">';
                    echo $post->unread;
                    echo '</a>';
                    echo '<a title="' . $strmarkalldread . '" href="' . $CFG->wwwroot . '/mod/forum/markposts.php?f=' . $forum->id . '&amp;d=' . $post->discussion . '&amp;mark=read&amp;returnpage=view.php&amp;sesskey=' . sesskey() . '">' . '<img src="' . $OUTPUT->pix_url('t/markasread') . '" class="iconsmall" alt="' . $strmarkalldread . '" /></a>';
                    echo '</span>';
                } else {
                    echo '<span class="read">';
                    echo $post->unread;
                    echo '</span>';
                }
            } else {
                echo '<span class="read">';
                echo '-';
                echo '</span>';
            }
            echo "</td>\n";
        }
    }
    echo '<td class="lastpost">';
    $usedate = empty($post->timemodified) ? $post->modified : $post->timemodified;
    // Just in case
    $parenturl = '';
    $usermodified = new stdClass();
    $usermodified->id = $post->usermodified;
    $usermodified = username_load_fields_from_object($usermodified, $post, 'um');
    // In QA forums we check that the user can view participants.
    if ($forum->type !== 'qanda' || $canviewparticipants) {
        echo '<a href="' . $CFG->wwwroot . '/user/view.php?id=' . $post->usermodified . '&amp;course=' . $forum->course . '">' . fullname($usermodified) . '</a><br />';
        $parenturl = empty($post->lastpostid) ? '' : '&amp;parent=' . $post->lastpostid;
    }
    echo '<a href="' . $CFG->wwwroot . '/mod/forum/discuss.php?d=' . $post->discussion . $parenturl . '">' . userdate($usedate, $datestring) . '</a>';
    echo "</td>\n";
    // is_guest should be used here as this also checks whether the user is a guest in the current course.
    // Guests and visitors cannot subscribe - only enrolled users.
    if (!is_guest($modcontext, $USER) && isloggedin() && has_capability('mod/forum:viewdiscussion', $modcontext)) {
        // Discussion subscription.
        if (\mod_forum\subscriptions::is_subscribable($forum)) {
            echo '<td class="discussionsubscription">';
            echo forum_get_discussion_subscription_icon($forum, $post->discussion);
            echo '</td>';
        }
    }
    echo "</tr>\n\n";
}

//.........这里部分代码省略.........
            print_error('invalidcoursemodule');
        }
        $modcontext = context_module::instance($cm->id);
    }
    if (!isset($rowcount)) {
        $rowcount = 0;
        $strmarkalldread = get_string('markalldread', 'forum');
    } else {
        $rowcount = ($rowcount + 1) % 2;
    }
    $post->subject = format_string($post->subject, true);
    echo "\n\n";
    echo '<tr class="discussion r' . $rowcount . '">';
    // Topic
    echo '<td class="topic starter">';
    echo '<a href="' . $CFG->wwwroot . '/mod/forum/discuss.php?d=' . $post->discussion . '">' . $post->subject . '</a>';
    echo "</td>\n";
    // Picture
    $postuser = new stdClass();
    $postuserfields = explode(',', user_picture::fields());
    $postuser = username_load_fields_from_object($postuser, $post, null, $postuserfields);
    $postuser->id = $post->userid;
    echo '<td class="picture">';
    echo $OUTPUT->user_picture($postuser, array('courseid' => $forum->course));
    echo "</td>\n";
    // User name
    $fullname = fullname($postuser, has_capability('moodle/site:viewfullnames', $modcontext));
    echo '<td class="author">';
    echo '<a href="' . $CFG->wwwroot . '/user/view.php?id=' . $post->userid . '&amp;course=' . $forum->course . '">' . $fullname . '</a>';
    echo "</td>\n";
    // Group picture
    if ($group !== -1) {
        // Groups are active - group is a group data object or NULL
        echo '<td class="picture group">';
        if (!empty($group->picture) and empty($group->hidepicture)) {
            print_group_picture($group, $forum->course, false, false, true);
        } else {
            if (isset($group->id)) {
                if ($canviewparticipants) {
                    echo '<a href="' . $CFG->wwwroot . '/user/index.php?id=' . $forum->course . '&amp;group=' . $group->id . '">' . $group->name . '</a>';
                } else {
                    echo $group->name;
                }
            }
        }
        echo "</td>\n";
    }
    if (has_capability('mod/forum:viewdiscussion', $modcontext)) {
        // Show the column with replies
        echo '<td class="replies">';
        echo '<a href="' . $CFG->wwwroot . '/mod/forum/discuss.php?d=' . $post->discussion . '">';
        echo $post->replies . '</a>';
        echo "</td>\n";
        if ($cantrack) {
            echo '<td class="replies">';
            if ($forumtracked) {
                if ($post->unread > 0) {
                    echo '<span class="unread">';
                    echo '<a href="' . $CFG->wwwroot . '/mod/forum/discuss.php?d=' . $post->discussion . '#unread">';
                    echo $post->unread;
                    echo '</a>';
                    echo '<a title="' . $strmarkalldread . '" href="' . $CFG->wwwroot . '/mod/forum/markposts.php?f=' . $forum->id . '&amp;d=' . $post->discussion . '&amp;mark=read&amp;returnpage=view.php">' . '<img src="' . $OUTPUT->pix_url('t/markasread') . '" class="iconsmall" alt="' . $strmarkalldread . '" /></a>';
                    echo '</span>';
                } else {
                    echo '<span class="read">';
                    echo $post->unread;
                    echo '</span>';
                }
            } else {
                echo '<span class="read">';
                echo '-';
                echo '</span>';
            }
            echo "</td>\n";
        }
    }
    echo '<td class="lastpost">';
    $usedate = empty($post->timemodified) ? $post->modified : $post->timemodified;
    // Just in case
    $parenturl = '';
    $usermodified = new stdClass();
    $usermodified->id = $post->usermodified;
    $usermodified = username_load_fields_from_object($usermodified, $post, 'um');
    // Show link to last poster and their post if user can see them.
    if ($canviewparticipants) {
        echo '<a href="' . $CFG->wwwroot . '/user/view.php?id=' . $post->usermodified . '&amp;course=' . $forum->course . '">' . fullname($usermodified) . '</a><br />';
        $parenturl = empty($post->lastpostid) ? '' : '&amp;parent=' . $post->lastpostid;
    }
    echo '<a href="' . $CFG->wwwroot . '/mod/forum/discuss.php?d=' . $post->discussion . $parenturl . '">' . userdate($usedate, $datestring) . '</a>';
    echo "</td>\n";
    if (has_capability('mod/forum:viewdiscussion', $modcontext)) {
        // Discussion subscription.
        if (\mod_forum\subscriptions::is_subscribable($forum)) {
            echo '<td class="discussionsubscription">';
            echo forum_get_discussion_subscription_icon($forum, $post->discussion);
            echo '</td>';
        }
    }
    echo "</tr>\n\n";
}

if ($node && $post->id != $discussion->firstpost) {
    $node->add(format_string($post->subject), $PAGE->url);
}
$PAGE->set_title("{$course->shortname}: " . format_string($discussion->name));
$PAGE->set_heading($course->fullname);
$PAGE->set_button($searchform);
$renderer = $PAGE->get_renderer('mod_forum');
echo $OUTPUT->header();
echo $OUTPUT->heading(format_string($forum->name), 2);
echo $OUTPUT->heading(format_string($discussion->name), 3, 'discussionname');
// is_guest should be used here as this also checks whether the user is a guest in the current course.
// Guests and visitors cannot subscribe - only enrolled users.
if (!is_guest($modcontext, $USER) && isloggedin() && has_capability('mod/forum:viewdiscussion', $modcontext)) {
    // Discussion subscription.
    if (\mod_forum\subscriptions::is_subscribable($forum)) {
        echo html_writer::div(forum_get_discussion_subscription_icon($forum, $post->discussion, null, true), 'discussionsubscription');
        echo forum_get_discussion_subscription_icon_preloaders();
    }
}
/// Check to see if groups are being used in this forum
/// If so, make sure the current person is allowed to see this discussion
/// Also, if we know they should be able to reply, then explicitly set $canreply for performance reasons
$canreply = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);
if (!$canreply and $forum->type !== 'news') {
    if (isguestuser() or !isloggedin()) {
        $canreply = true;
    }
    if (!is_enrolled($modcontext) and !is_viewing($modcontext)) {
        // allow guests and not-logged-in to see the link - they are prompted to log in after clicking the link
        // normal users with temporary guest access see this link too, they are asked to enrol instead
        $canreply = enrol_selfenrol_available($course->id);

$includetext = optional_param('includetext', false, PARAM_BOOL);
$forum = $DB->get_record('forum', array('id' => $forumid), '*', MUST_EXIST);
$course = $DB->get_record('course', array('id' => $forum->course), '*', MUST_EXIST);
$discussion = $DB->get_record('forum_discussions', array('id' => $discussionid, 'forum' => $forumid), '*', MUST_EXIST);
$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id, false, MUST_EXIST);
$context = context_module::instance($cm->id);
require_sesskey();
require_login($course, false, $cm);
require_capability('mod/forum:viewdiscussion', $context);
$return = new stdClass();
if (is_guest($context, $USER)) {
    // is_guest should be used here as this also checks whether the user is a guest in the current course.
    // Guests and visitors cannot subscribe - only enrolled users.
    throw new moodle_exception('noguestsubscribe', 'mod_forum');
}
if (!\mod_forum\subscriptions::is_subscribable($forum)) {
    // Nothing to do. We won't actually output any content here though.
    echo json_encode($return);
    die;
}
if (\mod_forum\subscriptions::is_subscribed($USER->id, $forum, $discussion->id, $cm)) {
    // The user is subscribed, unsubscribe them.
    \mod_forum\subscriptions::unsubscribe_user_from_discussion($USER->id, $discussion, $context);
} else {
    // The user is unsubscribed, subscribe them.
    \mod_forum\subscriptions::subscribe_user_to_discussion($USER->id, $discussion, $context);
}
// Now return the updated subscription icon.
$return->icon = forum_get_discussion_subscription_icon($forum, $discussion->id, null, $includetext);
echo json_encode($return);
die;

        $node->add(format_string($post->subject), $PAGE->url);
    }

    $PAGE->set_title("$course->shortname: ".format_string($discussion->name));
    $PAGE->set_heading($course->fullname);
    $PAGE->set_button($searchform);
    $renderer = $PAGE->get_renderer('mod_forum');

    echo $OUTPUT->header();

    $headingvalue = format_string($forum->name);
    if ((!isguestuser() && isloggedin()) && has_capability('mod/forum:viewdiscussion', $modcontext)) {
        // Discussion subscription.
        if (\mod_forum\subscriptions::is_subscribable($forum)) {
            $headingvalue .= ' ';
            $headingvalue .= html_writer::tag('span', forum_get_discussion_subscription_icon($forum, $post->discussion), array(
                'class' => 'discussionsubscription',
            ));
        }
    }
    echo $OUTPUT->heading($headingvalue, 2);


/// Check to see if groups are being used in this forum
/// If so, make sure the current person is allowed to see this discussion
/// Also, if we know they should be able to reply, then explicitly set $canreply for performance reasons

    $canreply = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);
    if (!$canreply and $forum->type !== 'news') {
        if (isguestuser() or !isloggedin()) {
            $canreply = true;

$PAGE->set_heading($course->fullname);
$PAGE->set_button($searchform);
$renderer = $PAGE->get_renderer('mod_forum');

echo $OUTPUT->header();

echo $OUTPUT->heading(format_string($forum->name), 2);
echo $OUTPUT->heading(format_string($discussion->name), 3, 'discussionname');

// is_guest should be used here as this also checks whether the user is a guest in the current course.
// Guests and visitors cannot subscribe - only enrolled users.
if ((!is_guest($modcontext, $USER) && isloggedin()) && has_capability('mod/forum:viewdiscussion', $modcontext)) {
    // Discussion subscription.
    if (\mod_forum\subscriptions::is_subscribable($forum)) {
        echo html_writer::div(
            forum_get_discussion_subscription_icon($forum, $post->discussion, null, true),
            'discussionsubscription'
        );
        echo forum_get_discussion_subscription_icon_preloaders();
    }
}


/// Check to see if groups are being used in this forum
/// If so, make sure the current person is allowed to see this discussion
/// Also, if we know they should be able to reply, then explicitly set $canreply for performance reasons

$canreply = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);
if (!$canreply and $forum->type !== 'news') {
    if (isguestuser() or !isloggedin()) {
        $canreply = true;

define('AJAX_SCRIPT', true);
require_once dirname(dirname(__DIR__)) . '/config.php';
require_once $CFG->dirroot . '/mod/forum/lib.php';
$forumid = required_param('forumid', PARAM_INT);
// The forum to subscribe or unsubscribe.
$discussionid = optional_param('discussionid', null, PARAM_INT);
// The discussionid to subscribe.
$sesskey = optional_param('sesskey', null, PARAM_RAW);
$forum = $DB->get_record('forum', array('id' => $forumid), '*', MUST_EXIST);
$course = $DB->get_record('course', array('id' => $forum->course), '*', MUST_EXIST);
$discussion = $DB->get_record('forum_discussions', array('id' => $discussionid), '*', MUST_EXIST);
$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id, false, MUST_EXIST);
$context = context_module::instance($cm->id);
require_login($course, false, $cm);
$return = new stdClass();
if (!\mod_forum\subscriptions::is_subscribable($forum)) {
    // Nothing to do. We won't actually output any content here though.
    echo json_encode($return);
    die;
}
if (\mod_forum\subscriptions::is_subscribed($USER->id, $forum, $discussion->id, $cm)) {
    // The user is subscribed, unsubscribe them.
    \mod_forum\subscriptions::unsubscribe_user_from_discussion($USER->id, $discussion, $context);
} else {
    // The user is unsubscribed, subscribe them.
    \mod_forum\subscriptions::subscribe_user_to_discussion($USER->id, $discussion, $context);
}
// Now return the updated subscription icon.
$return->icon = forum_get_discussion_subscription_icon($forum, $discussion->id);
echo json_encode($return);
die;