/**
 * This function will empty a course of user data.
 * It will retain the activities and the structure of the course.
 * @param object $data an object containing all the settings including courseid (without magic quotes)
 * @return array status array of array component, item, error
 */
function reset_course_userdata($data)
{
    global $CFG, $USER;
    require_once $CFG->libdir . '/gradelib.php';
    require_once $CFG->dirroot . '/group/lib.php';
    $data->courseid = $data->id;
    $context = get_context_instance(CONTEXT_COURSE, $data->courseid);
    // calculate the time shift of dates
    if (!empty($data->reset_start_date)) {
        // time part of course startdate should be zero
        $data->timeshift = $data->reset_start_date - usergetmidnight($data->reset_start_date_old);
    } else {
        $data->timeshift = 0;
    }
    // result array: component, item, error
    $status = array();
    // start the resetting
    $componentstr = get_string('general');
    // move the course start time
    if (!empty($data->reset_start_date) and $data->timeshift) {
        // change course start data
        set_field('course', 'startdate', $data->reset_start_date, 'id', $data->courseid);
        // update all course and group events - do not move activity events
        $updatesql = "UPDATE {$CFG->prefix}event\n                         SET timestart = timestart + ({$data->timeshift})\n                       WHERE courseid={$data->courseid} AND instance=0";
        execute_sql($updatesql, false);
        $status[] = array('component' => $componentstr, 'item' => get_string('datechanged'), 'error' => false);
    }
    if (!empty($data->reset_logs)) {
        delete_records('log', 'course', $data->courseid);
        $status[] = array('component' => $componentstr, 'item' => get_string('deletelogs'), 'error' => false);
    }
    if (!empty($data->reset_events)) {
        delete_records('event', 'courseid', $data->courseid);
        $status[] = array('component' => $componentstr, 'item' => get_string('deleteevents', 'calendar'), 'error' => false);
    }
    if (!empty($data->reset_notes)) {
        require_once $CFG->dirroot . '/notes/lib.php';
        note_delete_all($data->courseid);
        $status[] = array('component' => $componentstr, 'item' => get_string('deletenotes', 'notes'), 'error' => false);
    }
    $componentstr = get_string('roles');
    if (!empty($data->reset_roles_overrides)) {
        $children = get_child_contexts($context);
        foreach ($children as $child) {
            delete_records('role_capabilities', 'contextid', $child->id);
        }
        delete_records('role_capabilities', 'contextid', $context->id);
        //force refresh for logged in users
        mark_context_dirty($context->path);
        $status[] = array('component' => $componentstr, 'item' => get_string('deletecourseoverrides', 'role'), 'error' => false);
    }
    if (!empty($data->reset_roles_local)) {
        $children = get_child_contexts($context);
        foreach ($children as $child) {
            role_unassign(0, 0, 0, $child->id);
        }
        //force refresh for logged in users
        mark_context_dirty($context->path);
        $status[] = array('component' => $componentstr, 'item' => get_string('deletelocalroles', 'role'), 'error' => false);
    }
    // First unenrol users - this cleans some of related user data too, such as forum subscriptions, tracking, etc.
    $data->unenrolled = array();
    if (!empty($data->reset_roles)) {
        foreach ($data->reset_roles as $roleid) {
            if ($users = get_role_users($roleid, $context, false, 'u.id', 'u.id ASC')) {
                foreach ($users as $user) {
                    role_unassign($roleid, $user->id, 0, $context->id);
                    if (!has_capability('moodle/course:view', $context, $user->id)) {
                        $data->unenrolled[$user->id] = $user->id;
                    }
                }
            }
        }
    }
    if (!empty($data->unenrolled)) {
        $status[] = array('component' => $componentstr, 'item' => get_string('unenrol') . ' (' . count($data->unenrolled) . ')', 'error' => false);
    }
    $componentstr = get_string('groups');
    // remove all group members
    if (!empty($data->reset_groups_members)) {
        groups_delete_group_members($data->courseid);
        $status[] = array('component' => $componentstr, 'item' => get_string('removegroupsmembers', 'group'), 'error' => false);
    }
    // remove all groups
    if (!empty($data->reset_groups_remove)) {
        groups_delete_groups($data->courseid, false);
        $status[] = array('component' => $componentstr, 'item' => get_string('deleteallgroups', 'group'), 'error' => false);
    }
    // remove all grouping members
    if (!empty($data->reset_groupings_members)) {
        groups_delete_groupings_groups($data->courseid, false);
        $status[] = array('component' => $componentstr, 'item' => get_string('removegroupingsmembers', 'group'), 'error' => false);
    }
    // remove all groupings
//.........这里部分代码省略.........

//.........这里部分代码省略.........
        $userid = reset($testusers);
        $usercontext = context_user::instance($userid);
        $this->assertSame($usercontext->get_parent_context(), $systemcontext);
        $this->assertSame($usercontext->get_parent_contexts(), array($systemcontext->id=>$systemcontext));
        $this->assertSame($usercontext->get_parent_contexts(true), array($usercontext->id=>$usercontext, $systemcontext->id=>$systemcontext));

        $this->assertSame($systemcontext->get_parent_contexts(), array());
        $this->assertSame($systemcontext->get_parent_contexts(true), array($systemcontext->id=>$systemcontext));
        $this->assertSame($systemcontext->get_parent_context_ids(), array());
        $this->assertSame($systemcontext->get_parent_context_ids(true), array($systemcontext->id));

        $this->assertSame($frontpagecontext->get_parent_context(), $systemcontext);
        $this->assertSame($frontpagecontext->get_parent_contexts(), array($systemcontext->id=>$systemcontext));
        $this->assertSame($frontpagecontext->get_parent_contexts(true), array($frontpagecontext->id=>$frontpagecontext, $systemcontext->id=>$systemcontext));
        $this->assertSame($frontpagecontext->get_parent_context_ids(), array($systemcontext->id));
        $this->assertEquals($frontpagecontext->get_parent_context_ids(true), array($frontpagecontext->id, $systemcontext->id));

        $this->assertSame($systemcontext->get_parent_context(), false);
        $frontpagecontext = context_course::instance($SITE->id);
        $parent = $systemcontext;
        foreach ($testcategories as $catid) {
            $catcontext = context_coursecat::instance($catid);
            $this->assertSame($catcontext->get_parent_context(), $parent);
            $parent = $catcontext;
        }
        $this->assertSame($frontpagepagecontext->get_parent_context(), $frontpagecontext);
        $this->assertSame($frontpageblockcontext->get_parent_context(), $frontpagecontext);
        $this->assertSame($frontpagepageblockcontext->get_parent_context(), $frontpagepagecontext);


        // ====== $context->get_child_contexts() ================================

        $CFG->debug = 0;
        $children = $systemcontext->get_child_contexts();
        $CFG->debug = DEBUG_DEVELOPER;
        $this->assertEquals(count($children)+1, $DB->count_records('context'));

        $context = context_coursecat::instance($testcategories[3]);
        $children = $context->get_child_contexts();
        $countcats    = 0;
        $countcourses = 0;
        $countblocks  = 0;
        foreach ($children as $child) {
            if ($child->contextlevel == CONTEXT_COURSECAT) {
                $countcats++;
            }
            if ($child->contextlevel == CONTEXT_COURSE) {
                $countcourses++;
            }
            if ($child->contextlevel == CONTEXT_BLOCK) {
                $countblocks++;
            }
        }
        $this->assertEquals(count($children), 8);
        $this->assertEquals($countcats, 1);
        $this->assertEquals($countcourses, 6);
        $this->assertEquals($countblocks, 1);

        $context = context_course::instance($testcourses[2]);
        $children = $context->get_child_contexts();
        $this->assertEquals(count($children), 7); // depends on number of default blocks

        $context = context_module::instance($testpages[3]);
        $children = $context->get_child_contexts();
        $this->assertEquals(count($children), 1);

function get_role_context_caps($roleid, $context)
{
    global $DB;
    //this is really slow!!!! - do not use above course context level!
    $result = array();
    $result[$context->id] = array();
    // first emulate the parent context capabilities merging into context
    $searchcontexts = array_reverse(get_parent_contexts($context));
    array_push($searchcontexts, $context->id);
    foreach ($searchcontexts as $cid) {
        if ($capabilities = $DB->get_records('role_capabilities', array('roleid' => $roleid, 'contextid' => $cid))) {
            foreach ($capabilities as $cap) {
                if (!array_key_exists($cap->capability, $result[$context->id])) {
                    $result[$context->id][$cap->capability] = 0;
                }
                $result[$context->id][$cap->capability] += $cap->permission;
            }
        }
    }
    // now go through the contexts bellow given context
    $searchcontexts = array_keys(get_child_contexts($context));
    foreach ($searchcontexts as $cid) {
        if ($capabilities = $DB->get_records('role_capabilities', array('roleid' => $roleid, 'contextid' => $cid))) {
            foreach ($capabilities as $cap) {
                if (!array_key_exists($cap->contextid, $result)) {
                    $result[$cap->contextid] = array();
                }
                $result[$cap->contextid][$cap->capability] = $cap->permission;
            }
        }
    }
    return $result;
}

/**
 * This function will empty a course of user data.
 * It will retain the activities and the structure of the course.
 *
 * @param object $data an object containing all the settings including courseid (without magic quotes)
 * @return array status array of array component, item, error
 */
function reset_course_userdata($data)
{
    global $CFG, $USER, $DB;
    require_once $CFG->libdir . '/gradelib.php';
    require_once $CFG->libdir . '/completionlib.php';
    require_once $CFG->dirroot . '/group/lib.php';
    $data->courseid = $data->id;
    $context = get_context_instance(CONTEXT_COURSE, $data->courseid);
    // calculate the time shift of dates
    if (!empty($data->reset_start_date)) {
        // time part of course startdate should be zero
        $data->timeshift = $data->reset_start_date - usergetmidnight($data->reset_start_date_old);
    } else {
        $data->timeshift = 0;
    }
    // result array: component, item, error
    $status = array();
    // start the resetting
    $componentstr = get_string('general');
    // move the course start time
    if (!empty($data->reset_start_date) and $data->timeshift) {
        // change course start data
        $DB->set_field('course', 'startdate', $data->reset_start_date, array('id' => $data->courseid));
        // update all course and group events - do not move activity events
        $updatesql = "UPDATE {event}\n                         SET timestart = timestart + ?\n                       WHERE courseid=? AND instance=0";
        $DB->execute($updatesql, array($data->timeshift, $data->courseid));
        $status[] = array('component' => $componentstr, 'item' => get_string('datechanged'), 'error' => false);
    }
    if (!empty($data->reset_logs)) {
        $DB->delete_records('log', array('course' => $data->courseid));
        $status[] = array('component' => $componentstr, 'item' => get_string('deletelogs'), 'error' => false);
    }
    if (!empty($data->reset_events)) {
        $DB->delete_records('event', array('courseid' => $data->courseid));
        $status[] = array('component' => $componentstr, 'item' => get_string('deleteevents', 'calendar'), 'error' => false);
    }
    if (!empty($data->reset_notes)) {
        require_once $CFG->dirroot . '/notes/lib.php';
        note_delete_all($data->courseid);
        $status[] = array('component' => $componentstr, 'item' => get_string('deletenotes', 'notes'), 'error' => false);
    }
    if (!empty($data->delete_blog_associations)) {
        require_once $CFG->dirroot . '/blog/lib.php';
        blog_remove_associations_for_course($data->courseid);
        $status[] = array('component' => $componentstr, 'item' => get_string('deleteblogassociations', 'blog'), 'error' => false);
    }
    if (!empty($data->reset_course_completion)) {
        // Delete course completion information
        $course = $DB->get_record('course', array('id' => $data->courseid));
        $cc = new completion_info($course);
        $cc->delete_course_completion_data();
        $status[] = array('component' => $componentstr, 'item' => get_string('deletecoursecompletiondata', 'completion'), 'error' => false);
    }
    $componentstr = get_string('roles');
    if (!empty($data->reset_roles_overrides)) {
        $children = get_child_contexts($context);
        foreach ($children as $child) {
            $DB->delete_records('role_capabilities', array('contextid' => $child->id));
        }
        $DB->delete_records('role_capabilities', array('contextid' => $context->id));
        //force refresh for logged in users
        mark_context_dirty($context->path);
        $status[] = array('component' => $componentstr, 'item' => get_string('deletecourseoverrides', 'role'), 'error' => false);
    }
    if (!empty($data->reset_roles_local)) {
        $children = get_child_contexts($context);
        foreach ($children as $child) {
            role_unassign_all(array('contextid' => $child->id));
        }
        //force refresh for logged in users
        mark_context_dirty($context->path);
        $status[] = array('component' => $componentstr, 'item' => get_string('deletelocalroles', 'role'), 'error' => false);
    }
    // First unenrol users - this cleans some of related user data too, such as forum subscriptions, tracking, etc.
    $data->unenrolled = array();
    if (!empty($data->unenrol_users)) {
        $plugins = enrol_get_plugins(true);
        $instances = enrol_get_instances($data->courseid, true);
        foreach ($instances as $key => $instance) {
            if (!isset($plugins[$instance->enrol])) {
                unset($instances[$key]);
                continue;
            }
            if (!$plugins[$instance->enrol]->allow_unenrol($instance)) {
                unset($instances[$key]);
            }
        }
        $sqlempty = $DB->sql_empty();
        foreach ($data->unenrol_users as $withroleid) {
            $sql = "SELECT DISTINCT ue.userid, ue.enrolid\n                      FROM {user_enrolments} ue\n                      JOIN {enrol} e ON (e.id = ue.enrolid AND e.courseid = :courseid)\n                      JOIN {context} c ON (c.contextlevel = :courselevel AND c.instanceid = e.courseid)\n                      JOIN {role_assignments} ra ON (ra.contextid = c.id AND ra.roleid = :roleid AND ra.userid = ue.userid)";
            $params = array('courseid' => $data->courseid, 'roleid' => $withroleid, 'courselevel' => CONTEXT_COURSE);
            $rs = $DB->get_recordset_sql($sql, $params);
            foreach ($rs as $ue) {
//.........这里部分代码省略.........

/**
 * Removes multiple role assignments, parameters may contain:
 *   'roleid', 'userid', 'contextid', 'component', 'enrolid'.
 *
 * @param array $params role assignment parameters
 * @param bool $subcontexts unassign in subcontexts too
 * @param bool $includmanual include manual role assignments too
 * @return void
 */
function role_unassign_all(array $params, $subcontexts = false, $includemanual = false)
{
    global $USER, $CFG, $DB;
    if (!$params) {
        throw new coding_exception('Missing parameters in role_unsassign_all() call');
    }
    $allowed = array('roleid', 'userid', 'contextid', 'component', 'itemid');
    foreach ($params as $key => $value) {
        if (!in_array($key, $allowed)) {
            throw new coding_exception('Unknown role_unsassign_all() parameter key', 'key:' . $key);
        }
    }
    if (isset($params['component']) and $params['component'] !== '' and strpos($params['component'], '_') === false) {
        throw new coding_exception('Invalid component paramter in role_unsassign_all() call', 'component:' . $params['component']);
    }
    if ($includemanual) {
        if (!isset($params['component']) or $params['component'] === '') {
            throw new coding_exception('include manual parameter requires component parameter in role_unsassign_all() call');
        }
    }
    if ($subcontexts) {
        if (empty($params['contextid'])) {
            throw new coding_exception('subcontexts paramtere requires component parameter in role_unsassign_all() call');
        }
    }
    $ras = $DB->get_records('role_assignments', $params);
    foreach ($ras as $ra) {
        $DB->delete_records('role_assignments', array('id' => $ra->id));
        if ($context = get_context_instance_by_id($ra->contextid)) {
            // this is a bit expensive but necessary
            mark_context_dirty($context->path);
            /// If the user is the current user, then do full reload of capabilities too.
            if (!empty($USER->id) && $USER->id == $ra->userid) {
                load_all_capabilities();
            }
        }
        events_trigger('role_unassigned', $ra);
    }
    unset($ras);
    // process subcontexts
    if ($subcontexts and $context = get_context_instance_by_id($params['contextid'])) {
        $contexts = get_child_contexts($context);
        $mparams = $params;
        foreach ($contexts as $context) {
            $mparams['contextid'] = $context->id;
            $ras = $DB->get_records('role_assignments', $mparams);
            foreach ($ras as $ra) {
                $DB->delete_records('role_assignments', array('id' => $ra->id));
                // this is a bit expensive but necessary
                mark_context_dirty($context->path);
                /// If the user is the current user, then do full reload of capabilities too.
                if (!empty($USER->id) && $USER->id == $ra->userid) {
                    load_all_capabilities();
                }
                events_trigger('role_unassigned', $ra);
            }
        }
    }
    // do this once more for all manual role assignments
    if ($includemanual) {
        $params['component'] = '';
        role_unassign_all($params, $subcontexts, false);
    }
}

 /**
  * Delete page_comments in whole course, used by course reset
  *
  * @param stdClass $context course context
  */
 public static function reset_course_page_comments($context) {
     global $DB;
     $contexts = array();
     $contexts[] = $context->id;
     $children = get_child_contexts($context);
     foreach ($children as $c) {
         $contexts[] = $c->id;
     }
     list($ids, $params) = $DB->get_in_or_equal($contexts);
     $DB->delete_records_select('comments', "commentarea='page_comments' AND contextid $ids", $params);
 }

 function init_full()
 {
     global $COURSE;
     if ($this->full_init_done) {
         return;
     }
     if (empty($this->id)) {
         $this->id = 0;
         // avoid db errors
     }
     if ($this->id == $COURSE->id) {
         $this->courserecord = $COURSE;
     } else {
         $this->courserecord = get_record('course', 'id', $this->id);
     }
     if (empty($this->courserecord) && !defined('ADMIN_STICKYBLOCKS')) {
         error('Cannot fully initialize page: invalid course id ' . $this->id);
     }
     $this->context = get_context_instance(CONTEXT_COURSE, $this->id);
     // Preload - ensures that the context cache is populated
     // in one DB query...
     $this->childcontexts = get_child_contexts($this->context);
     // Mark we're done
     $this->full_init_done = true;
 }

//.........这里部分代码省略.........
     } catch (Exception $e) {
         $this->assertTrue(true);
     }
     $this->assertIdentical($frontpagecontext->get_course_context(true), $frontpagecontext);
     $this->assertIdentical($frontpagepagecontext->get_course_context(true), $frontpagecontext);
     $this->assertIdentical($frontpagepageblockcontext->get_course_context(true), $frontpagecontext);
     // ======= $context->get_parent_context(), $context->get_parent_contexts(), $context->get_parent_context_ids() =======
     $userid = reset($testusers);
     $usercontext = context_user::instance($userid);
     $this->assertIdentical($usercontext->get_parent_context(), $systemcontext);
     $this->assertIdentical($usercontext->get_parent_contexts(), array($systemcontext->id => $systemcontext));
     $this->assertIdentical($usercontext->get_parent_contexts(true), array($usercontext->id => $usercontext, $systemcontext->id => $systemcontext));
     $this->assertIdentical($systemcontext->get_parent_contexts(), array());
     $this->assertIdentical($systemcontext->get_parent_contexts(true), array($systemcontext->id => $systemcontext));
     $this->assertIdentical($systemcontext->get_parent_context_ids(), array());
     $this->assertIdentical($systemcontext->get_parent_context_ids(true), array($systemcontext->id));
     $this->assertIdentical($frontpagecontext->get_parent_context(), $systemcontext);
     $this->assertIdentical($frontpagecontext->get_parent_contexts(), array($systemcontext->id => $systemcontext));
     $this->assertIdentical($frontpagecontext->get_parent_contexts(true), array($frontpagecontext->id => $frontpagecontext, $systemcontext->id => $systemcontext));
     $this->assertIdentical($frontpagecontext->get_parent_context_ids(), array($systemcontext->id));
     $this->assertEqual($frontpagecontext->get_parent_context_ids(true), array($frontpagecontext->id, $systemcontext->id));
     $this->assertIdentical($systemcontext->get_parent_context(), false);
     $frontpagecontext = context_course::instance($SITE->id);
     $parent = $systemcontext;
     foreach ($testcategories as $catid) {
         $catcontext = context_coursecat::instance($catid);
         $this->assertIdentical($catcontext->get_parent_context(), $parent);
         $parent = $catcontext;
     }
     $this->assertIdentical($frontpagepagecontext->get_parent_context(), $frontpagecontext);
     $this->assertIdentical($frontpageblockcontext->get_parent_context(), $frontpagecontext);
     $this->assertIdentical($frontpagepageblockcontext->get_parent_context(), $frontpagepagecontext);
     // ====== $context->get_child_contexts() ================================
     $children = $systemcontext->get_child_contexts();
     $this->assertEqual(count($children) + 1, $DB->count_records('context'));
     $context = context_coursecat::instance($testcategories[3]);
     $children = $context->get_child_contexts();
     $countcats = 0;
     $countcourses = 0;
     $countblocks = 0;
     foreach ($children as $child) {
         if ($child->contextlevel == CONTEXT_COURSECAT) {
             $countcats++;
         }
         if ($child->contextlevel == CONTEXT_COURSE) {
             $countcourses++;
         }
         if ($child->contextlevel == CONTEXT_BLOCK) {
             $countblocks++;
         }
     }
     $this->assertEqual(count($children), 8);
     $this->assertEqual($countcats, 1);
     $this->assertEqual($countcourses, 6);
     $this->assertEqual($countblocks, 1);
     $context = context_course::instance($testcourses[2]);
     $children = $context->get_child_contexts();
     $this->assertEqual(count($children), 3);
     $context = context_module::instance($testpages[3]);
     $children = $context->get_child_contexts();
     $this->assertEqual(count($children), 1);
     $context = context_block::instance($testblocks[1]);
     $children = $context->get_child_contexts();
     $this->assertEqual(count($children), 0);
     unset($children);
     unset($countcats);

/**
 * Recursive function which, given a context, find all its children context ids.
 * @param object $context.
 * @return array of children context ids.
 */
function get_child_contexts($context)
{
    global $CFG;
    $children = array();
    switch ($context->contextlevel) {
        case CONTEXT_BLOCK:
            // No children.
            return array();
            break;
        case CONTEXT_MODULE:
            // No children.
            return array();
            break;
        case CONTEXT_GROUP:
            // No children.
            return array();
            break;
        case CONTEXT_COURSE:
            // Find all block instances for the course.
            $page = new page_course();
            $page->id = $context->instanceid;
            $page->type = 'course-view';
            if ($blocks = blocks_get_by_page_pinned($page)) {
                foreach ($blocks['l'] as $leftblock) {
                    if ($child = get_context_instance(CONTEXT_BLOCK, $leftblock->id)) {
                        array_push($children, $child->id);
                    }
                }
                foreach ($blocks['r'] as $rightblock) {
                    if ($child = get_context_instance(CONTEXT_BLOCK, $rightblock->id)) {
                        array_push($children, $child->id);
                    }
                }
            }
            // Find all module instances for the course.
            if ($modules = get_records('course_modules', 'course', $context->instanceid)) {
                foreach ($modules as $module) {
                    if ($child = get_context_instance(CONTEXT_MODULE, $module->id)) {
                        array_push($children, $child->id);
                    }
                }
            }
            // Find all group instances for the course.
            if ($groupids = groups_get_groups($context->instanceid)) {
                foreach ($groupids as $groupid) {
                    if ($child = get_context_instance(CONTEXT_GROUP, $groupid)) {
                        array_push($children, $child->id);
                    }
                }
            }
            return $children;
            break;
        case CONTEXT_COURSECAT:
            // We need to get the contexts for:
            //   1) The subcategories of the given category
            //   2) The courses in the given category and all its subcategories
            //   3) All the child contexts for these courses
            $categories = get_all_subcategories($context->instanceid);
            // Add the contexts for all the subcategories.
            foreach ($categories as $catid) {
                if ($catci = get_context_instance(CONTEXT_COURSECAT, $catid)) {
                    array_push($children, $catci->id);
                }
            }
            // Add the parent category as well so we can find the contexts
            // for its courses.
            array_unshift($categories, $context->instanceid);
            foreach ($categories as $catid) {
                // Find all courses for the category.
                if ($courses = get_records('course', 'category', $catid)) {
                    foreach ($courses as $course) {
                        if ($courseci = get_context_instance(CONTEXT_COURSE, $course->id)) {
                            array_push($children, $courseci->id);
                            $children = array_merge($children, get_child_contexts($courseci));
                        }
                    }
                }
            }
            return $children;
            break;
        case CONTEXT_USER:
            // No children.
            return array();
            break;
        case CONTEXT_PERSONAL:
            // No children.
            return array();
            break;
        case CONTEXT_SYSTEM:
            // Just get all the contexts except for CONTEXT_SYSTEM level.
            $sql = 'SELECT c.id ' . 'FROM ' . $CFG->prefix . 'context AS c ' . 'WHERE contextlevel != ' . CONTEXT_SYSTEM;
            $contexts = get_records_sql($sql);
            foreach ($contexts as $cid) {
                array_push($children, $cid->id);
            }
//.........这里部分代码省略.........