if (isset($_REQUEST['form'])) {

    //这里面是点击创建主机组的页面展示

}else{

    //从这里开始分析

}

    $sortfield = getPageSortField('name');    //获取排序的字段依据

    $sortorder =  getPageSortOrder();    //升序降序

    $data = array(

        'config' => $config,     //获取配置

        'displayNodes' => is_array(get_current_nodeid()) //获取展示的节点，字面意义，具体是啥不知道，暂时不深究

    );

    $groups = API::HostGroup()->get(array(

        'editable' => true,      //将权限设置为PERM_READ_WRITE，否则为PERM_READ

        'output' => array('groupid'),    //在select 后面增加字段'groupid',注释掉这句，发现获得的数据是一样的，应该默认是有groupid字段的。applyQueryOutputOptions()

        'sortfield' => $sortfield,      //在order by 后面增加字段$sortfield，此处为'name'，会自动加表的别名，g.name。applyQuerySortOptions()->applyQuerySortField()

        'limit' => $config['search_limit'] + 1    //默认是1000,不知道+1是为什么，然后在zabbix生产sql的方法createSelectQueryFromParts()发现并没有对'limit'做任何操作，感觉这里写不写无所谓

    ));

$data['paging'] = getPagingLine($groups, array('groupid'));

    // get hosts and templates count

    $data['groupCounts'] = API::HostGroup()->get(array(

        'groupids' => zbx_objectValues($groups, 'groupid'),  //在sql语句where后面添加(g.groupid BETWEEN '4' AND '17' OR g.groupid IN ('1','2')

        'selectHosts' => API_OUTPUT_COUNT,  //API::HostGroup()->get()->addRelatedObjects()->API::Host()->get()SELECT DISTINCT COUNT(DISTINCT h.hostid) AS rowscount,hg.groupid FROM hosts h,hosts_groups hg WHERE h.flags IN (0,4) AND (hg.groupid BETWEEN '4' AND '17' OR hg.groupid IN ('1','2')) AND hg.hostid=h.hostid AND h.status IN (0,1) GROUP BY hg.groupid

        'selectTemplates' => API_OUTPUT_COUNT,  //API::HostGroup()->get()->addRelatedObjects()->API::Host()->get()

        'nopermissions' => true  //

    ));

$data['groupCounts'] = zbx_toHash($data['groupCounts'], 'groupid');

	$data['groups'] = API::HostGroup()->get(array(

		'groupids' => zbx_objectValues($groups, 'groupid'),

		'selectHosts' => array('hostid', 'name', 'status'),

		'selectTemplates' => array('hostid', 'name', 'status'),

		'selectGroupDiscovery' => array('ts_delete'),

		'selectDiscoveryRule' => array('itemid', 'name'),

		'output' => API_OUTPUT_EXTEND,

		'limitSelects' => $config['max_in_table'] + 1

	));

order_result($data['groups'], $sortfield, $sortorder);