fastadmin選擇下拉框兩級聯動

<div class="form-group">
        <label class="control-label col-xs-12 col-sm-2">發送者:</label>
        <div class="col-xs-12 col-sm-8">
            {:build_select('row[sender]', $senders, null, ['class'=>'form-control selectpicker sender', 'data-rule'=>'required'])}
        </div>
    </div>
    <div class="form-group">
        <label class="control-label col-xs-12 col-sm-2">{:__('External_userid')}:</label>
        <div class="col-xs-12 col-sm-8">
            <select  id="c-external_userid" class="form-control selectpicker" name="row[external_userid]">
                <option value="0" id="external_userid">請選擇</option>
            </select>
        </div>
    </div>

1.build_select是框架內置的函數，$senders為數據集

$('.sender').on('changed.bs.select', function() {//單擊時方法
        // console.log('agja');
        var ids = $(this).val();
        console.log($('.sender').selectpicker('val'));

        $.post('qywx.gmsglog/getFollowUser',
            {
                'userid':ids
            },
            function (data) {
                $('#c-external_userid').html("");
                for(var i in data){
                    $('#c-external_userid').append('<option value="'+data[i]+'">'+data[i]+'</option>')
                }
                $('select').selectpicker('refresh');
            }
        );
    });

1.當第一個select點擊選擇時候，通過jq監聽拿到數據，傳送給后台接口

public function getFollowUser()
    {
        $userid           = $this->request->post('userid');
        $external_userids = Db::name('qywx_resident_follow_user')->field('external_userid')->where('userid', $userid)->select()->toArray();
        $external_userids = array_column($external_userids, 'external_userid');
        $external_userids = array_combine($external_userids, $external_userids);

        return json($external_userids);

    }

1.通過json返回數據

思考：

　　1.定義兩個下拉選擇框，通過事件進行關聯，拿到第一個下拉框的id傳送給后台，拿到數據

　　2.每次點擊的時候需要清空之前的option

　　3.$('select').selectpicker('refresh');刷新一下select，重新加載append數據

　　4.select加multiple=""屬性為多選