下拉插件问题 [ 2.0 版本 ]

use kartik\select2\Select2;
用这个插件的做下拉
这是view
<?php $form = ActiveForm::begin(); ?>
<?php $form->field($model, 'id')->hiddenInput(['value'=>''])->label(false); ?>

<div class="col-md-3">
    <?= $form->field($model, 'supplier_code')->widget(Select2::classname(), [
        'options' => ['placeholder' => '请输入供应商 ...'],
        'pluginOptions' => [

            'language' => [
                'errorLoading' => new JsExpression("function () { return 'Waiting...'; }"),
            ],
            'ajax' => [
                'url' => $url,
                'dataType' => 'json',
                'data' => new JsExpression('function(params) { return {q:params.term}; }')
            ],
            'escapeMarkup' => new JsExpression('function (markup) { return markup; }'),
            'templateResult' => new JsExpression('function(res) { return res.text; }'),
           'templateSelection' => new JsExpression('function (res) { return res.text; }'),
        ],
    ])->label('供应商');
    ?>
</div>

<div class="form-group col-md-3" style="margin-top: 24px;">
    <?= Html::submitButton('提交', ['class' => 'btn btn-primary']) ?>
    <?= Html::resetButton('重置', ['class' => 'btn btn-default']) ?>
</div>

{
    \Yii::$app->response->format = \yii\web\Response::FORMAT_JSON;
    $out = ['results' => ['id' => '', 'text' => '']];
    if (!is_null($q)) {

        $data = Supplier::find()
            ->select('supplier_code as id,supplier_name AS text')
            ->andFilterWhere(['like', 'supplier_name', $q])
            ->distinct()
            ->limit(50)
            ->asArray()
            ->all();

        $out['results'] = array_values($data);
    }elseif ($id > 0) {
            $out['results'] = ['id' => $id, 'text' => Supplier::find($id)->supplier_name];
    }
    return $out;
}

发出来所诸君共解之，有遇到请晓于大家，谢谢