backend/views/specialization/_form.php

<?php
use yii\helpers\Html;
use yii\widgets\ActiveForm;
use yii\helpers\ArrayHelper;
/* @var $this yii\web\View */
/* @var $model common\models\Specialization */
/* @var $form yii\widgets\ActiveForm */
?>
<div class="specialization-form">
    <?php $form = ActiveForm::begin(); ?>
    <?= $form->field($model, 'specialization_pid')->dropDownList(ArrayHelper::map($model->find()->all(), 'specialization_id', 'specialization_name'), ['prompt' => 'Выберие родителя']) ?>
    <?= $form->field($model, 'specialization_name')->textInput(['maxlength' => true]) ?>
    <?= \common\widgets\ImageUploader::widget([
        'model'=> $model,
        'field'=>'img',
        'width'=>240,
        'height'=>160,
        'multi'=>false,
        'gallery' =>$model->img,
        'name' => 'Загрузить картинку'
    ]); ?>
    <div class="form-group">
        <?= Html::submitButton($model->isNewRecord ? 'Create' : 'Update', ['class' => $model->isNewRecord ? 'btn btn-success' : 'btn btn-primary']) ?>
    </div>
    <?php ActiveForm::end(); ?>
</div>