backend/views/bg/_form.php

<?php
use yii\helpers\Html;
use yii\widgets\ActiveForm;
/* @var $this yii\web\View */
/* @var $model common\models\Bg */
/* @var $form yii\widgets\ActiveForm */
?>
<div class="bg-form">
    <?php $form = ActiveForm::begin([
        'enableClientValidation' => false,
        'options' => ['enctype' => 'multipart/form-data']
    ]); ?>
    <?= $form->field($model, 'title')->textInput(['maxlength' => true]) ?>
    <?= $form->field($model, 'url')->textInput(['maxlength' => true]) ?>
    <?= $form->field($model, 'image')->widget(\kartik\file\FileInput::classname(), [
        'language' => 'ru',
        'options' => [
            'accept' => 'image/*',
            'multiple' => false,
        ],
        'pluginOptions' => [
            'allowedFileExtensions' => ['jpg', 'gif', 'png'],
            'initialPreview' => !empty($model->imageUrl) ? \common\components\artboximage\ArtboxImageHelper::getImage($model->imageUrl, 'list') : '',
            'overwriteInitial' => true,
            'showRemove' => false,
            'showUpload' => false,
            'previewFileType' => 'image',
        ],
    ]); ?>
    <div class="form-group">
        <?= Html::submitButton($model->isNewRecord ? 'Create' : 'Update', ['class' => $model->isNewRecord ? 'btn btn-success' : 'btn btn-primary']) ?>
    </div>
    <?php ActiveForm::end(); ?>
</div>