创建一个自定义输入小部件

创建一个自定义输入小部件

Yii有一套非常好的表单小部件，但和其它框架一样，Yii并不能涵盖所有。在本小节中，我们将会学习如何创建自己的输入小部件。这里我们将创建一个范围输入小部件。

准备

按照官方指南http://www.yiiframework.com/doc-2.0/guide-start-installation.html的描述，使用Composer包管理器创建一个新的应用。

如何做…

创建一个小组件文件@app/components/RangeInputWidget.php：

<?php
namespace app\components;
use yii\base\Exception;
use yii\base\Model;
use yii\base\Widget;
use yii\helpers\Html;
class RangeInputWidget extends Widget
{
    public $model;
    public $attributeFrom;
    public $attributeTo;
    public $htmlOptions = [];
    protected function hasModel()
    {
        return $this->model instanceof Model&&
        $this->attributeFrom !== null&& $this->attributeTo !== null;
    }
    public function run()
    {
        if (!$this->hasModel()) {
            throw new Exception('Model must be set');
        }
        return Html::activeTextInput($this->model, $this->attributeFrom, $this->htmlOptions) 
            .' &rarr; ' 
            .Html::activeTextInput($this->model, $this->attributeTo, $this->htmlOptions);
    }
}

创建一个控制器文件@app/controllers/RangeController.php：

<?php
namespace app\controllers;
use Yii;
use yii\web\Controller;
use app\models\RangeForm;
class RangeController extends Controller
{
    public function actionIndex()
    {
        $model = new RangeForm();
        if ($model->load(Yii::$app->request->post()) &&
            $model->validate()) {
            Yii::$app->session->setFlash('rangeFormSubmitted',
                'The form was successfully processed!'
            );
        }
        return $this->render('index', array(
            'model' => $model,
        ));
    }
}

创建一个表单文件@app/models/RangeForm.php：

<?php
namespace app\models;
use yii\base\Model;
class RangeForm extends Model
{
    public $from;
    public $to;
    public function rules()
    {
        return [
            [['from', 'to'], 'number', 'integerOnly' => true],
            ['from', 'compare', 'compareAttribute' => 'to',
                'operator' => '<='],
        ];
    }
}

创建一个视图文件@app/views/range/index.php：

<?php
use yii\helpers\Html;
use yii\bootstrap\ActiveForm;
use app\components\RangeInputWidget;
?>
<h1>Range form</h1>
<?php if (Yii::$app->session->hasFlash('rangeFormSubmitted')):
    ?>
    <div class="alert alert-success">
        <?= Yii::$app->session->getFlash('rangeFormSubmitted');
        ?>
    </div>
<?php endif?>
<?= Html::errorSummary($model, ['class'=>'alert alert-danger'])?>
<?php $form = ActiveForm::begin([
    'options' => [
        'class' => 'form-inline'
    ]
]); ?>
<div class="form-group">
    <?= RangeInputWidget::widget([
        'model' => $model,
        'attributeFrom' => 'from',
        'attributeTo' => 'to',
        'htmlOptions' => [
            'class' =>'form-control'
        ]
    ]) ?>
</div>
<?= Html::submitButton('Submit', ['class' => 'btn btn-primary', 'name' => 'contact-button']) ?>
<?php ActiveForm::end(); ?>