YII2 - How to get a field value from form for search

In Yii2, to get a field value from a form for searching, you can access the field's value through the $_GET or $_POST superglobal arrays, depending on the form's method (GET or POST). Yii2 provides a convenient way to handle form submissions and retrieve input values.

Assuming you have a form in your view file with a field named "searchField" and you want to use the value of this field for searching, follow these steps:

1. Create the Search Form: Create a search form in your view file using the ActiveForm widget or plain HTML.

   phpCopy code
   <?php
   use yii\helpers\Html;
   use yii\widgets\ActiveForm;
   
   $form = ActiveForm::begin(['method' => 'get']);
   ?>
   
   <?= $form->field($searchModel, 'searchField')->textInput() ?>
   
   <div class="form-group">
       <?= Html::submitButton('Search', ['class' => 'btn btn-primary']) ?>
   </div>
   
   <?php ActiveForm::end(); ?>
   

   In this example, the form uses the GET method, and the input field is named "searchField." The form will submit the search value as a query parameter in the URL.

2. Retrieve the Search Value in Controller: In your controller action, you can retrieve the value of the "searchField" from the $_GET superglobal array.

   phpCopy code
   namespace app\controllers;
   
   use Yii;
   use yii\web\Controller;
   
   class YourController extends Controller
   {
       public function actionSearch()
       {
           $searchModel = new YourSearchModel();
   
           // Get the search value from the request
           $searchValue = Yii::$app->request->get('searchField');
   
           // Use the search value for searching in your model or data provider
           $dataProvider = $searchModel->search($searchValue);
   
           return $this->render('search', [
               'searchModel' => $searchModel,
               'dataProvider' => $dataProvider,
           ]);
       }
   }
   

   In the example above, we use Yii::$app->request->get('searchField') to retrieve the value of "searchField" from the URL query parameters.

3. Use the Search Value for Filtering: You can now use the retrieved search value in your model or data provider to perform filtering or searching operations based on the user's input.

   For example, in your search model, you can define a method that takes the search value as a parameter and uses it to filter the data:

   phpCopy code
   namespace app\models;
   
   use yii\base\Model;
   use yii\data\ActiveDataProvider;
   
   class YourSearchModel extends Model
   {
       // ... other search model attributes and rules ...
   
       public function search($searchValue)
       {
           $query = YourModel::find();
   
           // Apply the search filter if the search value is not empty
           if (!empty($searchValue)) {
               $query->andWhere(['like', 'your_column', $searchValue]);
           }
   
           $dataProvider = new ActiveDataProvider([
               'query' => $query,
           ]);
   
           return $dataProvider;
       }
   }
   

   In this example, we use the $searchValue parameter to perform a "LIKE" search on the "your_column" attribute of the YourModel.

By following these steps, you can easily get the field value from a form for searching in Yii2 and use it to filter and search data based on the user's input.