How to make a drop down list in yii2?

Question

How to make a dropdown in yii2 using an activeform and a model? Since all the methods has changed in yii2,how it is done in the new one?

Answer 1

It is like

<?php
use yii\helpers\ArrayHelper;
use backend\models\Standard;
?>

<?= Html::activeDropDownList($model, 's_id',
      ArrayHelper::map(Standard::find()->all(), 's_id', 'name')) ?>

ArrayHelper in Yii2 replaces the CHtml list data in Yii 1.1.[Please load array data from your controller]

EDIT

Load data from your controller.

Controller

$items = ArrayHelper::map(Standard::find()->all(), 's_id', 'name');
...
return $this->render('your_view',['model'=>$model, 'items'=>$items]);

In View

<?= Html::activeDropDownList($model, 's_id',$items) ?>

Answer 2

In ActiveForm just use:

<?=
    $form->field($model, 'state_id')
         ->dropDownList(['prompt' => '---- Select State ----'])
         ->label('State')
?>

Answer 3

Have a look this:

use yii\helpers\ArrayHelper; // load classes
use app\models\Course;
    .....
$dataList=ArrayHelper::map(Course::find()->asArray()->all(), 'id', 'name');
<?=$form->field($model, 'center_id')->dropDownList($dataList, 
         ['prompt'=>'-Choose a Course-']) ?>

Answer 4

If you made it to the bottom of the list. Save some php code and just bring everything back from the DB as you need like this:

 $items = Standard::find()->select(['name'])->indexBy('s_id')->column();

Answer 5

This is about generating data, and so is more properly done from the model. Imagine if you ever wanted to change the way data is displayed in the drop-down box, say add a surname or something. You'd have to find every drop-down box and change the arrayHelper. I use a function in my models to return the data for a dropdown, so I don't have to repeat code in views. It also has the advantage that I can specify filter here and have them apply to every dropdown created from this model;

/* Model Standard.php */

public function getDropdown(){
      return ArrayHelper::map(self::find()->all(), 's_id', 'name'));
}

You can use this in your view file like this;

echo $form->field($model, 'attribute')
        ->dropDownList(
            $model->dropDown
        );