[ACCEPTED]-dependent dropdown yii2. How to do?-yii2

use the krajee extension for dependent drop 3 down

Details is here Krejee dependent dropdown for yii2

or follow following 2 instructions:

Install the extension via composer:

 $ php composer.phar require kartik-v/dependent-dropdown "dev-master"

In 1 your view :

  use kartik\widgets\DepDrop;

// Normal parent select
echo $form->field($model, 'cat')->dropDownList($catList, ['id' => 'cat-id']);

// Dependent Dropdown
echo $form->field($model, 'subcat')->widget(DepDrop::classname(), [
    'options' => ['id' => 'subcat-id'],
    'pluginOptions' => [
        'depends' => ['cat-id'],
        'placeholder' => 'Select...',
        'url' => Url::to(['/site/subcat'])
    ]
]);

// THE CONTROLLER

public function actionSubcat() {
$out = [];
if (isset($_POST['depdrop_parents'])) {
$parents = $_POST['depdrop_parents'];
if ($parents != null) {
$cat_id = $parents[0];
$out = self::getSubCatList($cat_id);
// the getSubCatList function will query the database based on the
// cat_id and return an array like below:
// [
// ['id'=>'<sub-cat-id-1>', 'name'=>'<sub-cat-name1>'],
// ['id'=>'<sub-cat_id_2>', 'name'=>'<sub-cat-name2>']
// ]
echo Json::encode(['output'=>$out, 'selected'=>'']);
return;
}
}
echo Json::encode(['output'=>'', 'selected'=>'']);
}

creating dependent dropdown in yii2 without 12 using any third party libraries is quite 11 as simple as yii1. you have to try following 10 code written below as per your requirements. use 9 gii to create models,views, controller for 8 respective tables.

suppose there r two table 7 like country, city as u written. then 6 write the following code into views file 5 for one controller(like country):

         <?php
                    use yii\helpers\ArrayHelper;
                    use yii\widgets\ActiveForm;
                    ?>
               <div>
            <?php
     $dataCountry=ArrayHelper::map(\app\models\Country::find()->
     asArray()->all(),'id', 'name');    
                  $form = ActiveForm::begin();
                echo $form->field($model, 'id')->dropDownList($dataCountry, 
                                     ['prompt'=>'-Choose a Name-',
                                         'class'=>'adjust',
                          'onchange'=>'
             $.post("'.Yii::$app->urlManager->createUrl('city/lists?id=').
           '"+$(this).val(),function( data ) 
                   {
                              $( "select#city" ).html( data );
                            });
                        ']); 

                $dataPost=ArrayHelper::map(\app\models\City::find()->
                 asArray()->all(), 'id', 'city');
              echo $form->field($model, 'id')
                    ->dropDownList(
                        $dataPost,   
                         ['id'=>'city',
                             'class'=>'adjust'
                             ]
                    );
                 ActiveForm::end(); 
               ?>
            </div>

and after 4 this in another controller for city write 3 following code as:

 <?php

namespace app\controllers;

class CityController extends \yii\web\Controller
{
        public function actionLists($id)
      {
         //echo "<pre>";print_r($id);die;
         $countPosts = \app\models\City::find()
         ->where(['country_id' => $id])
         ->count();

         $posts = \app\models\City::find()
         ->where(['country_id' => $id])
         ->orderBy('id DESC')
         ->all();

         if($countPosts>0){
         foreach($posts as $post){

         echo "<option value='".$post->id."'>".$post->city."</option>";
         }
         }
         else{
         echo "<option>-</option>";
         }

 }
}

then run into url it works!

edit: fixed 2 url construction. http requests will now 1 work.

You can do it without any widget manually:

make 5 your activeform as follows:

<?=  $form->field($model, 'nameofyourmodel')->dropDownList(
    ArrayHelper::map(\app\models\nameofyourmodel::find()->all(), 'id', 'name'),
    [
        'prompt'=>'smth',
        'onchange' => '
            $.post(
                "' . Url::toRoute('getoperations') . '", 
                {id: $(this).val()}, 
                function(res){
                    $("#requester").html(res);
                }
            );
        ',

    ]
); ?>

and here the 4 second form which receives the id from the 3 first model:

 <?= $form->field($model,'nameofyourmodel')->dropDownList(
    [],
    [
        'prompt' => 'smth',
        'id' => 'requester'
    ]
); ?>

and the last action is to make 2 a functionality in controller to match 2 1 ids and send them to your model:

public function actionGetoperations()
{
    if ($id = Yii::$app->request->post('id')) {
        $operationPosts = \app\models\firstmodel::find()
            ->where(['id' => $id])
            ->count();

        if ($operationPosts > 0) {
            $operations = \app\models\secondmodel::find()
                ->where(['firstmodelid' => $id])
                ->all();
            foreach ($operations as $operation)
                echo "<option value='" . $operation->firstmodelid. "'>" . $operation->name . "</option>";
        } else
            echo "<option>-</option>";

    }
}

The above code is not working properly. There 10 is an error in the line

$.post("'.Yii::$app->urlManager->createUrl('city/lists&id=').'"+$(this).val(),function( data ) 

console shows the 9 error : Not Found (#404): Unable to resolve 8 the request: subcategory/lists&id=54

is 7 there any solution for this my controller 6 looks like below

public function actionLists($id)
      {
         $posts = SubCategory::find()
         ->where(['category_id' => $id])
         ->orderBy('id DESC')
         ->all();

         if($posts){
         foreach($posts as $post){

         echo "<option value='".$post->id."'>".$post->name."</option>";
         }
         }
         else{
         echo "<option>-</option>";
         }

    }

when i remove the id from 5 the url and hard coded it in to controller 4 it works properly.

I have find a solution 3 for this please change your view as follows

 <?= $form->field($model, 'category_id')->dropDownList($data,['prompt'=>'-Choose a Category-',

                                                            'onchange'=>'
             $.get( "'.Url::toRoute('product/catlists').'", { id: $(this).val() } )
                            .done(function( data )
                   {
                              $( "select#product-sub_categoryid" ).html( data );
                            });
                        ']); ?> 

and 2 controller like this

public function actionCatlists($id)
    {
        $mymodel = new Product ();
        $size = $mymodel->modelGetCategory ( 'product_sub_category',$id );
        if($size){
            echo '<option value="">Choose Sub category</option>';
            foreach($size as $post){
                echo "<option value='".$post['id']."'>".$post['name']."</option>";
            }
        }
        else{
            echo '<option value="0">Not Specified</option>';
        }

    }

don't forget to include 1 this on your view

use yii\helpers\Url;