Yii 2.0 Select Pre-selected values from Database - yii

Question

I have been trying to fix an issue but to no avail but i am sure i will find a solution here. I am using Kartik 2.0 Select extension to do a multiple select. Fine, all working when inserting into the database but i am unable to retrieve the saved records to be displayed as selected back in the select field.
//I have included the kartik widgets already
use kartik\widgets\Select2;
<label>Desired Specialization(s)</label>
<?= $form->field($spec, 'id')->label(false)->widget(Select2::classname(), [
'data' => $model->getAllSpecializations(),
'options' => ['placeholder' => 'You can choose more than one specialization ...'],
'pluginOptions' => [
'allowClear' => true,
'multiple' => true
],
]);
?>
</div>
Please, your reply will be appreciated. Thanks

Answer 1

I think you need to add the saved values as the initial data? Like so:
'value' => $savedDataArray, // initial value
http://demos.krajee.com/widget-details/select2#usage-tags

Answer 2

After much digging into the code, i found a way on how to display selected database values into a multi-select option using Yii Select2
My Model
public function getCandidateLanguage()
{
$langValues = (new \yii\db\Query())
->select('c.language_id AS id, l.lang_name')
->from('candidate_language c ')
->innerJoin('languages l','c.language_id = l.id')
->where('c.candidate_id='.$this->candidate_id)
->orderBy('c.language_id')
->all();
return \yii\helpers\ArrayHelper::map($langValues,'id','lang_name');
}
My View
use kartik\widgets\Select2;
<?php
//the line below is to fetch the array key of $model->getCandidateLanguage() array
$lang->id = array_keys($model->getCandidateLanguage()); // value to initialize
echo Select2::widget([
'model' => $lang,
'attribute' => 'id',
'data' => $model->getAllLanguages(),
'options' => ['placeholder' => 'Choose multiple languages'],
'pluginOptions' => [
'allowClear' => true,
'multiple' => true,
'tags' => true,
],
]);
?>
Hope it help someone who is facing the same issue.