Yii2, how to work with the checkboxlist field - yii2

Question

As I needed a checkbox list I decided to use the checkboxlist , but I cant seem to add the values into the DB, if im using the list it only stores the first value from the list instead of all checked checkboxes.
[['sort_abc'], 'string']//not working
[['sort_abc'], 'integer']//not working
<?=$form->field($model, 'sort_abc[]')->checkBoxLIst( ['1' => 'Item A', '2' => 'Item B', '3' => 'Item C'])->label($model->getAttributeLabel('sort_abc'));?>
DB field
sort_abc | varchar(255) | yes | NULL
Also how can I add a image before every checkbox.

Answer 1

Yii wont magically convert your array to string or (worse) integer. You may use virtual attributes defined by getters/setter to simplify whole thing:
public function getSortAbcArray() {
if (empty($this->sort_abs)) {
return [];
}
return explode(',', $this->sort_abc);
}
public function setSortAbcArray($value) {
$this->sort_abs = implode(',', array_filter($value));
}
Then use this new attribute in form:
<?= $form->field($model, 'sortAbcArray')
->checkBoxList(['1' => 'Item A', '2' => 'Item B', '3' => 'Item C'])
->label($model->getAttributeLabel('sort_abc')); ?>
And in model rules:
['sortAbcArray', 'each', 'rule' => ['integer']]
Then $model->sortAbcArray returns values as array and $model->sort_abc as string, where values are separated by commas.

Answer 2

You don't need to name as array the field: sort_abc[] -> sort_abc
Simply doing it, the model will store in its attribute the checked checkboxes values.
To save the selected values, in your controller you can put:
$post = Yii::$app->request->post();
if (count($post) > 0) {
$post['YourModel']['sort_abc'] = implode(",", $post['YourModel']['sort_abc']);
}
if ($model->load($post) && $model->save()) {
...
}