yii\widgets\ActiveField::getClientOptions PHP Method

    protected function getClientOptions()
    {
        $attribute = Html::getAttributeName($this->attribute);
        if (!in_array($attribute, $this->model->activeAttributes(), true)) {
            return [];
        }
        $enableClientValidation = $this->enableClientValidation || $this->enableClientValidation === null && $this->form->enableClientValidation;
        $enableAjaxValidation = $this->enableAjaxValidation || $this->enableAjaxValidation === null && $this->form->enableAjaxValidation;
        if ($enableClientValidation) {
            $validators = [];
            foreach ($this->model->getActiveValidators($attribute) as $validator) {
                /* @var $validator \yii\validators\Validator */
                $js = $validator->clientValidateAttribute($this->model, $attribute, $this->form->getView());
                if ($validator->enableClientValidation && $js != '') {
                    if ($validator->whenClient !== null) {
                        $js = "if (({$validator->whenClient})(attribute, value)) { {$js} }";
                    }
                    $validators[] = $js;
                }
            }
        }
        if (!$enableAjaxValidation && (!$enableClientValidation || empty($validators))) {
            return [];
        }
        $options = [];
        $inputID = $this->getInputId();
        $options['id'] = Html::getInputId($this->model, $this->attribute);
        $options['name'] = $this->attribute;
        $options['container'] = isset($this->selectors['container']) ? $this->selectors['container'] : ".field-{$inputID}";
        $options['input'] = isset($this->selectors['input']) ? $this->selectors['input'] : "#{$inputID}";
        if (isset($this->selectors['error'])) {
            $options['error'] = $this->selectors['error'];
        } elseif (isset($this->errorOptions['class'])) {
            $options['error'] = '.' . implode('.', preg_split('/\\s+/', $this->errorOptions['class'], -1, PREG_SPLIT_NO_EMPTY));
        } else {
            $options['error'] = isset($this->errorOptions['tag']) ? $this->errorOptions['tag'] : 'span';
        }
        $options['encodeError'] = !isset($this->errorOptions['encode']) || $this->errorOptions['encode'];
        if ($enableAjaxValidation) {
            $options['enableAjaxValidation'] = true;
        }
        foreach (['validateOnChange', 'validateOnBlur', 'validateOnType', 'validationDelay'] as $name) {
            $options[$name] = $this->{$name} === null ? $this->form->{$name} : $this->{$name};
        }
        if (!empty($validators)) {
            $options['validate'] = new JsExpression("function (attribute, value, messages, deferred, \$form) {" . implode('', $validators) . '}');
        }
        // only get the options that are different from the default ones (set in yii.activeForm.js)
        return array_diff_assoc($options, ['validateOnChange' => true, 'validateOnBlur' => true, 'validateOnType' => false, 'validationDelay' => 500, 'encodeError' => true, 'error' => '.help-block']);
    }

 /**
  * Useful to test other methods from ActiveField, that call ActiveField::getClientOptions()
  * but it's return value is not relevant for the test being run.
  */
 public function getClientOptions()
 {
     return $this->getClientOptionsEmpty ? [] : parent::getClientOptions();
 }