When a form is based upon a model, the common way of creating this form in Yii is via the yii\widgets\ActiveForm class. In most cases, a form has a corresponding model which is used for data validation. If the model represents data from a database, then the model should be derived from the ActiveRecord class. If the model captures arbitrary input, it should be derived from the yii\base\Model class.
Let us create a registration form.
Step 1 − Inside the models folder, create a file called RegistrationForm.php with the following code.
<?php namespace app\models; use Yii; use yii\base\Model; class RegistrationForm extends Model { public $username; public $password; public $email; public $subscriptions; public $photos; /** * @return array customized attribute labels */ public function attributeLabels() { return [ 'username' => 'Username', 'password' => 'Password', 'email' => 'Email', 'subscriptions' => 'Subscriptions', 'photos' => 'Photos', ]; } } ?>
We have declared a model for our registration form with five properties − username, password, email, subscriptions, and photos.
Step 2 − To display this form, add the actionRegistration method to the SiteController.
public function actionRegistration() { $mRegistration = new RegistrationForm(); return $this->render('registration', ['model' => $mRegistration]); }
We create an instance of the RegistrationForm and pass it to the registration view. Now, it is time to create a view.
Step 3 − Inside the views/site folder, add a file called registration.php with the following code.
<?php use yii\bootstrap\ActiveForm; use yii\bootstrap\Html; ?> <div class = "row"> <div class = "col-lg-5"> <?php $form = ActiveForm::begin(['id' => 'registration-form']); ?> <?= $form->field($model, 'username') ?> <?= $form->field($model, 'password')->passwordInput() ?> <?= $form->field($model, 'email')->input('email') ?> <?= $form->field($model, 'photos[]')->fileInput(['multiple'=>'multiple']) ?> <?= $form->field($model, 'subscriptions[]')->checkboxList(['a' => 'Item A', 'b' => 'Item B', 'c' => 'Item C']) ?> <div class = "form-group"> <?= Html::submitButton('Submit', ['class' => 'btn btn-primary', 'name' => 'registration-button']) ?> </div> <?php ActiveForm::end(); ?> </div> </div>
We observe the following −
The ActiveForm::begin() function marks the beginning of the form. All the code between ActiveForm::begin() and ActiveForm::end() functions will be wrapped within the form tag.
To create a field in the form you should call the ActiveForm::field() method. It creates all the input and label tags. Input names are determined automatically.
For example, the password attribute will be RegistrationForm[password]. If you want an attribute to take an array, you should append [ ] to the attribute name.
Step 4 − If you go to the address bar of the web browser and type http://localhost:8080/index.php?r=site/registration, you will see our form.