Yii2 - ActiveForm example

ActiveForm with model
    
        <?php $form = ActiveForm::begin() ?>
        <?= $form->field($model, 'username')->textInput() ?>
        <?= $form->field($model, 'password')->passwordInput() ?>
        <?= Html::submitButton('Login', ['class' => 'btn btn-primary', 'name' => 'login-button']) ?>
        <?php ActiveForm::end() ?>
    
ActiveForm with model and custom url
    
        <?php $form = ActiveForm::begin(['action' => ['site/login']]) ?>
        <?= $form->field($model, 'username')->textInput() ?>
        <?= $form->field($model, 'password')->passwordInput() ?>
        <?= Html::submitButton('Login', ['class' => 'btn btn-primary', 'name' => 'login-button']) ?>
        <?php ActiveForm::end() ?>
    
ActiveForm without model
    
        <?= Html::beginForm() ?>
        <label>Username</label>
        <?= Html::input('text', 'LoginForm[username]', null, ['class' => 'form-group form-control']) ?>
        <label>Password</label>
        <?= Html::input('text', 'LoginForm[password]', null, ['class' => 'form-group form-control']) ?>
        <?= Html::submitButton('Login', ['class' => 'btn btn-primary form-group']) ?>
        <?= Html::endForm() ?>
    
ActiveForm without model and custom url
    
        <?= Html::beginForm(['site/login'], 'post') ?>
        <label>Username</label>
        <?= Html::input('text', 'LoginForm[username]', null, ['class' => 'form-group form-control']) ?>
        <label>Password</label>
        <?= Html::input('text', 'LoginForm[password]', null, ['class' => 'form-group form-control']) ?>
        <?= Html::submitButton('Login', ['class' => 'btn btn-primary form-group']) ?>
        <?= Html::endForm() ?>