backend.form.extendFieldsBefore

Called before the form fields are defined

Example usage:

Event::listen('backend.form.extendFieldsBefore', function ((\Backend\Widgets\Form) $formWidget) {
    // Check that we're extending the correct Form widget instance
    if (
        !($formWidget->getController() instanceof \Winter\User\Controllers\Users)
        || !($formWidget->model instanceof \Winter\User\Models\User)
        || $formWidget->isNested
    ) {
        return;
    }

    // Here you can't use addFields() because it will throw you an exception because form is not yet created
    // and it does not have tabs and fields
    // For this example we will pretend that we want to add a new field named example_field
    $formWidget->fields['example_field'] = [
        'label' => 'Example field',
        'comment' => 'Your example field',
        'type' => 'text',
    ];
});

Or

$formWidget->bindEvent('form.extendFieldsBefore', function () use ((\Backend\Widgets\Form $formWidget)) {
    // Check that we're extending the correct Form widget instance
    if (
        !($formWidget->getController() instanceof \Winter\User\Controllers\Users)
        || !($formWidget->model instanceof \Winter\User\Models\User)
        || $formWidget->isNested
    ) {
        return;
    }

    // Here you can't use addFields() because it will throw you an exception because form is not yet created
    // and it does not have tabs and fields
    // For this example we will pretend that we want to add a new field named example_field
    $formWidget->fields['example_field'] = [
        'label' => 'Example field',
        'comment' => 'Your example field',
        'type' => 'text',
    ];
});