Forms.md

Forms

There are two main usages of forms in Drupal - altering existing forms or creating new ones. CWTool provides tool for both in similar ways.

Altering forms

Alters for existing forms (not defined by the module) should be registered in hook_form_NAME_alter() and a static class method (class::alter) should add the necessary alterations.

Adding new submit or validation callbacks via CW/Util/FormUtil:

class SomeExistingForm {
	public static function alter(&$form, &$form_state) {
		FormUtil::registerSubmitCallback($form, [__CLASS__, 'submit']);
	}
	
	public static function submit(&$form, &$form_state) { }
}

Creating new forms

For custom forms subclass CW\Form\FormBuilder:

class MyForm extends CW\Form\FormBuilder {
	public static function build($form, $form_state) {
		$form['submit'] = ['#type' => 'submit', 'value' => t('Submit')];
		return $form;
	}
	
	public static function submit(&$form, &$form_state) {
		// Do some action.
	}
}

// Calling the form:
$form = MyForm::get();
$html = drupal_render($form);

Adding input arguments to the form can be done when instantiating the form:

class PurchaseForm extends CW\Form\FormBuilder {
	public static function build($form, $form_state, $product, $buyer) {
		// ...
	}

	// ...
}

$form = PurchaseForm::get($purchasedProduct, $currentUser);
$html = drupal_render($form);

Form status value helpers

Working with the form_state array is a bit of a hassle. To have a more organized handling of form values you can use the FormState and NodeFormState classes to wrap the form_state variable into.

Example for a generic form

function some_form_submit($form, &$form_state) {
  $result = new FormState($form_state);
  $var1 = $result->val('var1');
  $selection = $result->val('selection');
  
  // Or using the nested accessor:
  $username = $result->getWrappedVales()->user->info->name->_value();
}

Example for node forms

The NodeFormState subclass has node specific accessors:

function some_node_form($form, &$form_state) {
  $result = new NodeFormState($form_state);
  
  $body = $result->fieldValue('body');
}