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Form Builder#

Form builder is only available since WoltLab Suite Core 5.2.

The migration guide for WoltLab Suite Core 5.2 provides some examples of how to migrate existing forms to form builder that can also help in understanding form builder if the old way of creating forms is familiar.

Advantages of Form Builder#

WoltLab Suite 5.2 introduces a new powerful way of creating forms: form builder. Before taking a closer look at form builder, let us recap how forms are created in previous versions: In general, for each form field, there is a corresponding property of the form's PHP class whose value has to be read from the request data, validated, and passed to the database object action to store the value in a database table. When editing an object, the property's value has to be set using the value of the corresponding property of the edited object. In the form's template, you have to write the <form> element with all of its children: the <section> elements, the <dl> elements, and, of course, the form fields themselves. In summary, this way of creating forms creates much duplicate or at least very similar code and makes it very time consuming if the structure of forms in general or a specific type of form field has to be changed.

Form builder, in contrast, relies on PHP objects representing each component of the form, from the form itself down to each form field. This approach makes creating forms as easy as creating some PHP objects, populating them with all the relevant data, and one line of code in the template to print the form.

Form Builder Components#

Form builder consists of several components that are presented on the following pages:

  1. Structure of form builder
  2. Form validation and form data
  3. Form node dependencies

In general, form builder provides default implementation of interfaces by providing either abstract classes or traits. It is expected that the interfaces are always implemented using these abstract classes and traits! This way, if new methods are added to the interfaces, default implementations can be provided by the abstract classes and traits without causing backwards compatibility problems.

AbstractFormBuilderForm#

To make using form builder easier, AbstractFormBuilderForm extends AbstractForm and provides most of the code needed to set up a form (of course without specific fields, those have to be added by the concrete form class), like reading and validating form values and using a database object action to use the form data to create or update a database object.

In addition to the existing methods inherited by AbstractForm, AbstractFormBuilderForm provides the following methods:

  • buildForm() builds the form in the following steps:

  • Call AbtractFormBuilderForm::createForm() to create the IFormDocument object and add the form fields.

  • Call IFormDocument::build() to build the form.
  • Call AbtractFormBuilderForm::finalizeForm() to finalize the form like adding dependencies.

Additionally, between steps 1 and 2 and after step 3, the method provides two events, createForm and buildForm to allow plugins to register event listeners to execute additional code at the right point in time. - createForm() creates the FormDocument object and sets the form mode. Classes extending AbstractFormBuilderForm have to override this method (and call parent::createForm() as the first line in the overridden method) to add concrete form containers and form fields to the bare form document. - finalizeForm() is called after the form has been built and the complete form hierarchy has been established. This method should be overridden to add dependencies, for example. - setFormAction() is called at the end of readData() and sets the form document’s action based on the controller class name and whether an object is currently edited. - If an object is edited, at the beginning of readData(), setFormObjectData() is called which calls IFormDocument::loadValuesFromObject(). If values need to be loaded from additional sources, this method should be used for that.

AbstractFormBuilderForm also provides the following (public) properties:

  • $form contains the IFormDocument object created in createForm().
  • $formAction is either create (default) or edit and handles which method of the database object is called by default (create is called for $formAction = 'create' and update is called for $formAction = 'edit') and is used to set the value of the action template variable.
  • $formObject contains the IStorableObject if the form is used to edit an existing object. For forms used to create objects, $formObject is always null. Edit forms have to manually identify the edited object based on the request data and set the value of $formObject.
  • $objectActionName can be used to set an alternative action to be executed by the database object action that deviates from the default action determined by the value of $formAction.
  • $objectActionClass is the name of the database object action class that is used to create or update the database object.

DialogFormDocument#

Form builder forms can also be used in dialogs. For such forms, DialogFormDocument should be used which provides the additional methods cancelable($cancelable = true) and isCancelable() to set and check if the dialog can be canceled. If a dialog form can be canceled, a cancel button is added.

If the dialog form is fetched via an AJAX request, IFormDocument::ajax() has to be called. AJAX forms are registered with WoltLabSuite/Core/Form/Builder/Manager which also supports getting all of the data of a form via the getData(formId) function. The getData() function relies on all form fields creating and registering a WoltLabSuite/Core/Form/Builder/Field/Field object that provides the data of a specific field.

To make it as easy as possible to work with AJAX forms in dialogs, WoltLabSuite/Core/Form/Builder/Dialog (abbreviated as FormBuilderDialog from now on) should generally be used instead of WoltLabSuite/Core/Form/Builder/Manager directly. The constructor of FormBuilderDialog expects the following parameters:

  • dialogId: id of the dialog element
  • className: PHP class used to get the form dialog (and save the data if options.submitActionName is set)
  • actionName: name of the action/method of className that returns the dialog; the method is expected to return an array with formId containg the id of the returned form and dialog containing the rendered form dialog
  • options: additional options:
  • actionParameters (default: empty): additional parameters sent during AJAX requests
  • destroyOnClose (default: false): if true, whenever the dialog is closed, the form is destroyed so that a new form is fetched if the dialog is opened again
  • dialog: additional dialog options used as options during dialog setup
  • onSubmit: callback when the form is submitted (takes precedence over submitActionName)
  • submitActionName (default: not set): name of the action/method of className called when the form is submitted

The three public functions of FormBuilderDialog are:

  • destroy() destroys the dialog, the form, and all of the form fields.
  • getData() returns a Promise that returns the form data.
  • open() opens the dialog.

Example:

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require(['WoltLabSuite/Core/Form/Builder/Dialog'], function(FormBuilderDialog) {
    var dialog = new FormBuilderDialog(
        'testDialog',
        'wcf\\data\\test\\TestAction',
        'getDialog',
        {
            destroyOnClose: true,
            dialog: {
                title: 'Test Dialog'
            },
            submitActionName: 'saveDialog'
        }
    );

    elById('testDialogButton').addEventListener('click', function() {
        dialog.open();
    });
});

Last update: 2021-01-15