Configuring Form Builder

After this guide, you will have learned how to Configure the Form Builder through settings

Adding a New Form Element Inside “Create Elements”

Let’s say you have created your form element, and want to make it available inside the Form Builder. For that, you need some YAML configuration which looks as follows:

# we are now inside TYPO3:Form:presets:[presetName]
    # the definitions for your form element
      label: 'Your New Form Element'
      group: custom
      sorting: 200

To determine whether a form element is visible in the Form Builder, you must set formBuilder:group to a valid group. A form element group is used to visually group the available form elements together. In the default profile, the following groups are configured:

  • input
  • select
  • custom
  • container

The label is – as you might expect – the human-readable label, while the sorting determines the ordering of form elements inside their form element group.

Creating a New Form Element Group

All form element groups are defined inside formElementGroups inside the preset, so that’s how you can add a new group:

# we are now inside TYPO3:Form:presets:[presetName]
    sorting: 500
    label: 'My special custom group'

For each group, you need to specify a human-readable label, and the sorting (which determines the ordering of the groups).

Setting Default Values for Form Elements

When a form element is created, you can define some default values which are directly set on the form element. As an example, let’s imagine you want to build a ProgrammingLanguageSelect where the user can choose his favorite programming language.

In this case, we want to define some default programming languages, but the integrator who builds the form should be able to add custom options as well. These default options can be set in Settings.yaml using the formBuilder:predefinedDefaults key.

Here follows the full configuration for the ProgrammingLanguageSelect (which is an example taken from the TYPO3.FormExample package):

# we are now inside TYPO3:Form:presets:[presetName]
      'TYPO3.Form:SingleSelectRadiobuttons': TRUE
      templatePathPattern: 'resource://TYPO3.Form/Private/Form/SingleSelectRadiobuttons.html'

      # here follow the form builder specific options
        group: custom
        label: 'Programming Language Select'

        # we now set some defaults which are applied once the form element is inserted to the form
                _key: 'php'
                _value: 'PHP'
                _key: 'java'
                _value: 'Java etc'
                _key: 'js'
                _value: 'JavaScript'

Contrasting Use Case: Gender Selection

Inside Creating a new form element, we have implemented a special Gender Select. Let’s think a second about the differences between the Gender Select and the Programming Language Select examples:

For a Gender select field, the integrator using the form builder does not need to set any options for this form element, as the available choices (Female and Male) are predefined inside the form element template.

In the case of the programming language select, we only want to set some sensible defaults for the integrator, but want him to be able to adjust the values.

Choosing which strategy to use depends mostly on the expected usage patterns:

  • In the gender select example, if a new option is added to the list afterwards, this will directly be reflected in all forms which use this input field.
  • If you use predefinedDefaults, changing these will be only applied to new elements, but not to already existing elements.


In order to make the gender selection work nicely with the Form Builder, we should disable the options editor as follows (as the options should not be editable by the implementor):

# we are now inside TYPO3:Form:presets:[presetName]
        # Disable "options" editor
        options: null


The same distinction between using formBuilder:predefinedDefaults and the form element type definition directly can also be used to add other elements like Validators or Finishers.

Marking Validators and Finishers As Required

Sometimes, you want to simplify the Form Builder User Interface and make certain options easier for your users. A frequent use-case is that you want that a certain validator, like the StringLength validator, is always shown in the user interface as it is very often used.

This can be configured as follows:

# we are now inside TYPO3:Form:presets:[presetName]
  'TYPO3.Form:TextMixin': # or any other type here
            'TYPO3.Flow:StringLength': # or any other validator
              # mark this validator required such that it is always shown.
              required: true


The same works for Finishers, for example the following configuration makes the EmailFinisher mandatory:

# we are now inside TYPO3:Form:presets:[presetName]
            'TYPO3.Form:Email': # or any other finisher
              # mark this finisher required such that it is always shown.
              required: true

Finishing Up

You should now have some receipes at hand on how to modify the Form Builder. Read the next chapter for some more advanced help.