Breaking forms into multiple fieldsets
z3c.form supports the grouping of form fields into what is known as groups. A form class may mix in z3c.form.group.GroupForm to gain support for groups, setting the groups variable to a list of Group subclasses. The Group base class behaves much like the Form base class, but is used only for grouping fields, and cannot have actions.
In Plone, groups are represented as fieldsets. The standard templates make these look like dynamic tabs, much like those we can find in the edit forms for most Plone content. For this reason, plone.supermodel provides a directive called model.fieldset(), which can be used to create fieldsets.
The z3c.form Group idiom is still supported, and can be mixed with the more declarative model.fieldset() approach. However, the latter is usually easier to use.
To illustrate fieldsets, let’s give customers the option to leave feedback on our pizza ordering form. To keep our main form short, we will put this in a separate fieldset. Note that there is still only one set of submit buttons, i.e. all fieldsets are submitted at once. This is purely for aesthetic effect.
from example.dexterityforms.interfaces import MessageFactory as _ from plone.autoform import directives as form from plone.supermodel import model from zope import schema ... class IPizzaOrder(model.Schema): # Main form name = schema.TextLine( title=_(u"Your full name"), ) address1 = schema.TextLine( title=_(u"Address line 1"), ) address2 = schema.TextLine( title=_(u"Address line 2"), required=False, ) postcode = schema.TextLine( title=_(u"Postcode"), constraint=postcodeConstraint, ) telephone = schema.ASCIILine( title=_(u"Telephone number"), description=_(u"We prefer a mobile number"), ) orderItems = schema.Set( title=_(u"Your order"), value_type=schema.Choice(source=availablePizzas) ) form.widget('notes', WysiwygFieldWidget) notes = schema.Text( title=_(u"Notes"), description=_(u"Please include any additional notes for delivery"), required=False ) # Feedback fieldset model.fieldset( 'feedback', label=_(u"Feedback"), fields=['feedbackNote', 'feedbackEmail'] ) feedbackNote = schema.Text( title=_(u"Feedback"), description=_(u"Please provide any feedback below"), required=False, ) feebackEmail = schema.TextLine( title=_(u"Email address"), description=_(u"If you'd like us to contact you, please give us an email address below"), required=False, ) ...
Since this approach uses form schema hints, the schema must derive from model.Schema and the form base class must extend plone.autoform.AutoExtensibleForm. In our example, we are using SchemaForm, a subclass of AutoExtensibleForm.
Above, we have declared a single fieldset, and listed the fields within it. Those fields not explicitly associated with a fieldset end up in the “default” fieldset. We also set a fieldset name and label. The label is optional.
It is possible to use the same fieldset name multiple times in the same form. This is often the case when we use the additional_schemata property to set secondary schemata for our form. In this case, the label from the first fieldset directive encountered will be used.