Create a simple z3cform

First, we define a schema with a title, author, and text field for our comment form:

from zope import interface, schema

class IComment(interface.Interface):
    title = schema.TextLine(title=u"Title")
    author = schema.TextLine(title=u"Author",
                             required=False)
    text = schema.TextLine(title=u"Text")

The comment form uses the schema definition to define and later render the form. Also we define a label that will show up above the form:

from z3c.form import form, field

class CommentForm(form.Form):
    fields = field.Fields(IComment)
    ignoreContext = True # don't use context to get widget data
    label = "Add a comment"

Next, we add a submit button to the form with a method to handle the form data after we submitted the form. We extract the data from the form request, and return to the form if there are validation errors, otherwise we proceed:

from z3c.form import button
    @button.buttonAndHandler(u'Post comment')
    def handleApply(self, action):
        data, errors = self.extractData()
        if errors:
            return
        if data.has_key('text'):
            print data['text'] # ... or do stuff

As last step, we have to wrap the form into a standard Plone page:

from plone.z3cform.layout import wrap_form
wrap_form(CommentForm)

If we put all these steps together, our comment.py file should look like this:

from zope import interface, schema
from z3c.form import form, field, button
from plone.z3cform.layout import wrap_form

class IComment(interface.Interface):
    title = schema.TextLine(title=u"Title")
    author = schema.TextLine(title=u"Author", required=False)
    text = schema.TextLine(title=u"Text")

class CommentForm(form.Form):
    fields = field.Fields(IComment)
    ignoreContext = True # don't use context to get widget data
    label = u"Add a comment"

    @button.buttonAndHandler(u'Post comment')
    def handleApply(self, action):
        data, errors = self.extractData()
        if data.has_key('title') and data.has_key('text'):
            print data['title'] # ... or do stuff

CommentView = wrap_form(CommentForm)

For more z3c.form schema details see http://docs.zope.org/z3c.form/browser/README.html.

The only thing left to do in order to use our form is to register it in the configure.zcml:

<configure
    xmlns="http://namespaces.zope.org/zope"
    xmlns:five="http://namespaces.zope.org/five"
    xmlns:browser="http://namespaces.zope.org/browser"
    i18n_domain="example.z3cformtutorial">

    <!-- Include z3c.form as dependency -->
    <include package="plone.app.z3cform" />

    <!-- Register the comment form -->
    <browser:page
        for="Products.CMFPlone.interfaces.IPloneSiteRoot"
        name="comment_form"
        class=".comment.CommentView"
        permission="zope2.View"
        />

</configure>

Start the Zope instance

$ ./bin/instance fg

Go to the ZMI and create a Plone instance with the name 'test' and the Generic Setup profile "Plone z3c.form support". Then, go to the following URL

http://localhost:8080/test/comment_form