.. _forms: Generating and Validating Forms =============================== Pecan provides no opinionated support for working with form generation and validation libraries, but it’s easy to import your library of choice with minimal effort. This article details best practices for integrating the popular forms library, `WTForms `_, into your Pecan project. Defining a Form Definition -------------------------- Let's start by building a basic form with a required ``first_name`` field and an optional ``last_name`` field. :: from wtforms import Form, TextField, validators class MyForm(Form): first_name = TextField(u'First Name', validators=[validators.required()]) last_name = TextField(u'Last Name', validators=[validators.optional()]) class SomeController(object): pass Rendering a Form in a Template ------------------------------ Next, let's add a controller, and pass a form instance to the template. :: from pecan import expose from wtforms import Form, TextField, validators class MyForm(Form): first_name = TextField(u'First Name', validators=[validators.required()]) last_name = TextField(u'Last Name', validators=[validators.optional()]) class SomeController(object): @expose(template='index.html') def index(self): return dict(form=MyForm()) Here's the Mako_ template file: .. _Mako: http://www.makeotemplates.org/ .. code-block:: html
${form.first_name.label}: ${form.first_name}
${form.last_name.label}: ${form.last_name}
Validating POST Values ---------------------- Using the same :class:`MyForm` definition, let's redirect the user if the form is validated, otherwise, render the form again. .. code-block:: python from pecan import expose, request from wtforms import Form, TextField, validators class MyForm(Form): first_name = TextField(u'First Name', validators=[validators.required()]) last_name = TextField(u'Last Name', validators=[validators.optional()]) class SomeController(object): @expose(template='index.html') def index(self): my_form = MyForm(request.POST) if request.method == 'POST' and my_form.validate(): # save_values() redirect('/success') else: return dict(form=my_form)