plone.z3cform 0.2

A library that allows use of z3c.form with Zope 2 and Plone

=============
plone.z3cform
=============

plone.z3cform is a library that allows use of z3c.form with Zope 2 and
Plone.

Quick start
===========

Tons of examples of using ``z3c.form`` can be found online. This is a
simple example of a form for Plone:

>>> from zope import interface, schema
>>> from z3c.form import form, field, button
>>> from plone.z3cform import base

>>> class MySchema(interface.Interface):
... age = schema.Int(title=u"Age")

>>> class MyForm(form.Form):
... fields = field.Fields(MySchema)
... ignoreContext = True # don't try to get data from context
...
... @button.buttonAndHandler(u'Apply')
... def handleApply(self, action):
... data, errors = self.extractData()
... print data['age'] # ... or do stuff

>>> class MyView(base.FormWrapper):
... form = MyForm
... label = u"Please enter your age"

Note that we're using ``base.FormWrapper`` as a base class for our
browser view. We can register the ``MyView`` view just like any other
``browser:page``.

Only the ``MyView`` bit is specific to ``plone.z3cform``. The rest is
standard ``z3c.form`` stuff. For more details on the base FormWrapper
class, see the ``plone.z3cform.base`` module.

Please also refer to the `online documentation`_ for more details.

.. _online documentation: http://plone.org/documentation/how-to/easy-forms-with-plone3


WYSIWYG widget
==============

The ``wysiwyg`` package provides an implementation of the Plone
WYSIWYG widget compatible with ``z3c.form``. This will allow you to
use Kupu, FCKeditor and other editors compatible with the Plone
WYSIWYG interface in your ``z3c.form`` forms.

To use, simply set the widget factory for the widget you'd like to be
displayed with the WYSIWYG widget:

>>> from zope import interface, schema
>>> from z3c.form import form, field
>>> from z3c.form.interfaces import INPUT_MODE
>>> from plone.z3cform.wysiwyg.widget import WysiwygFieldWidget

>>> class IProfile(interface.Interface):
... name = schema.TextLine(title=u"Name")
... age = schema.Int(title=u"Age")
... bio = schema.Text(title=u"Bio")

>>> class MyForm(form.Form):
... fields = field.Fields(IProfile)
... fields['bio'].widgetFactory[INPUT_MODE] = WysiwygFieldWidget


Query select widget
===================

The ``queryselect`` module provides a query source compatible with
``z3c.formwidget.query`` which combines to a selection field that can
be queried.

The native value type for the widget is Archetypes UID collections.
The default implementation will simply search using the
``SearchableText`` index in the portal catalog.

This is how your form schema could look like:

>>> from zope import interface, schema
>>> from plone.z3cform.queryselect import ArchetypesContentSourceBinder

>>> class ISelection(interface.Interface):
... items = schema.Set(
... title=u"Selection",
... description=u"Search for content",
... value_type=schema.Choice(
... source=ArchetypesContentSourceBinder()))

Optionally, instead of storing Archetypes UIDs, you can choose to use
``persistent.wref``, i.e. weak references, instead of UIDs:

>>> from plone.z3cform.queryselect import uid2wref
>>> factory = uid2wref(ISelection['items'])

To store weak references instead of UIDs you would register such a
factory as a component adapting the context. The factory
automatically provides the interface which defines the field.
(XXX: Please rewrite this paragraph.)


Crud
====

This module gives you an abstract base class to make CRUD forms with.
These forms give you by default a tabular view of the objects, where
attributes of the object can be edited in-place. Please refer to the
``ICrudForm`` interface for more details.

>>> from plone.z3cform.crud import crud

Setup
-----

>>> from plone.z3cform.tests import setup_defaults
>>> setup_defaults()

A simple form
-------------

First, let's define an interface and a class to play with:

>>> from zope import interface, schema
>>> class IPerson(interface.Interface) :
... name = schema.TextLine()
... age = schema.Int()

>>> class Person(object):
... interface.implements(IPerson)
... def __init__(self, name=None, age=None):
... self.name, self.age = name, age
... def __repr__(self):
... return "<Person with name=%r, age=%r>" % (self.name, self.age)

For this test, we take the the name of our persons as keys in our
storage:

>>> storage = {'Peter': Person(u'Peter', 16),
... 'Martha': Person(u'Martha', 32)}

Our simple form looks like this:

>>> class MyForm(crud.CrudForm):
... update_schema = IPerson
...
... def get_items(self):
... return sorted(storage.items(), key=lambda x: x[1].name)
...
... def add(self, data):
... person = Person(**data)
... storage[str(person.name)] = person
... return person
...
... def remove(self, (id, item)):
... del storage[id]

This is all that we need to render a combined edit add form containing
all our items:

>>> from z3c.form.testing import TestRequest
>>> print MyForm(None, TestRequest())() \
... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
<div class="crud-form">...Martha...Peter...</div>

Editing items with our form
---------------------------

Before we start with editing objects, let's log all events that the
form fires for us:

>>> from zope.lifecycleevent.interfaces import IObjectModifiedEvent
>>> from plone.z3cform.tests import create_eventlog
>>> log = create_eventlog(IObjectModifiedEvent)

>>> request = TestRequest()
>>> request.form['crud-edit.Martha.widgets.select-empty-marker'] = u'1'
>>> request.form['crud-edit.Peter.widgets.select-empty-marker'] = u'1'
>>> request.form['crud-edit.Martha.widgets.name'] = u'Martha'
>>> request.form['crud-edit.Martha.widgets.age'] = 55
>>> request.form['crud-edit.Peter.widgets.name'] = u'Franz'
>>> request.form['crud-edit.Peter.widgets.age'] = 16
>>> request.form['crud-edit.buttons.edit'] = u'Apply changes'
>>> html = MyForm(None, request)()
>>> "Successfully updated" in html
True

Two modified events should have been fired:

>>> event1, event2 = log.pop(), log.pop()
>>> storage['Peter'] in (event1.object, event2.object)
True
>>> storage['Martha'] in (event1.object, event2.object)
True
>>> log
[]

If we don't make any changes, we'll get a message that says so:

>>> html = MyForm(None, request)()
>>> "No changes made" in html
True
>>> log
[]

Now that we renamed Peter to Franz, it would be also nice to have
Franz use 'Franz' as the id in the storage, wouldn't it?

>>> storage['Peter']
<Person with name=u'Franz', age=16>

We can override the CrudForm's ``before_update`` method to perform a
rename whenever the name of a person is changed:

>>> class MyRenamingForm(MyForm):
... def before_update(self, item, data):
... if data['name'] != item.name:
... del storage[item.name]
... storage[str(data['name'])] = item

Let's rename Martha to Maria. This will give her another key in our
storage:

>>> request.form['crud-edit.Martha.widgets.name'] = u'Maria'
>>> html = MyRenamingForm(None, request)()
>>> "Successfully updated" in html
True
>>> log.pop().object == storage['Maria']
True
>>> log
[]
>>> sorted(storage.keys())
['Maria', 'Peter']

Next, we'll submit the form for edit, but we'll make no changes.
Instead, we'll select one time. This shouldn't do anything, since we
clicked the 'Apply changes' button:

>>> request.form['crud-edit.Maria.widgets.name'] = u'Maria'
>>> request.form['crud-edit.Maria.widgets.age'] = 55
>>> request.form['crud-edit.Maria.widgets.select'] = [u'selected']
>>> html = MyRenamingForm(None, request)()
>>> "No changes" in html
True
>>> log
[]

And what if we do have changes *and* click the checkbox?

>>> request.form['crud-edit.Maria.widgets.age'] = 50
>>> html = MyRenamingForm(None, request)()
>>> "Successfully updated" in html
True
>>> log.pop().object == storage['Maria']
True
>>> log
[]

If we omit the name, we'll get an error:

>>> request.form['crud-edit.Maria.widgets.name'] = u''
>>> html = MyRenamingForm(None, request)()
>>> "There were some errors" in html
True
>>> "Required input is missing" in html
True

We expect an error message in the title cell of Maria:

>>> checkbox_pos = html.index('crud-edit.Maria.widgets.select-empty-marker')
>>> "Required input is missing" in html[checkbox_pos:]
True

Delete an item with our form
----------------------------

We can delete an item by selecting the item we want to delete and
clicking the "Delete" button:

>>> request = TestRequest()
>>> request.form['crud-edit.Peter.widgets.select'] = ['selected']
>>> request.form['crud-edit.buttons.delete'] = u'Delete'
>>> html = MyForm(None, request)()
>>> "Successfully deleted items" in html
True
>>> 'Franz' in html
False
>>> storage
{'Maria': <Person with name=u'Maria', age=50>}

Add an item with our form
-------------------------

>>> from zope.lifecycleevent.interfaces import IObjectCreatedEvent
>>> from plone.z3cform.tests import create_eventlog
>>> log = create_eventlog(IObjectCreatedEvent)

>>> request = TestRequest()
>>> request.form['crud-add.widgets.name'] = u'Daniel'
>>> request.form['crud-add.widgets.age'] = 28
>>> request.form['crud-add.buttons.add'] = u'Add'
>>> html = MyForm(None, request)()
>>> "Item added successfully" in html
True

Added items should show up right away:

>>> "Daniel" in html
True

>>> storage['Daniel']
<Person with name=u'Daniel', age=28>
>>> log.pop().object == storage['Daniel']
True
>>> log
[]

Render some of the fields in view mode
--------------------------------------

We can implement in our form a ``view_schema`` attribute, which will
then be used to view information in our form's table. Let's say we
wanted the name of our persons to be viewable only in the table:

>>> from z3c.form import field
>>> class MyAdvancedForm(MyForm):
... update_schema = field.Fields(IPerson).select('age')
... view_schema = field.Fields(IPerson).select('name')
... add_schema = IPerson

>>> print MyAdvancedForm(None, TestRequest())() \
... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
<div class="crud-form">...Daniel...Maria...</div>

We can still edit the age of our Persons:

>>> request = TestRequest()
>>> request.form['crud-edit.Maria.widgets.age'] = 40
>>> request.form['crud-edit.Daniel.widgets.age'] = 35
>>> request.form['crud-edit.buttons.edit'] = u'Apply Changes'
>>> html = MyAdvancedForm(None, request)()
>>> "Successfully updated" in html
True

>>> storage['Maria'].age
40
>>> storage['Daniel'].age
35

We can still add a Person using both name and age:

>>> request = TestRequest()
>>> request.form['crud-add.widgets.name'] = u'Thomas'
>>> request.form['crud-add.widgets.age'] = 28
>>> request.form['crud-add.buttons.add'] = u'Add'
>>> html = MyAdvancedForm(None, request)()
>>> "Item added successfully" in html
True
>>> len(storage)
3
>>> storage['Thomas']
<Person with name=u'Thomas', age=28>

Our form can also contain links to our items:

>>> class MyAdvancedLinkingForm(MyAdvancedForm):
... def link(self, item, field):
... if field == 'name':
... return 'http://en.wikipedia.org/wiki/%s' % item.name

>>> print MyAdvancedLinkingForm(None, TestRequest())() \
... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
<div class="crud-form">...
...<a href="http://en.wikipedia.org/wiki/Daniel"...
...<a href="http://en.wikipedia.org/wiki/Maria"...
...<a href="http://en.wikipedia.org/wiki/Thomas"...
</div>

What if we wanted the name to be both used for linking to the item
*and* for edit? We can just include the title field twice:

>>> class MyAdvancedLinkingForm(MyAdvancedLinkingForm):
... update_schema = IPerson
... view_schema = field.Fields(IPerson).select('name')
... add_schema = IPerson

>>> print MyAdvancedLinkingForm(None, TestRequest())() \
... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
<div class="crud-form">...
...<a href="http://en.wikipedia.org/wiki/Thomas"...Thomas...</a>...
</div>

We can now change Thomas's name and see the change reflected in the
Wikipedia link immediately:

>>> request = TestRequest()
>>> for name in 'Daniel', 'Maria', 'Thomas':
... request.form['crud-edit.%s.widgets.name' % name] = storage[name].name
... request.form['crud-edit.%s.widgets.age' % name] = storage[name].age
>>> request.form['crud-edit.Thomas.widgets.name'] = u'Dracula'
>>> request.form['crud-edit.buttons.edit'] = u'Apply Changes'

>>> print MyAdvancedLinkingForm(None, request)() \
... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
<div class="crud-form">...
...<a href="http://en.wikipedia.org/wiki/Dracula"...Dracula...</a>...
</div>
>>> storage['Thomas'].name = u'Thomas'

Don't render one part
---------------------

What if we wanted our form to display only one part, that is, only the
add *or* the edit form. Our CrudForm can implement
``editform_factory`` and ``addform_factory`` to override one or both
forms. Seeting one of these to ``crud.NullForm`` will make them
disappear:

>>> class OnlyEditForm(MyForm):
... addform_factory = crud.NullForm
>>> html = OnlyEditForm(None, TestRequest())()
>>> 'Edit' in html, 'Add' in html
(True, False)

>>> class OnlyAddForm(MyForm):
... editform_factory = crud.NullForm
>>> html = OnlyAddForm(None, TestRequest())()
>>> 'Edit' in html, 'Add' in html
(False, True)

Render only in view, and define own actions
-------------------------------------------

Sometimes you want to present a list of items, possibly in view mode
only, and have the user select one or more of the items to perform
some action with them. We'll present a minimal example that does this
here.

We can simply leave the ``update_schema`` class attribute out (it
defaults to ``None``). Furthermore, we'll need to override the
ediform_factory with our custom version that provides other buttons
than the 'edit' and 'delete' ones:

>>> from pprint import pprint
>>> from z3c.form import button

>>> class MyEditForm(crud.EditForm):
... @button.buttonAndHandler(u'Capitalize', name='capitalize')
... def handle_capitalize(self, action):
... self.status = u"Please select items to capitalize first."
... selected = self.selected_items()
... if selected:
... self.status = u"Capitalized items"
... for id, item in selected:
... item.name = item.name.upper()

>>> class MyCustomForm(crud.CrudForm):
... view_schema = IPerson
... editform_factory = MyEditForm
... addform_factory = crud.NullForm # We don't want an add part.
...
... def get_items(self):
... return sorted(storage.items(), key=lambda x: x[1].name)

>>> request = TestRequest()
>>> html = MyCustomForm(None, TestRequest())()
>>> "Delete" in html, "Apply changes" in html, "Capitalize" in html
(False, False, True)
>>> pprint(storage)
{'Daniel': <Person with name=u'Daniel', age=35>,
'Maria': <Person with name=u'Maria', age=40>,
'Thomas': <Person with name=u'Thomas', age=28>}

>>> request.form['crud-edit.Thomas.widgets.select'] = ['selected']
>>> request.form['crud-edit.buttons.capitalize'] = u'Capitalize'
>>> html = MyCustomForm(None, request)()
>>> "Capitalized items" in html
True
>>> pprint(storage)
{'Daniel': <Person with name=u'Daniel', age=35>,
'Maria': <Person with name=u'Maria', age=40>,
'Thomas': <Person with name=u'THOMAS', age=28>}

We *cannot* use any of the other buttons:

>>> del request.form['crud-edit.buttons.capitalize']
>>> request.form['crud-edit.buttons.delete'] = u'Delete'
>>> html = MyCustomForm(None, request)()
>>> "Successfully deleted items" in html
False
>>> 'Thomas' in storage
True

Changelog
=========

0.2 - 2008-06-20
----------------

- fix usage of NumberDataConverter with zope.i18n >= 3.4 as the previous test
setup was partial and did not register all adapters from z3c.form (some of
them depends on zope >= 3.4)
[gotcha, jfroche]

- more tests
[gotcha, jfroche]

0.1 - 2008-05-21
----------------

* Provide and *register* default form and subform templates. These
allow forms to be used with the style provided in this package
without having to declare ``form = ViewPageTemplateFile('form.pt')``.

This does not hinder you from overriding with your own ``form``
attribute like usual. You can also still register a more
specialized IPageTemplate for your form.

* Add custom FileUploadDataConverter that converts a Zope 2 FileUpload
object to a Zope 3 one before handing it to the original
implementation. Also add support for different enctypes.
[skatja, nouri]

* Added Archetypes reference selection widget (queryselect)
[malthe]

* Moved generic Zope 2 compatibility code for z3c.form and a few
goodies from Singing & Dancing into this new package.
[nouri]