Introduction
============

``pfg.drafts`` adds support for Plone users to save copies of PloneFormGen
forms in progress and restore the saved values later.  This removes the need
for users to fill out a lengthy form in one sitting.

The package adds a new display option for Form Folders, called "Form View with
Drafts".  If selected, a message is shown prompting the user to save a draft
of the form. (It also adds an additional button at the bottom of the form which
does the same thing.) If the user clicks this, they are presented with a
registration form to create a site account with which to associate the saved
data. After registration, the form is saved.

When the user returns to the form, if logged in, the form will be repopulated
with the saved values automatically.  If logged out, the user can click a link
to log in and restore their values. Then the form can be submitted normally
when the form is complete.

Compatibility
-------------

``pfg.drafts`` has been tested with Plone 4 and PloneFormGen 1.6.0.

Installation
------------

1. Add pfg.drafts to your buildout, and activate it via the Plone Add-ons
   control panel.
2. Go to the Security control panel and turn on "Enable self-registration"
   and "Let users select their own passwords". (If the latter is off,
   users will not be able to immediately register. You may want to add
   captcha to the registration form to prevent mechanical registrations.)
3. Go to the form for which you want to enable drafts, and change its
   display layout to "Form View with Drafts", using the Display menu.

Implementation Details
----------------------

Drafts are stored in a BTree in a custom tool (portal_fg_drafts), keyed by
form UID and user id.

To save form values, Javascript changes the action of the form to go to the
custom @@fg_save_draft view, which writes the values to portal_fg_drafts.
Any FileUpload objects are marshalled specially into a pickleable
FakeFieldStorage object.

When the form is visited, the custom display template (pfg_draft_view.cpt)
calls the portal_fg_draft tool's retrieveDraft method to repopulate the
request form with any saved data for the current form and user. Values in
the request take precedence over values from the draft, so the saved values
won't clobber new values after a validation error.

When the form is submitted, it is processed via the custom
pfg_draft_validate.vpy script.  This augments the submitted values with values
from the draft (such as fileuploads that were saved but cannot be repopulated)
and then processes the form normally.  If the form passes validation, the
saved draft (if any) is deleted from the portal_fg_drafts tool.

Credits
-------

``pfg.drafts`` was created by `Web Collective`_ and David Glick. Thanks to
Bryan Wilson and Fulvio Casali.

.. _`Web Collective`: http://webcollective.coop
