[Zope-CMF] [dev] type infos and 'add' actions - a proposal

[yuppie]

Hi!


This is a proposal for implementing one part of what we discussed in 
this thread:
http://mail.zope.org/pipermail/zope-cmf/2008-July/027500.html

Using add views instead of folder_factories for creating content makes 
it necessary to provide some kind of menu items for them. In CMF menu 
items are usually represented by 'actions'.


Type infos already define most data required for actions:

- 'id': can be reused

- 'title': can be reused; if we want action titles like 'Add File ...' 
instead of 'File' we can change that in the template

- 'description': has already the same purpose as in actions

- 'icon': 'content_icon' is a path relative to the site root, but we can 
use the same icon and compute the required absolute path

- 'available': can be computed using allowType of the container

- 'allowed': can be computed using isConstructionAllowed

Missing are these properties:

- 'category': can be hardcoded, e.g. as 'folder/add'

- 'url': requires a new type info property, I propose to use 'url_expr' 
to keep it in sync with normal Action objects

- 'visible': can be hardcoded as True


So instead of adding separate 'add' actions we can extend the type info 
classes, making them implement IAction as well.

listActions of the types tool would include type infos if they provide 
IAction *and* have an url specified.


As always, feedback is welcome.

Cheers,

     Yuppie