[TiddlyWeb] Tiddler class should support extended fields

[cdent]

From email discussion on this matter:

It's simple enough in the Tiddler object itself to just have the fields field as a dict, but inside the Stores and Serializations it could get complicated if there are no restrictions on the structure of the data. Does TiddlyWiki have any limitations there?

Do we _want_ extended fields to be on a "fields" attribute, or just in there as attributes?

[mahemoff]

The main thing I'm looking for in "fields" is to manage relationships. It's possible in some sense to do this via hyperlinks in the tiddler, but in some cases, more structure is required.

For example, I'm developing a comments system. I need a "subject" field on each comment pointing back to the thing it refers to, and a "creator" field for attribution. I would need to be able to run filters against a particular subject or creator.

[cdent]

See tiddlyweb/tiddler.py. Each Tiddler now has a fields field which can hold arbitrary fields. These are properly saved by the stores.

[FND]

[original comment by cdent (2008-09-25)]

changeset:6696 begins work on extended fields