[Chandler-dev] is a unified displayName a good thing?

Alec Flett alecf at osafoundation.org
Thu Mar 30 17:06:38 PST 2006

So we have this great attribute, 'displayName' which is used all over 
the place from Block to CalendarEvent and comes in quite handy most of 
the time.

I've recently run into a snag with it however.

In the repository, you can indicate that an attribute is indexed by 
PyLucene simply by adding a 'indexed=True' to the attribute definition.

The problem is that from a user's perspective we only want to be 
searching 'Note'-based items... not all Items in the system. Further 
complicating this is that things like attributes are also Items.

This means that if you do a PyLucene search for "a" you'll get literally 
hundreds, if not thousands, of results, even if you only have "Welcome 
to Chandler" in your All collection. Now of course it is easy to filter 
out the items that don't derive from Note and only display them... but 
it seems like a lot of work to iterate 1000 items that we know will 
never be displayed just to get 1 result back.

There are a few options that I can think of, and I'll indicate my 
preference below:
1) change the repository so PyLucene only indexes one particular type of 
Item... maybe a specific subclass or something.
2) don't use displayName for user-visible Items, and don't put 
'indexed=True' on displayName. Instead, come up with a new attribute, 
say 'title' that shows up only on Note-based items, and put indexed=True 
on that attribute.

Either way the end result is that when you search PyLucene, we don't 
have to filter out 1000 non-Note items.

I vastly prefer the 2nd option, and I think it makes a lot of sense from 
a domain model perspective anyway.

I realize there is a lot of history here... (Andi says "Brian made me do 
that" when we found some oddities in chandler.pack) but honestly a 
Note-based item's "title" is a dynamic, changing part of a user's data, 
while a displayName tends to be a more static description of a well 
known Item. I see a semantic difference and we should probably reflect 
that in the schema.

When you're searching PyLucene, we don't want to say "only find these 
things" - instead we want the things to indicate if they want to be 
found. The title of an event wants to be found. The displayName of a 
MenuItem block doesn't!



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