The indexes provided with Magma are really just simple examples. Robust applications will almost certainly want to define their own custom indexes.
That is your path to a clean solution. Make your own DateIndex that accepts a nil. Just override #canIndex: in addition to #indexHashForIndexObject:, et al...
On Jan 11, 2008 9:43 AM, Norberto Manzanos nmanzanos@gmail.com wrote:
Hi!
Is it a good idea avoid nil in magma indexes? This question rised when I tried MaDateIndex. Until this moment, I used String or Integer indexes having care to answer allways a String (an empty string if the object is nil) and an Integer (a zero if nil). But with dates there is a conceptual problem: there is not a null date. In some applications, business stuff, for example, you can think in an ovbiously unused date (01-01-1500, for example) that acts as a null date. It's a little dirty, but it would work. But in other applications every possible date has a meaning. And if the object could be inexistent in some cases, you have no choice: it's nil. That's my case, and I'm forced to use a StringIndex, converting the dates to Strings, answering an empty string if the object is nil. That's really dirty. Would'nt be better if magma indexes just ignore nil objects? Is it a requirement for magma that every object from a MagmaCollection must be present in all indexes? I hope there is something I misunderstood and there is a more elegant solution.
Regards Norberto
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