Re: Hashes (in general)

Tuesday, June 9, 2009, 4:57:11 PM, Brian Pontarelli wrote:
>
> With the proper wrapper you can access the Java Map facility (i.e.,
> you can use non-string keys; see Attila's answer), but the FTL hash
> type is defined as something that associates *strings* with arbitrary
> values. So it's not the same as Java's Map-s. For that reason
> myMap[key] will always expect a string in FTL. Anyway, I think that a
> template language should rather have something like Java's Map-s than
> something like FTL's hashes... but in 2.4 the hash type still only
> allow string keys.
>
>
> I agree. The template language capable of handling all the cases for
> non-string keys, include complex object keys. Seem simple to me. The
> whole wrapping process is somewhat interesting to me in general. Not
> sure if I like it or not yet.

Object wrapping gives you the power to show the "business objects" to
template in a way you want. It's quite powerful thing. However, it
also requires a FreeMarker "expert" around... But most users do OK for
the default wrapper (i.e, they don't have to be aware of wrapping),
except when it comes to Map-s, where the "keys must be strings" mess
starts...

> - Is there a way currently to get FM to stop wrapping the Map with an
> incorrect version that has String keys and null values?
>
> Does such thing happen? Maybe it's just that for missing items the
> Hash API (also the Java Map API) returns Null. So, myMap["1"] is null,
> because indeed there is no item with key "1" (only with key 1).
>
> Yeah. It doesn't unwrap the map directly. It creates a special Map
> that is an adapter with a custom entry set. It definitely can make things messy.

What did you use for unwrapping (and what was the ObjectWrapper)? If
you use BeansWrapper and call a plain Java method, it should give you
back the original Map.

> -bp
>

-- 
Best regards,
 Daniel Dekany


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