Re: [Geotools-devel] First cut at adding parameter info to FunctionName

[Justin D. <jde...@op...>]

Ok, second attempt has been made and a new patch is available here:

  http://jira.codehaus.org/browse/GEOT-3569

To sum up:

* added org.opengis.parameter.Parameter to opengis module
* modified org.geotools.data.PArameter to implement the new interface
* FunctionName uses the new interface for its return type and arguments

Feedback welcome. I will try to write up a more formal proposal soon.

On Fri, May 6, 2011 at 7:07 PM, Jody Garnett <jod...@gm...> wrote:

> I started playing around with adding parameter info to FunctionName today.
> I attached a very rough page to this issue:
>
> http://jira.codehaus.org/browse/GEOT-3569
>
> By no means complete or ready to commit, but wanted to post it to foster
> discussion and get some initial feedback.
>
> So basically I tried to follow Jody's advice and reuse on of the existing
> "parameter" classes we have, which actually turned out to be troublesome.
> Basically here are the candidates i could find:
>
> 1. org.geotools.data.Parameter
> 2. org.opengis.parameter.ParameterDescriptor
>
> 1 would work generally but it is declared in gt main wheras the function
> interface lives in gt-opengis.
>
> Darn; sorry Justin I did not think of that.
>
> 2 sort of works but is (a) an absolute nightmare to program against
> (getName() not returning a string, etc..). And it does not really allow me
> to set min and max occurs cleanly. And quite honestly is really overkill for
> what we need.
>
> Yeah number (2) is horrible.
>
> So moving forward i see the following possibilities:
> 1. Stick with ParameterDescriptor even though it is really messy
>
> please no!
>
> 2. Factor out an interface for org.geotools.data.Parameter into gt-opengis
>
> Better idea; see below.
>
> 3. Roll our own new interface for Function parameters
>
> Only advantage here would be an exact 1/2 match for the filter capabilities
> document. I am really loath to introduce anything new (as have to make yet
> another set of dynamic user interfaces support classes etc...
>
> 4. Use some alternative that i did not find.
>
> 4.1. Move org.geotools.data.Parameter to gt-opengis
>
> We could also just move the code over; remember we originally wanted to
> combined gt-opengis and gt-api; but are stuck on a few issues (mostly
> ReferencedEnvelope making use of the CRS utility class internally).
>
> 4.2 Variation on 2+3 - make an interface for FunctionParameters; and make
> org.geotools.data.Parameter implement it?
>
> Thanks all. Feedback welcome.
>
> Thanks for looking at what is an annoying problem Justin; I am sorry I was
> not more clear (org.opengis.parameter.ParameterDescriptor is indeed a
> nightmare to use).
>
> Jody
>
>


-- 
Justin Deoliveira
OpenGeo - http://opengeo.org
Enterprise support for open source geospatial.