[Community] geoalchemy integration

[Eric Lemoine]

On Saturday, September 26, 2009, Sanjiv Singh <singhsanjivk at gmail.com> wrote:
> On Sat, Sep 26, 2009 at 7:27 PM, Eric Lemoine
> <eric.lemoine at camptocamp.com> wrote:
>> On Sat, Sep 26, 2009 at 3:45 PM, Eric Lemoine
>> <eric.lemoine at camptocamp.com> wrote:
>>> On Sat, Sep 26, 2009 at 2:50 PM, Sanjiv Singh <singhsanjivk at gmail.com> wrote:
>>>> On Sat, Sep 26, 2009 at 5:13 PM, Eric Lemoine
>>>> <eric.lemoine at camptocamp.com> wrote:
>>>>> Hi
>>>>>
>>>>> (sorry if it's not the proper forum for this discussion, but I know
>>>>> there may interested people listening here :-)
>>>>
>>>> We are all part of the gispython "community", aren't we ;)
>>>>
>>>>>
>>>>> I'd like that MapFish rely on GeoAlchemy, to share code and development.
>>>>>
>>>>> For this, we need that GeoAlchemy reads database geometry values as
>>>>> objects implementing the __geo_interface__.
>>>>>
>>>>> The easiest would be to make GeoAlchemy create Shapely geometry
>>>>> objects. But I don't think it'd be a good idea to make GeoAlchemy
>>>>> depend on Shapely, because Shapely isn't a pure-Python lib.
>>>>>
>>>>> So I've been thinking about adding the boolean option "shape" to
>>>>> GeoAlchemy's TypeEngine (GeometryBase). If this option is true
>>>>> GeoAlchemy will create a Shapely geometry object using
>>>>> shapely.wrk.loads() and will add as a property to the
>>>>> PersistentSpatialElement object.
>>>>>
>>>>> What do you think?
>>>>>
>>>>
>>>> That would be great.
>>>> Is it possible to implement this as a separate package? That would
>>>> ease up dependency management.
>>>
>>> Could you elaborate?
>
> Basically, if someone installs geoalchemy without Shapely and then
> turns shape=True he will
> run into problems. Although when someone turns shape=True, he would
> know what he is doing
> and will most likely have shapely installed. But the possibility of
> having a dependency issue does exist.

Right. I just don't see any simple way to address this at this point.

>
> But again we need not have a separate package if it makes it too complex.
>
>>>
>>> See attached patch to understand what I'm suggesting.
>>
>> and FYI I got the read part of MapFish to work with GeoAlchemy with
>> only the attached patch to GeoAlchemy.
>
> Thats awesome. Should I grant you commit to the bitbucket repo?

I'd be honored to. In any way, I'll send you my patches for review
before any commit.

Thanks,

> Or you may like to fork it and send me pull request.
>
> regards
> Sanjiv
>
>>
>> --
>> Eric Lemoine
>>
>> Camptocamp France SAS
>> Savoie Technolac, BP 352
>> 73377 Le Bourget du Lac, Cedex
>>
>> Tel : 00 33 4 79 44 44 96
>> Mail : eric.lemoine at camptocamp.com
>> http://www.camptocamp.com
>>
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-- 
Eric Lemoine

Camptocamp France SAS
Savoie Technolac, BP 352
73377 Le Bourget du Lac, Cedex

Tel : 00 33 4 79 44 44 96
Mail : eric.lemoine at camptocamp.com
http://www.camptocamp.com