[Gvsig_english] SUGGESTED FUNCTIONALITY gvSIG 1.9 (BN 1253) -- Permanent Filter Shapefiles

[Simon Cropper (Botanicus Australia Pty Ltd)]

Ben,

You would have noted in my flotilla of emails that I hit a range of 
problems, some specifically related to joined tables.

I circumvented this by using the "import fields" option and basically 
sucked the needed fields into my existing shapefile. As all my data in 
and out of gvSIG have primary keys it was relatively easy once I found 
the tool gvSIG uses.

In regards to the 'expression' filter it only slightly varies from the 
'Unique Values' option. It appears to allow you to have more complex 
conditions rather than just those unique values expressed in the field. 
Curiously it does seem to behave differently when using the select tool. 
A 'transparent' polygon in the 'expression' filter option can be seen 
with the 'information' tool but not selected, while the 'transparent' 
polygon in the 'unique values' option can be seen by the 'information' 
tool and can be selected. Not sure if this is by design or not.

As I indicated to Antonio, I think that when applying a filter to a 
shapefile all geometries and their associated attributes, labeling, etc 
should be invisible to the system. Although I don't really no the 
nuances of the system, I presume this could be achieved by modifying the 
"gvSIG shp driver", which I presume sits between the core system and all 
the various extensions.

Cheers Simon

Simon Cropper
Botanicus Australia Pty Ltd
PO Box 160, Sunshine, Victoria 3020.
P: 9311 5822. M: 041 830 3437.
mailto: scropper at botanicusaustralia.com.au 
<mailto:scropper at botanicusaustralia.com.au>
web: www.botanicusaustralia.com.au <http://www.botanicusaustralia.com.au>


On 8/01/2010 9:27 PM, Benjamin Ducke wrote:
> Last time I checked, the "Expression" type filter you mention
> below did not work on fields joined from an external table.
> I think this is the problem that Simon ran into.
>
> Ben
>
> ----- Original Message -----
> From: "Antonio Falciano"<afalciano at yahoo.it>
> To: "Users and Developers mailing list"<gvsig_internacional at listserv.gva.es>
> Sent: Friday, January 8, 2010 11:21:29 AM GMT +01:00 Amsterdam / Berlin / Bern / Rome / Stockholm / Vienna
> Subject: Re: [Gvsig_english] SUGGESTED FUNCTIONALITY gvSIG 1.9 (BN 1253) -- Permanent Filter Shapefiles
>
> Il 08/01/2010 8.02, Simon Cropper (Botanicus Australia Pty Ltd) ha scritto:
>    
>> Hi,
>>
>> I was a little surprised not to find the ability to apply a
>> permanent filter to a shapefile based on the attributes in a table.
>> Say for example you wished only to show the polygons of a particular
>>   vegetation type. At present, this appears only way to do this is
>> exporting those geometries to a new file.
>>      
> Simon,
> there's actually the possibility to define a quite close "definition query":
> Layer Properties -->  Simbology tab -->  Categories tree -->  Expressions
> option -->  click on New expression of filter -->  ...and so on
> The only missing feature is that the filter is not applied to the table
> of attributes. Hope this helps!
>
> Cheers,
> Antonio
>
>