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Re: [udig-devel] Accessing selected feature attributes 
You mean it's using my windows username at this point, even though the
initial connection was made with the default postgres account?  It's
weird - I tried changing rights on the relevant DB and geometry_columns
table to match my OS username but not effect.  Ah well - it's not that
critical right now.

The code snippet is very helpful...

cheers

Murray



Jesse Eichar wrote:


On 11-Jan-07, at 1:57 PM, Murray Richardson wrote:


Jesse or others,

A couple quick questions for you:
(1) Is there a simple way to return attributes (say FID) for all selected features in a layer? I would like to use these values in statements to postgreSQL. I'm not clear on how to get them from the Layer Filter.
To get the selected features: Suppose you just want the FID: 
        ILayer layer=null;
// first create a query that restricts the attributes returned. Since we just want the FID then we don't need // any attributes because that is not an attribute it part of the Feature itself. // also use the Layer.getFilter() method to return the selected features. // the new String[0] parameter indicates that we don't want any attributes. We could have put an attribute/column // name to indicate the attributes that we want. Query query = new DefaultQuery(layer.getSchema().getTypeName(), layer.getFilter(), new String[0]); 


        IProgressMonitor monitor;
FeatureSource featureSource = layer.getResource(FeatureSource.class, monitor); 
        FeatureCollection features = featureSource.getFeatures(query);
        FeatureIterator featureIterator = features.features();
        try{
            while(featureIterator.hasNext() ){
                Feature feature=featureIterator.next();


                // do something.
// the features here will have no attributes or geometry but you can call getID(). // warning you can't call getBounds() cause there's no geometry. this is a bug that still needs to be fixed 
            }


        }finally{
            // don't forget to close the iterator...
            featureIterator.close();
        }

Here's an example of a Query that requests the attribute called streetname:
Query query = new DefaultQuery(layer.getSchema().getTypeName(), layer.getFilter(), new String[]{streername});
(2) Create Feature Type operation doesn't work on the postGISdataStore that I access through my postGIS host in the catalog tree. I get a "Failed to create Feature Type" error. This could be handy. Is there a simple solution?
Are you talking about the operation that you get when you right-click on a PostGis in the catalog? If so this probably means that as a user you don't have the access to make a feature type. I have tested it before and it does work, but it does require permission to create tables and to modify the Geomtrycolumns table. I don't know if it works on pre 8.1 versions of Postgres. 

Thanks,

Murray

_______________________________________________
User-friendly Desktop Internet GIS (uDig)
http://udig.refractions.net
http://lists.refractions.net/mailman/listinfo/udig-devel



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_______________________________________________
User-friendly Desktop Internet GIS (uDig)
http://udig.refractions.net
http://lists.refractions.net/mailman/listinfo/udig-devel


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