Skip to main content
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [udig-devel] Feature Caching 
It is a confusing class! ;)
The ShowViewInterceptor is exactly right for what I'm doing so I've changed everything over to use that, rather than filtering at the IGeoResource level - it definitely keeps everything much cleaner. Unfortunately, it still suffers from the same problem. Someone somewhere is caching things so that, in order to see the filter change, you have to remove the layer and add it back in again. It's now persisting the original Filter (i.e. the one in place when the layer was first created) as well, so even closing the application down and opening it up again doesn't refresh the data! I need to dig more...
The cache doesn't seem to be accessible from outside of the LayerResource class - I think everything's in ResourceCacheInterceptor instance which is held in the interceptors collection. Is there any way of clearing it or stopping it from caching the FeatureStore? Maybe I'm looking in the wrong place... 

Thanks for the pointers anyway.

Jesse Eichar wrote:

Hi Dave,
Take a look at LayerResource. That could be related to your issue. Or maybe not it is a confusing class :). The idea is that LayerResource is a decorator over the IGeoResource from the catalog. It provides a small framework that does 2 things.
1. Provides targets for interceptor which allow a developer to do things like override the CRS returned by the IGeoResource... Or apply filters to an IGeoResource. Related to that there is actually an existing Interceptor called ShowViewInterceptor which takes a filter from the StyleBlackboard (it also checks the Layer Blackboard) and when a FeatureSource is requested calls getView on the Datastore and returns that FeatureSource instead of the one returned by the IGeoResource. Sounds like that could be of interest to you. 2. Caches items that are resolved from the IGeoResource so the same FeatureSource is returned each time. The reason the same FeatureSource was for events and for Transactions to be consistent. I wouldn like to review that and see if it is still necessary because caching (like you are finding) can be annoying. 

Jesse
On Mon, Aug 24, 2009 at 12:28 PM, Dave S-B <dev-lists@xxxxxxxxxxxxxxxxxxxxx <mailto:dev-lists@xxxxxxxxxxxxxxxxxxxxx>> wrote: 

    ...and I'm using a MySql DataStore to get the data...

    Dave S-B wrote:

        I'm trying to work through a problem I'm having with a custom
        GeoResource and I could do with some pointers.

        In our application, users can select global named "datasets"
        to work with for their current session. Amongst a load of
        other things, this includes data filtering. So, from my custom
        IGeoResource's getFeatureSource() method, I'm returning a
        feature source with a filter based on the global dataset
        rules. This is all working fine when you first open a map or
        add this particular layer - it picks up the correct results
        based on the current datasets. But, if the user changes their
        dataset selection, no amount of map refreshing or opening and
        closing of maps will draw the correct data *even though* the
        getFeatureSource() method *is* returning a FeatureSource with
        the correct Query/Filter (it's just an FID filter). The only
        way to see the refreshed data is to shut down the application
        and re-open it.

        I'm having trouble working out where things are being cached
        because getFeatureSource() is getting called on every map
        refresh/pan/zoom so something is obviously looking for fresh
        information.

        Any ideas how I can get the map to refresh properly? I'm using
        1.2M5 SDK at the moment..

        Many Thanks
        Dave S-B
        New album - "Dark" - out now! Check it out on
        www.myspace.com/davesbsounds <http://www.myspace.com/davesbsounds>
        _______________________________________________
        User-friendly Desktop Internet GIS (uDig)
        http://udig.refractions.net
        http://lists.refractions.net/mailman/listinfo/udig-devel
        ------------------------------------------------------------------------


        No virus found in this incoming message.
        Checked by AVG - www.avg.com <http://www.avg.com> Version:
        8.5.409 / Virus Database: 270.13.65/2322 - Release Date:
        08/23/09 18:03:00



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


------------------------------------------------------------------------


No virus found in this incoming message.
Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.65/2322 - Release Date: 08/23/09 18:03:00

Back to the top