[mapguide-users] Filtering features on map with SelectFeatures function

[James Card]

On Thu, 29 Mar 2007 08:27:15 -0700, FGoulet <gouletf at dfo-mpo.gc.ca> wrote:

> I want to limit (filter) the number of features visible for a layer on a  
> map from server side code.
>
> I have aready successfully use the SelectFeatures function along with  
> QueryOptions to select a set of features on the map.
>
> Now I would like to make the map shows only the features returned by the  
> MgFeatureService.SelectFeatures function.

You'll probably want to modify the Filter element of the LayerDefinition  
so that the layer displays only your desired objects. The code below does  
that for one of our maps, but it isn't a very good example because it  
updates the Library resource rather than the layer in the Session  
repository.

   $QueryFilter='Drawing+%3D+%26apos%3B74%26apos%3B+AND+Dept+%3D+%26apos%3B136%26apos%3B'
   // Load the Query Match Layer Definition template into a PHP DOM object  
and
   // modify its Filter node so we're displaying the right building and  
floor.
   $doc = DOMDocument::load('QueryMatch.LayerDefinition.xml');
   $FilterNode = $doc->getElementsByTagName('Filter')->item(0);
   $FilterNode->nodeValue = $QueryFilter;
   $LayerDefinition = $doc->saveXML();
   $byteSource = new MgByteSource($LayerDefinition,  
strlen($LayerDefinition));
   $byteSource->SetMimeType(MgMimeType::Xml);
   $tempResourceID = new  
MgResourceIdentifier("Library://HumboldtFM/Layers/QueryMatch.LayerDefinition");
   $resourceService->SetResource($tempResourceID, $byteSource->GetReader(),  
null);

-- 
James Card
California CAD Solutions, Inc.
209 578-5580