When querying sublayers for all providers using

QgsProviderRegistry::querySublayers, if there is a preferred providers for a particular uri then ONLY return sublayers from these providers instead of iterating over all providers This cleans up the case that two providers can technically handle a uri, but where we definitely only want ONE of them to handle that uri. Specifically, while the OGR provider can technically open JSON files so reports that it can handle ept.json files, we only ever want to use the EPT point cloud provider for these as we know for certain that they are point cloud uris, not vector layers.
qgis · Jul 23, 2021 · c74f42c · c74f42c
1 parent e57193d
commit c74f42c
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Showing 2 changed files with 27 additions and 4 deletions.
diff --git a/src/core/providers/qgsproviderregistry.cpp b/src/core/providers/qgsproviderregistry.cpp
@@ -906,6 +906,10 @@ QList<QgsProviderSublayerDetails> QgsProviderRegistry::querySublayers( const QSt
   QList<QgsProviderSublayerDetails> res;
   for ( auto it = mProviders.begin(); it != mProviders.end(); ++it )
   {
+    // if we should defer this uri for other providers, do so
+    if ( shouldDeferUriForOtherProviders( uri, it->first ) )
+      continue;
+
     res.append( it->second->querySublayers( uri, flags, feedback ) );
     if ( feedback && feedback->isCanceled() )
       break;

diff --git a/tests/src/python/test_qgsproviderregistry.py b/tests/src/python/test_qgsproviderregistry.py
@@ -131,6 +131,29 @@ def testUnusableUriDetails(self):
         self.assertIn('LAZ', details.warning)
 
     def testSublayerDetails(self):
+        ept_provider_metadata = QgsProviderRegistry.instance().providerMetadata('ept')
+        ogr_provider_metadata = QgsProviderRegistry.instance().providerMetadata('ogr')
+
+        if ept_provider_metadata is not None:
+            # test querying a uri which should be blocklisted
+            self.assertFalse(QgsProviderRegistry.instance().querySublayers(unitTestDataPath() + '/point_clouds/ept/sunshine-coast/ept-build.json'))
+
+        if ept_provider_metadata is not None and ogr_provider_metadata is not None:
+            # test querying a uri which is technically capable of being opened by two providers, but which one provider is preferred
+            # in this case we are testing a ept.json file, which should ALWAYS be treated as a ept point cloud layer even though
+            # the OGR provider CAN technically open json files
+
+            # when we directly query ogr provider metadata it should report sublayers for the json file...
+            self.assertEqual([l.providerKey() for l in ogr_provider_metadata.querySublayers(
+                unitTestDataPath() + '/point_clouds/ept/sunshine-coast/ept.json', Qgis.SublayerQueryFlags(Qgis.SublayerQueryFlag.FastScan))], ['ogr'])
+
+            # ...and when we query ept provider metadata directly it should also report sublayers for ept.json files...
+            self.assertEqual([l.providerKey() for l in ept_provider_metadata.querySublayers(
+                unitTestDataPath() + '/point_clouds/ept/sunshine-coast/ept.json', Qgis.SublayerQueryFlags(Qgis.SublayerQueryFlag.FastScan))], ['ept'])
+
+            # ... but when we query the provider registry itself, it should ONLY report the ept provider sublayers
+            self.assertEqual([l.providerKey() for l in QgsProviderRegistry.instance().querySublayers(unitTestDataPath() + '/point_clouds/ept/sunshine-coast/ept.json', Qgis.SublayerQueryFlags(Qgis.SublayerQueryFlag.FastScan))], ['ept'])
+
         provider1 = TestProviderMetadata('p1')
         provider2 = TestProviderMetadata('p2')
 
@@ -142,10 +165,6 @@ def testSublayerDetails(self):
         self.assertCountEqual([p.providerKey() for p in QgsProviderRegistry.instance().querySublayers('test_uri')],
                               ['p1', 'p2'])
 
-        if QgsProviderRegistry.instance().providerMetadata('ept'):
-            # test querying a uri which should be blocklisted
-            self.assertFalse(QgsProviderRegistry.instance().querySublayers(unitTestDataPath() + '/point_clouds/ept/sunshine-coast/ept-build.json'))
-
 
 if __name__ == '__main__':
     unittest.main()