Add API to QgsProviderMetadata to determine valid layer types

which the provider can use to open a specified URI
qgis · Nov 6, 2020 · 51762dd · 51762dd
1 parent 8254b7d
commit 51762dd
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Showing 7 changed files with 97 additions and 2 deletions.
diff --git a/python/core/auto_generated/qgsprovidermetadata.sip.in b/python/core/auto_generated/qgsprovidermetadata.sip.in
@@ -209,6 +209,26 @@ priority for the same URI.
 
 The default implementation returns 0 for all URIs.
 
+.. warning::
+
+   Not all providers implement this functionality. Check whether :py:func:`~QgsProviderMetadata.capabilities` returns the
+   ProviderMetadataCapability.PriorityForUri to determine whether a specific provider metadata object
+   supports this method.
+
+.. versionadded:: 3.18
+%End
+
+    virtual QList< QgsMapLayerType > validLayerTypesForUri( const QString &uri ) const;
+%Docstring
+Returns a list of valid layer types which the provider can be used with when
+opening the specified ``uri``.
+
+.. warning::
+
+   Not all providers implement this functionality. Check whether :py:func:`~QgsProviderMetadata.capabilities` returns the
+   ProviderMetadataCapability.LayerTypesForUri to determine whether a specific provider metadata object
+   supports this method.
+
 .. versionadded:: 3.18
 %End
 

diff --git a/python/core/auto_generated/qgsproviderregistry.sip.in b/python/core/auto_generated/qgsproviderregistry.sip.in
@@ -281,9 +281,41 @@ Returns list of available providers by their keys
 Returns metadata of the provider or ``None`` if not found
 %End
 
-    QList< QgsProviderMetadata *> preferredProvidersForUri( const QString &uri ) const;
+    class ProviderCandidateDetails
+{
+%Docstring
+
+Contains information pertaining to a candidate provider.
+
+.. versionadded:: 3.18
+%End
+
+%TypeHeaderCode
+#include "qgsproviderregistry.h"
+%End
+      public:
+
+        ProviderCandidateDetails( QgsProviderMetadata *metadata, const QList< QgsMapLayerType > &layerTypes );
+%Docstring
+Constructor for ProviderCandidateDetails, with the specified provider ``metadata`` and valid candidate ``layerTypes``.
+%End
+
+        QgsProviderMetadata *metadata() const;
+%Docstring
+Returns the candidate provider metadata.
+%End
+
+        QList<QgsMapLayerType> layerTypes() const;
+%Docstring
+Returns a list of map layer types which are valid options for opening the
+target using this candidate provider.
+%End
+
+    };
+
+    QList< QgsProviderRegistry::ProviderCandidateDetails > preferredProvidersForUri( const QString &uri ) const;
 %Docstring
-Returns the metadata for the preferred provider(s) for opening the specified ``uri``.
+Returns the details for the preferred provider(s) for opening the specified ``uri``.
 
 The preferred provider is determined by comparing the priority returned by
 :py:func:`QgsProviderMetadata.priorityForUri()` for all registered providers, and selecting

diff --git a/src/core/providers/ept/qgseptprovider.cpp b/src/core/providers/ept/qgseptprovider.cpp
@@ -100,6 +100,16 @@ int QgsEptProviderMetadata::priorityForUri( const QString &uri ) const
   return 0;
 }
 
+QList<QgsMapLayerType> QgsEptProviderMetadata::validLayerTypesForUri( const QString &uri ) const
+{
+  const QVariantMap parts = decodeUri( uri );
+  QFileInfo fi( parts.value( QStringLiteral( "path" ) ).toString() );
+  if ( fi.fileName().compare( QLatin1String( "ept.json" ), Qt::CaseInsensitive ) == 0 )
+    return QList< QgsMapLayerType>() << QgsMapLayerType::PointCloudLayer;
+
+  return QList< QgsMapLayerType>();
+}
+
 bool QgsEptProviderMetadata::uriIsBlocklisted( const QString &uri ) const
 {
   const QVariantMap parts = decodeUri( uri );

diff --git a/src/core/qgsprovidermetadata.cpp b/src/core/qgsprovidermetadata.cpp
@@ -91,6 +91,11 @@ int QgsProviderMetadata::priorityForUri( const QString & ) const
   return 0;
 }
 
+QList<QgsMapLayerType> QgsProviderMetadata::validLayerTypesForUri( const QString &uri ) const
+{
+
+}
+
 bool QgsProviderMetadata::uriIsBlocklisted( const QString & ) const
 {
   return false;

diff --git a/src/core/qgsprovidermetadata.h b/src/core/qgsprovidermetadata.h
@@ -267,10 +267,26 @@ class CORE_EXPORT QgsProviderMetadata : public QObject
      *
      * The default implementation returns 0 for all URIs.
      *
+     * \warning Not all providers implement this functionality. Check whether capabilities() returns the
+     * ProviderMetadataCapability::PriorityForUri to determine whether a specific provider metadata object
+     * supports this method.
+     *
      * \since QGIS 3.18
      */
     virtual int priorityForUri( const QString &uri ) const;
 
+    /**
+     * Returns a list of valid layer types which the provider can be used with when
+     * opening the specified \a uri.
+     *
+     * \warning Not all providers implement this functionality. Check whether capabilities() returns the
+     * ProviderMetadataCapability::LayerTypesForUri to determine whether a specific provider metadata object
+     * supports this method.
+     *
+     * \since QGIS 3.18
+     */
+    virtual QList< QgsMapLayerType > validLayerTypesForUri( const QString &uri ) const;
+
     /**
      * Returns TRUE if the specified \a uri is known by this provider to be something which should
      * be blocklisted from the QGIS interface, e.g. an internal detail only.
@@ -605,6 +621,7 @@ class CORE_EXPORT QgsProviderMetadata : public QObject
     QMap<QString, QgsAbstractProviderConnection *> mProviderConnections;
 
 /// @endcond
+
 #endif
 
   private:

diff --git a/src/providers/pdal/qgspdalprovider.cpp b/src/providers/pdal/qgspdalprovider.cpp
@@ -162,6 +162,16 @@ int QgsPdalProviderMetadata::priorityForUri( const QString &uri ) const
   return 0;
 }
 
+QList<QgsMapLayerType> QgsPdalProviderMetadata::validLayerTypesForUri( const QString &uri ) const
+{
+  const QVariantMap parts = decodeUri( uri );
+  QFileInfo fi( parts.value( QStringLiteral( "path" ) ).toString() );
+  if ( fi.suffix().compare( QLatin1String( "las" ), Qt::CaseInsensitive ) == 0 || fi.suffix().compare( QLatin1String( "laz" ), Qt::CaseInsensitive ) == 0 )
+    return QList<QgsMapLayerType>() << QgsMapLayerType::PointCloudLayer;
+
+  return QList<QgsMapLayerType>();
+}
+
 QString QgsPdalProviderMetadata::filters( QgsProviderMetadata::FilterType type )
 {
   switch ( type )

diff --git a/src/providers/pdal/qgspdalprovider.h b/src/providers/pdal/qgspdalprovider.h
@@ -62,6 +62,7 @@ class QgsPdalProviderMetadata : public QgsProviderMetadata
     QString encodeUri( const QVariantMap &parts ) const override;
     QVariantMap decodeUri( const QString &uri ) const override;
     int priorityForUri( const QString &uri ) const override;
+    QList< QgsMapLayerType > validLayerTypesForUri( const QString &uri ) const override;
     QString filters( FilterType type ) override;
 };