Class: QgsMapLayerStore

class qgis.core.QgsMapLayerStore(parent: QObject = None)

Bases: PyQt5.QtCore.QObject

Constructor for QgsMapLayerStore.

A storage object for map layers, in which the layers are owned by the store and have their lifetime bound to the store.

New in version 3.0.

Parameters

parent

addMapLayer(self, layer: QgsMapLayer) → QgsMapLayer

Add a layer to the store. Ownership of the layer is transferred to the store.

The layersAdded() and layerWasAdded() signals will always be emitted. If you are adding multiple layers at once, you should use addMapLayers() instead.

Parameters

layer (QgsMapLayer) – A layer to add to the store

Return type

QgsMapLayer

Returns

None if unable to add layer, otherwise pointer to newly added layer

See also

addMapLayers()

Note

Use addMapLayers() if adding more than one layer at a time.

See also

addMapLayers()

addMapLayers(self, layers: Iterable[QgsMapLayer]) → List[QgsMapLayer]

Add a list of layers to the store. Ownership of the layers is transferred to the store.

The layersAdded() and layerWasAdded() signals will always be emitted.

Parameters

layers (Iterable[QgsMapLayer]) – A list of layer which should be added to the store.

Note

If a layer with the same id is already in the store it is not added again, but if the validity of the layer has changed from False to True, the layer data source is updated to the new one.

Return type

List[QgsMapLayer]

Returns

a list of the map layers that were added successfully. If a layer already exists in the store, it will not be part of the returned list.

See also

addMapLayer()

allLayersRemoved

Emitted when all layers are removed, before layersWillBeRemoved() and layerWillBeRemoved() signals are emitted. The layersWillBeRemoved() and layerWillBeRemoved() signals will still be emitted following this signal. You can use this signal to do easy (and fast) cleanup. [signal]

childEvent()
connectNotify()
count(self) → int

Returns the number of layers contained in the store.

Return type

int

customEvent()
disconnectNotify()
isSignalConnected()
layerRemoved

Emitted after a layer was removed from the store.

Parameters

layerId (str) – The ID of the layer removed.

Note

Consider using layersRemoved() instead

See also

layerWillBeRemoved() [signal]

layerWasAdded

Emitted when a layer was added to the store.

Note

Consider using layersAdded() instead

See also

layersAdded() [signal]

Parameters

layer (QgsMapLayer) –

layerWillBeRemoved

Emitted when a layer is about to be removed from the store.

Parameters

layerId (str) – The ID of the layer to be removed.

Note

Consider using layersWillBeRemoved() instead.

See also

layerRemoved() [signal]

layerWillBeRemoved(self, layer: QgsMapLayer) Emitted when a layer is about to be removed from the store.

Parameters

layer – The layer to be removed.

Note

Consider using layersWillBeRemoved() instead.

See also

layerRemoved() [signal]

layersAdded

Emitted when one or more layers were added to the store.

Parameters

layers (Iterable[QgsMapLayer]) – List of layers which have been added.

See also

layerWasAdded() [signal]

layersRemoved

Emitted after one or more layers were removed from the store.

Parameters

layerIds (Iterable[str]) – A list of IDs of the layers which were removed.

See also

layersWillBeRemoved() [signal]

layersWillBeRemoved

Emitted when one or more layers are about to be removed from the store.

Parameters

layerIds (Iterable[str]) – A list of IDs for the layers which are to be removed.

See also

layersRemoved() [signal]

layersWillBeRemoved(self, layers: Iterable[QgsMapLayer]) Emitted when one or more layers are about to be removed from the store.

Parameters

layers – A list of layers which are to be removed.

See also

layersRemoved() [signal]

mapLayer(self, id: str) → QgsMapLayer

Retrieve a pointer to a layer by layer id.

Parameters

id (str) – ID of layer to retrieve

Return type

QgsMapLayer

Returns

matching layer, or None if no matching layer found

See also

mapLayers()

mapLayers(self) → object

Returns a map of all layers by layer ID.

See also

mapLayer()

See also

layers()

Return type

object

mapLayersByName(self, name: str) → List[QgsMapLayer]

Retrieve a list of matching layers by layer name.

Parameters

name (str) – name of layers to match

Return type

List[QgsMapLayer]

Returns

list of matching layers

See also

mapLayer()

See also

mapLayers()

receivers()
removeAllMapLayers(self)

Removes all registered layers. These layers will also be deleted.

Note

Calling this method will cause the removeAll() signal to be emitted.

See also

removeMapLayer()

removeMapLayer(self, id: str)

Remove a layer from the store by layer id.

The specified layer will be removed from the store. The layer will also be deleted.

Parameters

id (str) – ID of the layer to remove

See also

takeMapLayer()

removeMapLayer(self, layer: QgsMapLayer) Remove a layer from the store.

The specified layer will be removed from the store. The layer will also be deleted.

Parameters

layer – The layer to remove. None values are ignored.

See also

takeMapLayer()

removeMapLayers(self, layers: Iterable[QgsMapLayer])

Remove a set of layers from the store.

The specified layers will be removed from the store. These layers will also be deleted.

Parameters

layers (Iterable[QgsMapLayer]) – A list of layers to remove. None values are ignored.

See also

takeMapLayer()

See also

removeMapLayer()

removeMapLayersById(self, layerIds: Iterable[str])

Remove a set of layers from the store by layer ID.

The specified layers will be removed from the store. These layers will also be deleted.

Parameters

layerIds (Iterable[str]) – list of IDs of the layers to remove

See also

takeMapLayer()

See also

removeMapLayer()

Note

available in Python bindings as removeMapLayersById.

sender()
senderSignalIndex()
takeMapLayer(self, layer: QgsMapLayer) → QgsMapLayer

Takes a layer from the store. If the layer was owned by the store, the layer will be returned without deleting it. The caller takes ownership of the layer and is responsible for deleting it.

See also

removeMapLayer()

Parameters

layer (QgsMapLayer) –

Return type

QgsMapLayer

timerEvent()
transferLayersFromStore(self, other: QgsMapLayerStore)

Transfers all the map layers contained within another map layer store and adds them to this store. Note that other and this store must have the same thread affinity.

Parameters

other (QgsMapLayerStore) –

validCount(self) → int

Returns the number of valid layers contained in the store.

New in version 3.6.

Return type

int

validMapLayers(self) → object

Returns a map of all valid layers by layer ID.

See also

mapLayer()

See also

layers()

New in version 3.6.

Return type

object