Getting name of group that layer is in using PyQGIS?

Question

I've been using the "Layer List" plugin (https://plugins.qgis.org/plugins/layerList/) that does a great job of creating a text file with all the layer in a qgs project file.

I want to extend it to get the group and subgroup that the layer is in.

The desired result will be

Provider,Group,Subgroup,Name, Path, Filename.ext

ogr,Administration, Land,CL_TENURE_POLYGON_DC,D:/GIS/Data/DSE/Vicmap/VMCLTENURE/,CL_TENURE_POLYGON_DC.tab

I assume the change would be

def loadActiveLayers(self): 
self.dlgCreate.listWidget.clear() # Clear the list widget before it is filled again
canvas = iface.mapCanvas()
activeLayers = canvas.layers() # Create list with all active layers
layers = u"# Layer List - QGIS Plugin by Klas Karlsson\n" # Create list header and "test" line in a text string
for layer in reversed(activeLayers): # Repeat for all layers in the list
 layerType = layer.type() # Is it Vector or Raster?
 layerSource = layer.publicSource() # path or command for the layer source
 provider = layer.providerType() # Example org, gdal, wms, wfs, postgres, etc
 if layerType == QgsMapLayer.VectorLayer:
 layers = layers + (u"%s,%s,%s\n" % (provider, layer.name(), layerSource))

after layerSource add something for group and subgroup (maybe .layerTreeRoot() from https://qgis.org/api/classQgsLayerTreeGroup.html)

 self.dlgCreate.listWidget.addItem(layer.name()) # Add the layer name to the list

self.dlgCreate.listWidget.addItem(layer.?

 if layerType == QgsMapLayer.RasterLayer:
 layers = layers + (u"%s,%s,%s\n" % (provider, layer.name(), layerSource))
 self.dlgCreate.listWidget.addItem(layer.name()) # Add the layer name to the list
return layers # Send back all the layers in a text string ready to be saved to a file

Would other changes be required?

• GeorgeC: Looking at this further using lutraconsulting.co.uk/blog/2014/07/06/… I see we can use >>root=QgsProject.instance().layerTreeRoot() >>child0=root.children()[0] and >>print(child0.name()) to get the name of the group but I am not sure how to use it in the code as it needs to be the name of the group/subgroup that the current layer is in. Will the whole code structure need to be changed to go by looping through the group names and then the layers rather than the current process which is to loop through the layers?
• GeorgeC: I was waiting for a reply to my question about how exactly to use it...until then I can't confirm that it does what's needed.

Answer 1

Instead of using the layers from the QgsMapCanvas you could better iterate the root of the layer tree view (QgsProject.instance().layerTreeRoot().children()) like I show in How to create a text file containing layer names in QGIS?. In this way you could have direct access to layer tree view groups and layers. Having a QgsLayerTreeLayer you can easily go to the QgsMapLayer by calling my_tree_layer.layer().

However, if you want to stick to the way you're iterating layers, then you can still access the group a layer is in:

my_layer = iface.activeLayer() # Just for you to test
root = QgsProject.instance().layerTreeRoot()
tree_layer = root.findLayer(my_layer.id())
if tree_layer:
 layer_parent = tree_layer.parent()
 if layer_parent: 
 print("Layer parent: {}".format(layer_parent.name() or 'root'))
 group_parent = layer_parent.parent() # If you want to go up another level
 if group_parent: 
 print("Group parent: {}".format(group_parent.name() or 'root'))

Since you would use this repeatedly, based on the code snippet above you could create a function that gets a map layer and gives you group and subgroup.

• GeorgeC: I think I'll use the existing structure to make it easier... do I try your code after provider = layer.providerType() # in my code example? so for each layer it works on it get the group values?