Check if layer is a QGSVectorLayer from Python Plugin within QGIS

Question

I am trying to extend some concepts in the QGIS Workshop tutorial. Basically, I would like to check if the layer is of type "QGSVectorLayer". In the QGIS Python console, I am able to type

canvas = qgis.utils.iface.mapCanvas()
cLayer = canvas.currentLayer()
type(cLayer).__name__

with no problem. However, when attempting the same from the plugin, I get the following error message:

if type(self.cLayer).name == "QgsVectorLayer": NameError: global name 'cLayer' is not defined

The code is as follows:

def handleLayerChange(self, layer):
        self.cLayer = self.canvas.currentLayer()
        if self.cLayer:
            if type(self.cLayer).__name__ == "QgsVectorLayer":
                self.provider = self.cLayer.dataProvider()

Answer 1

You don't need to compare it using strings or the name of the type. You should just do:

 layer.type() == QgsMapLayer.VectorLayer

Answer 2

Another way is testing against the desired class type, like this:

from qgis.core import QgsVectorLayer

# ...
if isinstance(layer, QgsVectorLayer):
    # ...