I am writing a plugin for QGIS 3.8

I have two layers,

  • drop_layer and
  • Fibre Cable.

I want to copy all features from the drop_layer and append to Fibre cable layer.

I use a function to create drop_layer using some processing tools. Then I use following function merge_to_original_Fibre_layer to copy all features of this "drop_layer" to another existing layer "Fibre cable". All these functions are part of the main class.

def merge_to_original_Fibre_layer(self):
    dlayer = self.drop_layer.getFeatures()
    layerObject = QgsProject.instance().mapLayersByName("Fibre Cable")[0]
    features = []
    for f in dlayer:

When I run the code, all the features of "drop_layer" are getting copied to "Fibre Cable" layer. I see this when I open the attribute table of the layer "Fibre Cable". Even I am able to zoom map to these features.

The problem is I cannot see the geometry of these newly added features on the map. What I am doing wrong?

  • Try layerObject.updateExtents(). Jan 17, 2022 at 0:48
  • Tried your advice. Still the added features are not visible. :( Jan 17, 2022 at 5:12
  • Replace the last 3 lines in your function with: layerObject.dataProvider().addFeatures(features)
    – Ben W
    Jan 17, 2022 at 8:50
  • You will find this section of the pyqgis developer cookbook useful: docs.qgis.org/3.16/en/docs/pyqgis_developer_cookbook/…
    – Ben W
    Jan 17, 2022 at 10:13
  • @Ben W, tried your advice. still added features are not visible. ;( Jan 17, 2022 at 12:35

1 Answer 1


The code was fine. The issue was with rule-based symbology. Fibre Cable layer had an attribute rule-based symbology. I added the required attributes to the added features and features were visible.

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