When I use QGIS Dissolve geoalgorithm as a standalone tool from the Processing Toolbox, the GUI looks like shown below. By selecting the
Input layer I am able to chose from its attributes on wich to dissolve.
NOTE that the
Input layer is an output of another geoprocessing algorithm, in this case Intersection. This takes two input layers and combines the attributes of them. In the Dissolve algorithm I need to select one (key)attribute of each of this input layers:
Now I would like to combine Intersection and Dissolve in the Graphical Modeler, sth. like
... but I struggle with the configuration of the Dissolve alg. Herein its GUI looks slightly different:
Intuitivly I would guess that the dropdown
Unique ID fields should by populated with the attribute names of the selected
Input layer in order to select the desired attributes to dissolve on, but it doesn't (wich is
clear at a second look, because during creating the model the input attributes are unknown since input layers are not yet selected)
Therefore I tried entering a comma separated list of the attribute names (prior known to me, here
name), but this is causing an error
Error executing algorithm Dissolve 'NoneType' object has no attribute 'split' See log for more details
...wich usually happens with unchecked
Dissolve all and no attributes provided.
Question: How to select the attributes to dissolve on when using Dissolve algorithm in Modeler with another algorithms output as input? Am I missing something or am I using this in an inappropriate way or is this worth raising an issue?