Styling and hiding parts of the network in QGIS
What A user wants to be able to toggle the visibility of links showing demand/return_flow on/off so the user doesn't get lost in all edges.
Why Demand/supply often represent (piped)systems that are not modelled explicitly. They will cross the actual water system that is being modelled explicitly. The user may get lost in a web of edges representing supply and return_flow
How
Suggest to add a demand edge_type, or something similar, that the user can switch off in QGIS, just as the user can toggle control-type links on and off
The edge_type is primarily something we need to distinguish in the core. Besides this our default style uses this a a categorized symbology to give them a separate color.
It might be worth thinking about nice ways to control visibility by for instance looking at a column in the data model, or adding toggles. Though I think the requirements for this are different per model, and it probably won't be a priority soon. Also these is value to relying on QGIS as much as possible for these kinds of things.
For instance you can switch from a categorized to a rule-based symbology, and look at the from_node_type or to_node_type:
With #1713 you can now customize the style in QGIS as you wish, and it will save this in the model database. Let us know if that is sufficient.
One related issue that would improve this further, that you brought up before, is tracked in https://github.com/Deltares/Ribasim/issues/1754.