Overfall not showing after creating

[TriformMoritz]

I can create an overflow by editing directly the "overflow" table (which is very nice and the right way to do).
clicking on the nodes works.
But it is not showing up.
It is created in the table, but not in the graphical interface.

[cymed]

Did you fill out the topology? vw_tww_overflow is a point layer with a geometry calculator to create lines between fk_wastewater_node and fk_overflow_to

[TriformMoritz]

I do not know if the way I did create the overfall was right, but I think it was the most intuitive way and it should be like this (and I described it in QGEP back then):

• Click to edit the overfall layer.
• Click on node 1, click on node 2
• Enter the attributes in the formula.
• Done.
  So the way I did it was a little bit less intuitive, but worked
• Click to edit the overfall layer.
• Click on the first node. -> Formular opens
• Choose the two nodes.

If this was not the right way, then:

• We should make it the way I described if possible (user friendly).
• We should (in any way) not be allowed to create "not validated overfall"

[sjib]

Urs wrote how to do in the documentation: https://teksi.github.io/wastewater/user-guide/How-To/index.html#hydraulic-modeling-of-an-overflow-prank-weir-leapingweir-pump

[TriformMoritz]

So that is exactly what I did (so it seems fine to me as a procedure)! It is intuitive (it would be more intuitive, if you draw a line form node to node, but it works ok like it is).
But the overflow is still not showing.

[TriformMoritz]

Did you fill out the topology? vw_tww_overflow is a point layer with a geometry calculator to create lines between fk_wastewater_node and fk_overflow_to

And yes, you can see it in the image (fk_wasterwater_node are filled).

[urskaufmann]

Have you seen this hint in the docu (normally that's the reason it does not work):
The new overflow is drawn as dotted line with arrow. If the line does not appear: the line is defined with the QGIS geometry generator symbol. Control the formula of the geometry generator (layer properties/symbology, select the symbol), control first the name of the vw_wastewater_node layer. If this layer is renamed, the formula has to be changed with the new name (e.g. vw_Abwasserknoten)._

If I lock at your screenshot, you should write "noeud" instead of vw_wastewater_node in the fromula:

[cymed]

We should not use the layer name in the formula, but the layer id. We an also remove the numbers from the layer id and then it should work.
@TriformMoritz: Can you test whether it is fixed by opening the qgs file in a file editor and replacing vw_wastewater_node20150607121012062 with vw_wastewater_node?

[TriformMoritz]

Yes, it works! this should fix the problem.
Do we have this problem elsewhere?
And Urs, for the graphics, can we generate a curved line (https://gis.stackexchange.com/questions/215484/making-lines-curvy-in-qgis) ? the code will be probably more complex, but it would be much nicer. I would also give it a green color like in the wiki, but that is an extra.

[urskaufmann]

if I read on this link (making-lines-curvy...), you need another point between start and end to define a curve. I really dont know where to take this point.
If somebody wants to invest in this curve, please do. But I think there are many, many features that call for investments and that are much more essential for daily work than this curve. So on my side: 0 CHF.
Green color can be set in the symbol definition. I will change it in a next tww-project
Problem elsewhere: Yes, there are cases, where it can give problems with translated words. E.g. the list where you choose, if a new wastewater_structure is manhole, special_structure, infiltration_installation etc. This fills in the field "ws_type" and the tabs in Feature Attribute window are en-/disabled dependant of this field.

[TriformMoritz]

The point is calculated by the centroid of the line. The line is the line you created. So one could easily do it like this:

Make_Line(start_point($geometry),
translate(centroid(
Make_Line($geometry,geometry(get_feature('vw_wastewater_node20150607121012062','obj_id', fk_overflow_to )))), 0.1,0.1),
end_point(geometry(get_feature('vw_wastewater_node20150607121012062','obj_id', fk_overflow_to ))))

Still needs to adjust the 0.1 by getting the length of the line and adjust the center point arrow with some code, but it works.
Ok for the green color.

[cymed]

the visualisation of overflows is improved in #410

[sjib]

@cymed – Thanks a lot. Could you add a screenshot here?

[cymed]