bpy.ops.select_pattern() returns {FINISHED} even if object wasn't successfully selected #51310

New Issue

Henrik Berglund · 2017-04-24T17:19:30+02:00

Henrik Berglund commented

2017-04-24 17:19:30 +02:00

System Information
Win8.1, GTX1070

Blender Version
Broken:2.78c e92f235283

Short description of error
bpy.ops.select_pattern() returns {FINISHED} even if object wasn't successfully selected. For example if you're trying to select something on a layer that isn't visible. I use this in my export script. I've got the mesh and rig on different layers. Sometimes I forget to show the layer with the rig on and export only the mesh. When this is imported into UE4 using reimport strange things happen.

I think this operator should return an error if nothing was actually selected, in case for example you're trying to select something not visible. Or automatically showing the layer the object was on if nothing was selected at first.

Exact steps for others to reproduce the error

Add a cube.
Deselect cube.
Show only layer 2 by clicking on layer 2 without shift.
Type
bpy.ops.object.select_pattern(pattern="Cube")
in python console (assuming name of the cube was Cube).
Go to layer 1. It's not selected.

Expected: error when trying to select unselectable object.

**System Information** Win8.1, GTX1070 **Blender Version** Broken:2.78c e92f235283 **Short description of error** bpy.ops.select_pattern() returns {FINISHED} even if object wasn't successfully selected. For example if you're trying to select something on a layer that isn't visible. I use this in my export script. I've got the mesh and rig on different layers. Sometimes I forget to show the layer with the rig on and export only the mesh. When this is imported into UE4 using reimport strange things happen. I think this operator should return an error if nothing was actually selected, in case for example you're trying to select something not visible. Or automatically showing the layer the object was on if nothing was selected at first. **Exact steps for others to reproduce the error** 1. Add a cube. 2. Deselect cube. 3. Show only layer 2 by clicking on layer 2 without shift. 4. Type bpy.ops.object.select_pattern(pattern="Cube") in python console (assuming name of the cube was Cube). 5. Go to layer 1. It's not selected. Expected: error when trying to select unselectable object.

Henrik Berglund commented

2017-04-24 17:19:30 +02:00

Changed status to: 'Open'

Henrik Berglund commented

2017-04-24 17:19:30 +02:00

Added subscriber: @cyaoeu

Sergey Sharybin commented

2017-05-15 13:59:03 +02:00

Added subscriber: @Sergey

Sergey Sharybin commented

2017-05-15 13:59:03 +02:00

Changed status from 'Open' to: 'Archived'

Sergey Sharybin closed this issue

2017-05-15 13:59:03 +02:00

Sergey Sharybin self-assigned this 2017-05-15 13:59:03 +02:00

Sergey Sharybin commented

2017-05-15 13:59:03 +02:00

FINISHED means that operator execution finished, it does not denote anything whether operator changed something or not. So there is no bug here, since the operator did not fail or anything, it just didn't find anything selectable.

Henrik Berglund commented

2017-05-17 17:55:07 +02:00

I think it should fail (raise an error) if nothing was selected. If you expected something to be selected (which you probably do when running an operator called select_pattern) and nothing was selected it's an undesirable result.

I'm using select_pattern in my export scripts and if select_pattern didn't do anything in my script for some reason strange things happen. For example I was trying to select my rig, but it was on a hidden layer, so now I'm exporting my character without a rig. Thankfully the game engine I'm using complains when reimporting such an .fbx (in caps) so I don't mess anything up, but things like this shouldn't happen.

Now I'm checking if I actually selected something using select_pattern after that code row, and if I didn't I raise an exception, but doing this after you used select_pattern just feels strange. I would much rather use try: except:.

I think it should fail (raise an error) if nothing was selected. If you expected something to be selected (which you probably do when running an operator called select_pattern) and nothing was selected it's an undesirable result. I'm using select_pattern in my export scripts and if select_pattern didn't do anything in my script for some reason strange things happen. For example I was trying to select my rig, but it was on a hidden layer, so now I'm exporting my character without a rig. Thankfully the game engine I'm using complains when reimporting such an .fbx (in caps) so I don't mess anything up, but things like this shouldn't happen. Now I'm checking if I actually selected something using select_pattern after that code row, and if I didn't I raise an exception, but doing this after you used select_pattern just feels strange. I would much rather use try: except:.

Sergey Sharybin commented

2017-05-18 11:48:45 +02:00

Operator's return value is not only used for making decisions in the user's code, that return value is mainly used by the WindowManager to make decision how to unroll even handling after the operator's exec() finished, whether stuff needs to be put to undo buffer and so. Changing behavior of particular operator for a specific usecase is quite unlikely. You will really quickly run into conflict of interest of different script writers.

So just stick to the current design decision and live with that would be my suggestion.

Operator's return value is not only used for making decisions in the user's code, that return value is mainly used by the WindowManager to make decision how to unroll even handling after the operator's exec() finished, whether stuff needs to be put to undo buffer and so. Changing behavior of particular operator for a specific usecase is quite unlikely. You will really quickly run into conflict of interest of different script writers. So just stick to the current design decision and live with that would be my suggestion.

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bpy.ops.select_pattern() returns {FINISHED} even if object wasn't successfully selected #51310