Python API : OBJECT_OT_convert can't be fully abstracted from context with override #93188

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Gorgious · 2021-11-18T14:55:59+01:00

Gorgious commented

2021-11-18 14:55:59 +01:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1660 SUPER/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 472.39

Blender Version
Broken: version: 2.93.5, branch: master, commit date: 2021-10-05 12:04, hash: a791bdabd0
It didn't work in latest Beta build either.
Worked: I don't think it ever worked otherwise ?

Short description of error
Overriding the context of an operator with a dictionary enables us to call them from pretty much anywhere in the code without having to make sure the context is correct (selected objects, active object, called from a particular editor, etc.)

However the OBJECT_OT_convert called with bpy.ops.object.convert operator still requires an active object to be selected to function with an override, which defeats the purpose of using an override.

It is explained quite thoroughly in this BSE Q&A https://blender.stackexchange.com/a/235048/86891

Exact steps for others to reproduce the error
Script to reproduce in an empty file :

import bpy

bpy.ops.curve.primitive_bezier_curve_add()

# Commenting these 2 lines removes the RuntimeError (context incorrect) on last line
bpy.context.active_object.select_set(False)
bpy.context.view_layer.objects.active = None

bpy.ops.object.convert({"selected_objects": bpy.data.objects}, target="MESH")

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: NVIDIA GeForce GTX 1660 SUPER/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 472.39 **Blender Version** Broken: version: 2.93.5, branch: master, commit date: 2021-10-05 12:04, hash: `a791bdabd0` It didn't work in latest Beta build either. Worked: I don't think it ever worked otherwise ? **Short description of error** Overriding the context of an operator with a dictionary enables us to call them from pretty much anywhere in the code without having to make sure the context is correct (selected objects, active object, called from a particular editor, etc.) However the `OBJECT_OT_convert` called with `bpy.ops.object.convert` operator still requires an active object to be selected to function with an override, which defeats the purpose of using an override. It is explained quite thoroughly in this BSE Q&A https://blender.stackexchange.com/a/235048/86891 **Exact steps for others to reproduce the error** Script to reproduce in an empty file : ``` import bpy bpy.ops.curve.primitive_bezier_curve_add() # Commenting these 2 lines removes the RuntimeError (context incorrect) on last line bpy.context.active_object.select_set(False) bpy.context.view_layer.objects.active = None bpy.ops.object.convert({"selected_objects": bpy.data.objects}, target="MESH") ```

👍 1

Gorgious commented

2021-11-18 14:55:59 +01:00

Added subscriber: @nathan.hild

Gorgious commented

2021-11-19 11:51:16 +01:00

I can add that bpy.ops.object.join has the same limitation :

This works :

bpy.context.view_layer.objects.active = next(o for o in bpy.data.objects if o.type == 'MESH')
for obj in bpy.data.objects:        
    obj.select_set(True)
bpy.ops.object.join()

This doesn't :

bpy.ops.object.join(
    {
        "selected_objects" : bpy.data.objects,
        "active_object": next(o for o in bpy.data.objects if o.type == 'MESH')
    }
)

Related thread on BSE https://blender.stackexchange.com/a/243663/86891

I can add that `bpy.ops.object.join` has the same limitation : This works : ``` bpy.context.view_layer.objects.active = next(o for o in bpy.data.objects if o.type == 'MESH') for obj in bpy.data.objects: obj.select_set(True) bpy.ops.object.join() ``` This doesn't : ``` bpy.ops.object.join( { "selected_objects" : bpy.data.objects, "active_object": next(o for o in bpy.data.objects if o.type == 'MESH') } ) ``` Related thread on BSE https://blender.stackexchange.com/a/243663/86891

Philipp Oeser commented

2021-11-19 12:50:38 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-11-19 12:50:38 +01:00

Join relies on selected_editable_objects, this works:

bpy.ops.object.join(
    {
        "selected_editable_objects" : bpy.data.objects,
        "active_object": next(o for o in bpy.data.objects if o.type == 'MESH')
    }
)

`Join` relies on `selected_editable_objects`, this works: ``` bpy.ops.object.join( { "selected_editable_objects" : bpy.data.objects, "active_object": next(o for o in bpy.data.objects if o.type == 'MESH') } ) ```

Gorgious commented

2021-11-19 13:08:48 +01:00

Oh, my bad, thanks for the clarification. :)

Is there a similar context override that I've missed for Convert ?

Oh, my bad, thanks for the clarification. :) Is there a similar context override that I've missed for `Convert` ?

Philipp Oeser commented

2021-11-19 13:38:52 +01:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Philipp Oeser commented

2021-11-19 13:38:52 +01:00

Added subscriber: @dr.sybren

Philipp Oeser commented

2021-11-19 13:38:52 +01:00

Regarding the Convert operator: I think it's true, this cannot be fully abstracted with override context.

Instead of relying on Object only, this operator takes into account the Base (which is kind of an abstraction of Object that can handle stuff like selection or visibilty in different viewlayers).
Doing this is useful, because it can then handle the needed stuff on the Base & new Base properly when a new converted object is created.
And afaict, python does not have access to this Base "stuff".
I dont actually think it is absolutely mandatory that this operator works this way (I think it could first rely on Object only -- and only later handle the Base as well -- which could make the whole usecase of this report possible), however, I am unsure if this could be called a bug (dont think it is, it is probably just a limitation of this particular operator -- and there are workarounds using python differently here).

Since @dr.sybren would probably know this in more depth (and would know if there is some sort of guideline or "promised support" of overriding context): could this be called a bug?

Regarding the `Convert` operator: I think it's true, this cannot be fully abstracted with override context. Instead of relying on `Object` only, this operator takes into account the `Base` (which is kind of an abstraction of `Object` that can handle stuff like selection or visibilty in different viewlayers). Doing this is useful, because it can then handle the needed stuff on the Base & new Base properly when a new converted object is created. And afaict, python does not have access to this `Base` "stuff". I dont actually think it is absolutely mandatory that this operator works this way (I think it could first rely on `Object` only -- and only later handle the `Base` as well -- which could make the whole usecase of this report possible), however, I am unsure if this could be called a bug (dont think it is, it is probably just a limitation of this particular operator -- and there are workarounds using python differently here). Since @dr.sybren would probably know this in more depth (and would know if there is some sort of guideline or "promised support" of overriding context): could this be called a bug?

Philipp Oeser removed the

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Python API : OBJECT_OT_convert can't be fully abstracted from context with override #93188