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Maniphest T51011

bpy.ops.action.new() does nothing when invoked from script
Closed, ResolvedPublicBUG
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Description

System Information
Win 8.1, GTX1070

Blender Version
Broken: 2.78c e92f235283

Short description of error
bpy.ops.action.new() does nothing when invoked from a script. Maybe you're not supposed to but then why is it listed in the API?

Exact steps for others to reproduce the error
Create some object. Create an action in the action editor. Open a text editor and write

import bpy
bpy.context.area.type = 'DOPESHEET_EDITOR'
bpy.context.space_data.mode = 'ACTION'
bpy.ops.action.new()
bpy.context.area.type = 'TEXT_EDITOR'

and click run script. Nothing happens. I would expect the same thing happening that happens when you click the add action button in the UI: a new action is created with identical keyframes and then selected in the action editor list automatically.

edit: changed from Addons to BF Blender tag.

Revisions and Commits

rB Blender
rB24ebed4d841e Fix T51011: bpy.ops.action.new does nothing when invoked from script

Related Objects

Event Timeline

Henrik Berglund (cyaoeu) created this task.Mar 20 2017, 5:52 PM
Brendon Murphy (meta-androcto) changed the task status from Unknown Status to Archived.Apr 7 2017, 1:20 AM
Brendon Murphy (meta-androcto) claimed this task.
Brendon Murphy (meta-androcto) added a subscriber: Brendon Murphy (meta-androcto).

hi,
to test:
On default cube, insert keyfame 0, move timeline to 100, scale & move the cube, insert keyframe.
run this:

import bpy
bpy.context.area.type = 'DOPESHEET_EDITOR'
bpy.context.space_data.mode = 'ACTION'

A new action is created as expected.

Closing as invalid.

Henrik Berglund (cyaoeu) added a comment.Apr 7 2017, 2:22 AM

What? You created the action when inserting the keyframes...

But I guess I can be more clear about what's wrong.

  1. Default cube, insert keyframe on 0, move to 100, insert another keyframe.
  2. Open the action editor and confirm that an action called CubeAction was created when inserting the keyframes.
  3. Click the + sign in the action editor to create a new action. A new action called CubeAction.001 is created.
  4. Now in the text editor, paste the code I wrote at the top and run it. No new action is created. This is a bug, what I expect is that a new action called CubeAction.002 is created, just like when pressing the + button in the action editor.
Brendon Murphy (meta-androcto) added a comment.Apr 7 2017, 2:44 AM

hi, ok, getting it now.
I think probably this is a more a python support issue, I see now that indeed you are correct & your code does fail.
have you looked at blender stackexchange for similar questions?
it would seem to be that to do this by py you need to set a keyframe first?
also unsure if contexts for this operator are correct or need to be set.

Henrik Berglund (cyaoeu) added a comment.Apr 7 2017, 3:00 AM

I saw in the Blenderartist forums that someone had the same problem, the advice that was given was to "not use the operator", which seems like a bad workaround if you really want the same behavior. I really like the + button operator, it creates a new action with the same name+.001, selects it in the action editor automatically and even copies all of the keyframes from the previous animation. Basically great for when you're making for example looping variations. The only problem with it is that it doesn't work in scripts right now.

I think the context for the operator should be correct, if you remove the bpy.context.area.type = 'DOPESHEET_EDITOR'
bpy.context.space_data.mode = 'ACTION' stuff you get a polling error. But if you execute those commands you don't get an error. To me this means that it should be correct. Nothing happens though which is a bit strange. If you're not supposed to be able to use the operator in scripts I would expect an error explaining why it can't be used. But if it's really a bug that it doesn't do anything right now I would be happy if it could be fixed.

Brendon Murphy (meta-androcto) changed the task status from Archived to Unknown Status.Apr 7 2017, 8:26 AM

reopening for more investigation

Brendon Murphy (meta-androcto) lowered the priority of this task from 90 to Normal.Apr 7 2017, 8:26 AM
Henrik Berglund (cyaoeu) updated the task description. (Show Details)Apr 24 2017, 5:12 PM
Henrik Berglund (cyaoeu) edited projects, added BF Blender; removed Add-ons (Community).
Dalai Felinto (dfelinto) removed Brendon Murphy (meta-androcto) as the assignee of this task.Dec 23 2019, 4:36 PM
Dalai Felinto (dfelinto) added a project: Tracker Curfew.
Germano Cavalcante (mano-wii) edited projects, added Python API; removed Tracker Curfew.Jan 23 2020, 2:34 PM
Germano Cavalcante (mano-wii) changed the subtype of this task from "Report" to "Bug".
Germano Cavalcante (mano-wii) added a subscriber: Germano Cavalcante (mano-wii).

Analyzing the bpy.ops.action.new's code, I could see that it only works when it is called from a button.
This is because it reads the button context and gets the current action through it.
This is a bad assumption, as this operator is totally useless if called in python.

Germano Cavalcante (mano-wii) closed this task as Resolved by committing rB24ebed4d841e: Fix T51011: bpy.ops.action.new does nothing when invoked from script.Jan 23 2020, 2:45 PM
Germano Cavalcante (mano-wii) claimed this task.
Germano Cavalcante (mano-wii) added a commit: rB24ebed4d841e: Fix T51011: bpy.ops.action.new does nothing when invoked from script.