Cannot execute plugin from batch conversion job JSON

[deltark]

Issue type

Other type of issue

Description with steps to reproduce

• Install a plugin that modifies scores, such as Add Metronome Part
• Create job.json file with input, plugin call, and output:

[
    {
      "in": "score.mscz",
      "plugin": "path/to/addMetronomePart.qml",
      "out": "modified_score.mscz"
    }
]

• In CLI, run musescore4portable -j job.json
• Output file is produced without desired modification from plugin (for addMetronomePart it is supposed to add a Wood Blocks part to stand in for the metronome)

Supporting files, videos and screenshots

Output file does not have Wood Blocks part.

What is the latest version of MuseScore Studio where this issue is present?

4.4

Regression

Yes, this used to work in MuseScore 3.x and now is broken

Operating system

Kubuntu 22.04

Additional context

No response

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible

[ephemer]

Hi @igorkorsukov, I wanted to ask whether adding plugins back to the Musescore 4 CLI is something the team is considering?

Essentially: is this something that isn't happening due to a lack of resources, or because it's deliberately been removed for reasons we can't foresee?

[cbjeukendrup]

The removal of this option was not a deliberate decision; indeed, we just haven't got round to implementing it again yet.
However, it might be worth noting that the --extension command line option also seems to affect batch conversions, so if all tasks in your batch file need the same plugin treatment, then you can use that.

[ephemer]

@cbjeukendrup is the --extension option only available in nightlies perhaps?

/Applications/MuseScore\ 4.app/Contents/MacOS/mscore --extension test
MuseScore4: Unknown option 'extension'.

We are very flexible whether we use the plugin API, extensions, or any other kind of automation. But at the moment nothing is possible from what I can see.

I can see a bunch of historical work about enabling extensions, but I couldn't find any more information about it including documentation, conceptual overview, or any UI related to it. Any links or other discussions would be a great help 🙏🏼

⚠️ edit: I just downloaded the 4.5.0 nightly and do see the --extension option. I will look further into it

[cbjeukendrup]

The situation might be that it was called --plugin up to v4.4, and was renamed to --extension recently. If so, we should probably keep accepting --plugin for compatibility.

[ephemer]

FYI neither —plugin nor —extension works in 4.4.

From my understanding neither exists in any 4.x version until 4.5 where —extension is introduced.

Edit: forgive the lack of double hyphens, I’m writing on the phone, which „autocorrects“ them.

[ephemer]

Hi @cbjeukendrup, I managed to get my existing plugin working in the extension API. The DevTools->Extensions section in the nightly build lists it as muse://extensions/v1/dump/dump_debuginfo.qml – clicking that in the list there does what it should.

But I can't get it to run as an extension from the CLI. It appears the --extension argument just does nothing at all. I also looked into Resources/extensions/batch_example which appears to show a way to run a job and have the extension's action run on each job item. But I can't get it to work – the command line doesn't print any error and nothing happens at all (also the "out" listed in the job is not produced)

Could you point me to a working example or any docs or even relevant source code?