qgis_process is not showing algorithm providers installed via a python plugin

[janzandr]

Describe the bug

I installed and activated a python plugin that provides a processing algorithms (e.g. "Append Features to Layer" plugin).

When running "qgis_process plugins" from OSGeo4W shell, the new provider is not found:

I also tried to run the command from within QGIS Python Console, but that gives the same result:

[Gustry]

You should report to the plugin author and add the flag hasProcessingProvider in the metadata.txt and it should work.
https://docs.qgis.org/3.10/en/docs/pyqgis_developer_cookbook/plugins/plugins.html#plugin-metadata-table

And the initProcessing I think.
https://docs.qgis.org/3.10/en/docs/pyqgis_developer_cookbook/processing.html#updating-a-plugin

Reopen if it's not working.

[janzandr]

I added the hasProcessingProvider=True to metadata.txt, but that didn't solved the problem.

Here is a minimalistic plugin that implements a processing provider with one algorithm:

I installed the plugin via Install from ZIP and activated it, but qgis_process is still not listing it. Maybe I miss an important detail. Thanks for your support!

dummyplugin.zip

[Gustry]

You should follow the second link. You are missing the initProcessing. Can you try again ?

[janzandr]

I fixed that, but still not working. Here is the updated plugin:

dummyplugin.zip

[Gustry]

Reopening in the meantime.
Because it should work. I have already adapted plugins a few weeks ago.

[Gustry]

Put yes instead of True. It's working.
Like mentioned https://docs.qgis.org/3.10/en/docs/pyqgis_developer_cookbook/processing.html#updating-a-plugin
Agreed, it should work as well.

The table should be updated : https://docs.qgis.org/3.10/en/docs/pyqgis_developer_cookbook/plugins/plugins.html#plugin-metadata-table

[janzandr]

It worked, thanks a lot.

[gacarrillor]

You should report to the plugin author and add the flag hasProcessingProvider in the metadata.txt and it should work.
https://docs.qgis.org/3.10/en/docs/pyqgis_developer_cookbook/plugins/plugins.html#plugin-metadata-table

I'm with @Gustry here.
Not only fix your local copy of the plugin, but also contact the plugin author (for the example you gave, Append Features to Layer, it happens to be me :) ).

A PR will be much appreciated 👍

[janzandr]

I edited the metadata and the plugin and created PR.

[DelazJ]

Put yes instead of True.

@Gustry Maybe hasProcessingProvider should allow True/False (like the other parameters in the metadata file)? Unlike https://github.com/qgis/QGIS-Documentation/pull/3517/files#r264070345 I failed to have true or True work on a local plugin( ie being recognized by qgis_process -not aware of any other tool this parameter is meant to be used with). Or do we need to align the docs?

[Gustry]

The bug is still valid @gioman so I remove feedback.

Either we need to update to documentation, or indeed it would be better to upgrade QGIS core