Leveraging the help_url in a gramplet

[emyoulation]

In the PlaceCleanup addon gramplet, @prculley implements (2 layers of) Help and “Set Preferences” buttons. The Gramplet does not use the help-url from the Gramps Plugin Registration (.gpr.py) file. It uses a hard-coded URL instead.

@jmichault adapts this addon to make a Lokpurigado version that is more appropriate for France. (It uses OpenStreetMap instead of geonames. Takes INSEE codes instead of the zip codes.)

But the adaptation strips out the hard-coded bit but not the 2 layers of custom Help buttons… one in the docked gramplet nor the one in the spawned Preferences dialog.

How could the gramplet be changed to make the following not hard-coded but self-adapting … by using the help_url for the WIKI_PAGE and (help_url + "#Preferences") for the PREFS_WIKI ?

gramps-project/addons-source/blob/dbc6718f7ccdd78d05ac082cefbefab193680c92/PlaceCleanup/placecleanup.py#L85-L88

And, is there way the custom Help button could be suppressed in the undocked gramplet.

Also, the Preferences does not use the View → Configuration GUI. It spawns its own GUI dialog. but that is a separate issue.

[emyoulation]

In Update help url registrations for built-in reports and tools - PR#1648, @Nick-Hall Added support for full http:// and https:// urls.

Is it reasonable to add support for ./ ? Adding a ‘relative’ path — to where the .gpr.py (or the module) file lives — would allow documentation to be bundled with an addon in a predictable way. (Local documentation is particularly handy in the beta cycle for an addon.)

In addition, a media\capture.png (or capture.webp or any other picture format) subfolder/filename be made a standard recognized by Gramps thumbnailers. So that a representative thumbnail image could be shown by the various dialogs in Gramps,