How do I get extensions in Evolution to work?

I’m trying (occasionally) to print emails from Evolution. I found
/usr/share/evolution/webkit/webview-print.css which gives me some formatting control; then I found /lib/evolution/modules/module-webkit-{editor,inspector}.so and /lib/evolution/web-extensions/webkit-editor/ on my machine, which look to modules/extensions to work with the webkit stuff, which would be nice. But none of it shows up under Edit → Plugins, and I can’t find it any where except in the file system.
How can I active, enable, whatever, those modules?

Evolution 3.366.5-0ubuntu1

What makes you think that these files have anything do with printing? Could you elaborate on your train of thoughts?

(Also note that your Evolution version is 43 months old, so if you plan to write custom code on your own I’d recommend to target recent software versions because future maintenance costs.)

only parts which can be enabled/disabled are shown in the GUI. Some
plugins are always enabled, as they are so called system plugins. The
modules are always loaded, but some of them can disable themselves.

As Andre said, I also do not see what you’d want to do with them and
why you think they are related to the printing.

If you’d like to extend Evolution, then you can check the second half
of the Extensions · Wiki · GNOME / evolution · GitLab .


The train is simple - print formatting is controlled by the webkit; these files, by name, inspect and edit the webkit, and one of them, by name, is an extension.
It is within reason to believe they might provide an easier way of editing the print css than using pluma as superuser and experimentation (changing colors to see what is controlled by what).
I have no interesting extending Evolution; after 60+ years in the industry, I’d like to be a User, as I have other things I’d like to be developing.

Okay. In that case, none of the binary files you mention in the description has any direct impact on the printing, it’s done elsewhere. The “inspector” is to be able to show a developer console of WebKit. It’s disabled by default and you cannot influence the printing with it anyway. The “editor”, well, there is the most of the editing bits, with “editing” as “message composer”. It’s split, because it’s required.

The CSS file defines the styles for printing. That’s the place where you can influence the formatting, in a sense of look & feel.

You did not explain what precisely you’d like to change in the printout. If just the look&feel, then okay, it’s the CSS file for (even not really expected to be changed by the users).

Hope it helps,