The add-on framework now uses the following files in each add-on
directory:
- addon-config.xml (previously: config.xml)
- addon-main.nas (previously: main.nas)
This is consistent with the addon-metadata.xml file that is already part
of the interface between FG core and add-ons. The goal is to make it
clearer, when browsing an add-on directory, which files belong to the
"FG core <-> add-on" interface and which files belong to the add-on
proper. This will be beneficial also when more files are added to the
"FG core <-> add-on" interface, such as possibly addon-events.xml in the
future.
This change is incompatible, thus it is the right time to do *before*
2018.2.1 is out, especially considering that this upcoming release
already has incompatible changes in the add-on API, namely the
requirement of the addon-metadata.xml file and the type of the argument
passed to each add-on's main() function. We'll try harder not to break
compatibility in the add-on API once 2018.2.1 is out. For now, it is
still a good time to try to get the API as clean as possible.
The addons.Addon instance (ghost) is much more interesting than its base
path. The base path is immediately accessible from the addons.Addon
instance using its 'basePath' attribute. The addons.Addon instance
allows main() to easily access essentially all of the add-on metadata,
including the add-on identifier, which makes it possible to write
main.nas without hardcoding the add-on id at all.
This is an incompatible change of course, so better do it now than
later.
Also:
- use the namespace __addon[ADDON_ID]__ when loading an add-on's
main.nas file (previously, the namespace used was __addon[i]__ where
i is 0 for the first registered add-on, 1 for the second one, etc.);
- use logprint() instead of printlog(), because the former writes a
more helpful source file and line number for the log call in
fgfs.log (i.e., not always src/Scripting/NasalSys.cxx...);
- remove the listener once it has been fired;
- add documentation in Docs/README.add-ons.
