New methods Addon::createStorageDir() and Addon::getStoragePath() with
corresponding Nasal bindings in the addons.Addon ghost:
createStorageDir() method (returns the dir, doesn't fail if it already
exists)
storagePath read-only attribute to get the dir
The directory reserved for each add-on is
$FG_HOME/Export/Addons/ADDON_ID, but please use the above methods (or
the corresponding C++ ones) to avoid hardcoding such paths in your code.
Also create directory $FG_HOME/Export/Addons in fgInitConfig() as a way
of reserving the namespace, in order to prevent future failures in case
someone would have the strange idea to create it as a file...
If an add-on has a file named addon-menubar-items.xml in its base
directory, load it and add its items to the FG menubar.
Logically, fgStartNewReset() should call
flightgear::addons::AddonManager::instance()->addAddonMenusToFGMenubar()
in order to re-add the items, however doing so would cause the
add-on-specific menus to be added one more time on every reset, because
for some reason, commit 45ea8b5daa added
the PRESERVE attribute to /sim/menubar (apparently to preserve the state
of menu entries upon reset?).
Note: the addon-menubar-items.xml files are reloaded during reset,
however the menu bar doesn't reflect this, since adding the
reloaded items to the menu bar in fgStartNewReset() would cause
the add-on-specific menus to appear several times in the menu bar,
as explained above.
This method takes a string such as "this/is/a/relative/path" and returns
"[addon=ADDON_ID]this/is/a/relative/path", substituting the add-on
identifier for ADDON_ID.
This way, add-on authors don't even have to know the special syntax
'[addon=ADDON_ID]relative/path' used for add-on-specific resource paths,
and don't need to hardcode their add-on identifier inside each such path
either.
A resource can be specified with the syntax:
[addon=ADDON_ID]relative/path
Such a resource corresponds to the file $addon_base_path/relative/path
for the specific add-on whose identifier is ADDON_ID.
If the particular add-on isn't registered, looking up such a resource
throws sg_exception.
(everything described here lives in the namespace flightgear::addons)
New classes: Author, Maintainer, and Contact. Author and Maintainer
derive from Contact. For each contact, the following can be defined in
addon-metadata.xml: name, email, and url. See [1] for details about the
syntax and usage policy. Nasal bindings have been updated accordingly,
there are three new ghosts: addons.Contact, addons.Author and
addons.Maintainer.
The enum class UrlType has two new members: author and maintainer. The
Addon::getUrls() method has a new signature:
std::multimap<UrlType, QualifiedUrl> getUrls() const;
because non-empty 'url' fields for authors and maintainers contribute to
the result, and there can be an arbitrary number of authors and an
arbitrary number of maintainers defined for a given add-on---therefore,
std::map can't be used anymore.
Finally, QualifiedUrl has a new field (detail) which stores the author
name (resp. maintainer name) when the QualifiedUrl type is
UrlType::author (resp. UrlType::maintainer). Currently, this 'detail'
field is not used for other URL types, but this could be changed if
desired.
[1] https://sourceforge.net/p/flightgear/fgdata/ci/next/tree/Docs/README.add-ons
QualifiedUrl is essentially a pair containing an enum value
(addons::UrlType::homePage, addons::UrlType::download, etc.) and an
std::string for the URL per se, with adequate getters and setters.
Addon::getUrls() is for people who wish to process all non-empty URLs
occurring as part of the add-on metadata in batch.
Mailing-list discussion:
https://sourceforge.net/p/flightgear/mailman/message/36159711/
This commit adds C++ classes for add-on management, most notably
AddonManager, Addon and AddonVersion. The AddonManager is used to
register add-ons. It relies on an std::map<std::string, AddonRef> to
hold the metadata of each registered add-on (keys of the std::map are
add-on identifiers, and AddonRef is currently SGSharedPtr<Addon>).
Accessor methods are available for:
- retrieving the list of registered or loaded add-ons (terminology
explained in $FG_ROOT/Docs/README.add-ons);
- checking if a particular add-on has already been registered or
loaded;
- for each add-on, obtaining an Addon instance which can be queried
for its name, id, version, base path, the minimum and maximum
FlightGear versions it requires, its base node in the Property Tree,
its order in the load sequence, short and long description strings,
home page, etc.
The most important metadata is made accessible in the Property Tree
under /addons/by-id/<addon-id> and the property
/addons/by-id/<addon-id>/loaded can be checked or listened to, in
order to determine when a particular add-on is loaded. There is also a
Nasal interface to access add-on metadata in a convenient way.
In order to provide this metadata, each add-on must from now on have in
its base directory a file called 'addon-metadata.xml'.
All this is documented in much more detail in
$FG_ROOT/Docs/README.add-ons.
Mailing-list discussion:
https://sourceforge.net/p/flightgear/mailman/message/36146017/
