Replace the previously-written manual calls to "new SomeClass(...)" with
their equivalent using
flightgear::addons::shared_ptr_traits<>::makeStrongRef(). This way, when
SomeClassRef is changed from SGSharedPtr<SomeClass> to
std::shared_ptr<SomeClass>, these calls will magically use
std::make_shared<SomeClass>(...) instead of the "new SomeClass(...)"
call.
(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
flightgear::addons::shared_ptr_traits allows one to easily switch for
instance from an SGSharedPtr<T> to an std::shared_ptr<T> for "all" uses
of a particular T, and automatically have std::make_shared<T>(...) used
instead of SGSharedPtr<T>(new T(...)) when creating a shared instance of
T. This is interesting because std::make_shared<T>() allocates all
needed memory as one block, whereas std::shared_ptr<T>(new T(args...))
would perform at least two allocations (one for the object T and one for
the control block of the shared pointer).
This is done via static methods (one for each kind of smart pointer):
shared_ptr_traits<SGSharedPtr<T>>::makeStrongRef()
shared_ptr_traits<std::shared_ptr<T>>::makeStrongRef()
that forward their arguments in the same way as std::make_shared<T>().
Normally, <regex> should be available and working in any compliant C++11
implementation, however at least g++ 4.8[1] lies about its C++11
compliance: its <regex> is utterly unusable, see [2] and [3] for
details.
This requires SimGear commit ab1e2d49abdf5b1aca9035a51d9d73d687f0eba7,
for the HAVE_WORKING_STD_REGEX preprocessor symbol.
[1] Which appears to be (precisely 4.8.5) the version shipped in
CentOS 7, and used on FlightGear's current Jenkins installation.
[2] https://stackoverflow.com/a/12665408/4756009
[3] https://sourceforge.net/p/flightgear/mailman/message/36170781/
Changes to test_AddonManagement.cxx:
- in testAddonVersionSuffix(), fgtest::initTestGlobals() was called
with the wrong test name (not used anyway, but might be in the
future);
- in testAddon():
* rename variable 'm' to 'addon' ('m' used to stand for the old
class name AddonMetadata);
* call fgtest::initTestGlobals() and fgtest::shutdownTestGlobals()
(not technically needed, but cleaner).
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/
- Parsing of the addon-metadata.xml file is now handled by a new static
method of Addon:
static Addon fromAddonDir(const SGPath& addonPath);
This method will be reusable to gather all add-on metadata from a set
of add-on directories (just call the method once per add-on). This
change also simplifies AddonManager::registerAddonMetadata().
- New supported fields:
authors
maintainers
license/{designation,file,url}
url/{home-page,download,support,code-repository}
tags
See
https://sourceforge.net/p/flightgear/fgdata/ci/next/tree/Docs/README.add-ons
for documentation on these fields.
Mailing-list discussion:
around https://sourceforge.net/p/flightgear/mailman/message/36155660/
Move the format-version node inside /meta. It's not compatible of
course, but since the stuff this is breaking is only 2 or 3 days old,
let's go for it for nicer code and file format.
Sorry if you had already written an addon-metadata.xml file of your
own. In this case, just replace:
<format-version type="int">1</format-version>
with:
<meta>
<file-type type="string">FlightGear add-on metadata</file-type>
<format-version type="int">1</format-version>
</meta>
This should fix the following compilation error and other similar ones:
converting to ‘std::tuple<flightgear::AddonVersionSuffixPrereleaseType,
int, bool, int>’ from initializer list would use explicit constructor
‘constexpr std::tuple< <template-parameter-1-1> >::tuple(_UElements&&
...)
According to <https://stackoverflow.com/a/32084829/4756009>, the change
wouldn't be needed in C++14 (and it built fine with my g++) but we use
C++11.
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/
