[All] POC: ObjectFactory: Explicit components registration

[fredroy]

⚠️ Proof-of-concept ⚠️

• Task Get rid of singletons #3770

Main goal is to remove the ObjectFactory singleton (later) and the implicit registration of objects while loading dynamic libraries (plugins)

In this PR, the explicit registration is applied on components of Sofa.Component.StateContainer

The legacy RegisterObject mechanism is preserved and will warn the user at the compilation and at run-time.

EDIT:

• add tests about plugins non-registering/registering implicitly/registering explicitly
• add deprecations/warnings in RequiredPlugin
• add a function registerPlugin in PluginManager. This function is simply an alias for loadPlugin() because loadPlugin() does much more than just loading a plugin by itself. In an eventual future, PluginManager should be refactored in a way that loadPlugin calls registerPlugin()

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Reviewers will merge this pull-request only if

• it builds with SUCCESS for all platforms on the CI.
• it does not generate new warnings.
• it does not generate new unit test failures.
• it does not generate new scene test failures.
• it does not break API compatibility.
• it is more than 1 week old (or has fast-merge label).

[alxbilger]

Very interesting PR. I have some suggestions to make the code clearer and more expressive.

[alxbilger]

In the quest of removing the singletons, you could pass the pluginManager instance as a parameter

[fredroy]

[ci-build][with-all-tests]

[fredroy]

[ci-build][with-all-tests][force-full-build]

[fredroy]

[ci-build][with-all-tests][force-full-build]

[damienmarchal]

Maybe some ideas here: #2712

[fredroy]

[ci-build][with-all-tests][force-full-build]

[fredroy]

[ci-build][with-all-tests][force-full-build]

[alxbilger]

I am annoyed that a meta-module must call the "dynamic" functions (using strings) as if it does not have access to it statically.

[damienmarchal]

sofa::component::statecontainer::target = "Sofa.Component.StateContainer"

[alxbilger]

Instead, I suggest the following

Suggested change

	bool ObjectFactory::registerObjectsFromPlugin(const std::string& pluginName)
	bool ObjectFactory::registerObjectsFromPlugin(const helper::system::Plugin& plugin)

In Main.cpp , you would need to do:

    for (const auto& [_, plugin] : pluginManager.getPluginMap())
    {
        objectFactory->registerObjectsFromPlugin(plugin);
    }

[fredroy]

Actually it was what it was done at the beginning

sofa/Sofa/framework/Core/src/sofa/core/ObjectFactory.h

Line 198 in c36c145

bool registerObjectsFromPlugin(const sofa::helper::system::Plugin& plugin);

But how do use it in Sofa/Component/src/sofa/component/init.cpp ? You would still need to:

• get the pluginmanager (of course)
• find the plugin in the pluginMap (with its string ID)
• then calling registerObjectsFromPlugin on the retrieved pointer (after a nullptr check)

[alxbilger]

I understand. But this is what bothers me. I don't like that a meta-module needs the PluginManager (and even a Plugin object) to be able to interact with its own dependencies. If we use the PluginManager in Sofa.Component to load all the sub-modules, it's not even necessary to have them as a dependency of the module.

[hugtalbot]

For @sofa-framework/reviewers : this PR is now ready but it will have a massive impact on all the code base.

Any feedback is more than welcome. A compatibility layer is obviously implemented

We suggest to merge this PR but temporarily de-activating all the warnings (compilation-time and runtime). Another PR will start the cleaning within SOFA and its official plugins. When the main part will be done, warnings will be re-activated so that plugin authors can be informed.

[fredroy]

[ci-build][with-all-tests][force-full-build]