Next Tutorial: Installation
Ignition Plugin is a component in Ignition Robotics, a set of libraries designed to rapidly develop robot and simulation applications. The main goal of the library is to simplify the process of registering plugin libraries and dynamically loading them at runtime. It is based on the following concepts:
- An "Interface" is a unit of functionality with a specified API that may be provided by a plugin. Interfaces may be defined using templates.
- A Plugin may provide multiple Interfaces, including different specializations of templated Interfaces.
- A "Library" may contain multiple plugins, which provides a convenient way to distribute different types of functionality in a single file.
The loader component can dynamically load plugin interfaces at runtime either by specifying a desired plugin or by listing plugins within a library file that provide a specific interface. There are highly performant ways to get direct access to a plugin interace that can be anticipated ahead of time by specializing the Plugin object at compile time. The loader also can use reference counting of plugin objects to unload libraries that are no longer in use.
The register component provides macros for registering templated and non-templated classes as plugins and/or interfaces. A plugin can be registered anywhere from within any translation unit. Interfaces can be queried by their C++ type, or they can be queried by name with a string.
The Ignition Physics Feature system provides a good example of the use of these unique aspects of ignition-plugin.