CS - Library: Plugins

This library contains basic functions to load plugins and implementations of plugins providing data. The code is open-source (BSD License) and has been tested under Ubuntu 16.04 with ROS Kinetic. Please note that this project is part of ongoing research and that there will be changes in the future.

Structure

This project is divided up into the following subpackages:

• cslibs_plugins:
  This package contains utilities to load plugins.

• cslibs_plugins_data:
  This package contains plugins providing data. Currently implemented data types are 2D Laserscans, 3D Pointclouds and Odometry data.

Usage

Dependencies

The cslibs_plugins package does not have any internal dependencies.
The cslibs_plugins_data package depends on the following packages of our research group:

• cslibs_math
• cslibs_time
• cslibs_utility

Implementing Plugins

To implement a plugin, the easiest way is to inherit from cslibs_plugins::Plugin. Additionally, the following needs to be implemented:

• inline const static std::string Type()
  This function should return a unique identifier, e.g. class name including namespace of the plugin.

• inline void setup(...)
  This function is called by the cslibs_plugins::PluginFactory and sets up the plugin instance. This function may be implemented with any set of arguments which have to be passed to the cslibs_plugins::PluginLoader when the plugin shall be loaded.

• using Ptr = std::shared_ptr<plugin_t>;
  This typedef also needs to be overridden, where plugin_t is the newly implemented plugin type.

Loading Plugins

To load plugins, use an instance of cslibs_plugins::PluginLoader, whose constructor needs the name of the package the plugin that shall be loaded is located in, and a ros::NodeHandle:

cslibs_plugins::PluginLoader loader("package_name", nh);

Then, call the load function, which is templated regarding plugin type and the arguments of the setup function that is required to create the plugin. A single instance plugin of type plugin_t is loaded by:

loader.load<plugin_t, arg1_t, arg2_t, ...>(plugin, arg1, arg2, ...);

Multiple plugins of same type can be loaded concurrently by loading the plugins into a std::map<std::string, typename plugin_t::Ptr> plugin_map of type plugin_t:

loader.load<plugin_t, arg1_t, arg2_t, ...>(plugin_map, arg1, arg2, ...);

Examples

An exemplary abstract plugin definition can be found in cslibs_plugins_data.
The plugins themselves can be found in the src folder.
Loading and usage of plugins of this type can be found in muse_mcl_2d.

Contributing

Contribution guidelines for this project