PluginClassLoader< BaseT > Class Template Reference

Class for loading plugin resources registered according to the conventions defined by the pluginlib package. More...

#include <auto_apms_util/resource.hpp>

Public Member Functions
	PluginClassLoader (const std::string &base_package, const std::string &base_class, const std::set< std::string > &exclude_packages={})
	Standard PluginClassLoader constructor.
std::map< std::string, std::string >	getClassPackageMap ()
	Retrieve a map that contains information about which package a plugin class belongs to.

Static Public Member Functions
static PluginClassLoader	makeUnambiguousPluginClassLoader (const std::string &base_package, const std::string &base_class, const std::set< std::string > &exclude_packages={}, const std::map< std::string, std::string > &reserved_names={})
	Parse all associated plugin manifest files registered with the ament resource index and instantiate a PluginClassLoader.

Detailed Description

template<typename BaseT>
class auto_apms_util::PluginClassLoader< BaseT >

Class for loading plugin resources registered according to the conventions defined by the pluginlib package.

Template Parameters

BaseT

Base class of the plugin.

For a class to be discoverable, you must call the C++ macro PLUGINLIB_EXPORT_CLASS and provide the arguments according to your definitions. AutoAPMS provides convenient wrappers that encapsulate this macro.

You must also make sure, that you create a plugins.xml file, add the corresponding entries and export it in the CMakeLists.txt of your ROS 2 package. Again, AutoAPMS provides convenient wrapper macros for specific use cases.

If you did all the above and want to instantiate a plugin class, you must call e.g. createSharedInstance and provide a lookup name for the plugin formatted like this:

• <namespace>::<class_name>

Token Name	Description
<namespace>	Full C++ namespace that the class <class_name> can be found in. It can be flat foo or arbitrarily nested foo::bar (individual levels must be separated by ::).
<class_name>	Name you specified when declaring the plugin class using the class keyword in C++. If the class takes template arguments, you must provide it using the MyClass<T> syntax as you would in the source code.

Definition at line 115 of file resource.hpp.

Constructor & Destructor Documentation

PluginClassLoader()

template<typename BaseT>

PluginClassLoader ( const std::string & base_package, const std::string & base_class, const std::set< std::string > & exclude_packages = {} )

inline

Standard PluginClassLoader constructor.

Alternatively, if you want to verify that only unique class names are loaded, have a look at PluginClassLoader::makeUnambiguousPluginClassLoader.

Parameters

base_package	Name of the package containing the base_class. Will throw an error if it is not installed.
base_class	Fully qualified name of the base class that the class loader will use for determining which classes listed in a plugins.xml file are associated with this instance.
exclude_packages	Packages to exclude when searching for plugins.

Exceptions

ament_index_cpp::PackageNotFoundError	if base_package is not installed.
auto_apms_util::exceptions::ResourceError	if no plugins of type base_class were found.

Definition at line 176 of file resource.hpp.

Member Function Documentation

makeUnambiguousPluginClassLoader()

template<typename BaseT>

PluginClassLoader< BaseT > makeUnambiguousPluginClassLoader ( const std::string & base_package, const std::string & base_class, const std::set< std::string > & exclude_packages = {}, const std::map< std::string, std::string > & reserved_names = {} )

inlinestatic

Parse all associated plugin manifest files registered with the ament resource index and instantiate a PluginClassLoader.

This factory method additionally performs an ambiguity check. This means that it verifies that only unique class names are being registered by the searched packages. Using the standard constructor, previously registered classes are being overriden if the same class name is being parsed again. Therefore, this method offers the preferred way of instantiating a PluginClassLoader.

Template Parameters

LoaderT

Type of the plugin class loader.

Parameters

base_package	Name of the package containing the base_class. Will throw an error if it is not installed.
base_class	Fully qualified name of the base class that the class loader will use for determining which classes listed in a plugins.xml file are associated with this instance.
exclude_packages	Packages to exclude when searching for plugins.
reserved_names	Map of reserved class names and the package name that makes the reservation. If any of these class names are found, an error is being raised (Used internally during build time when installed resources aren't available yet).

Exceptions

ament_index_cpp::PackageNotFoundError	if base_package is not installed.
auto_apms_util::exceptions::ResourceError	if no plugins of type base_class were found.
auto_apms_util::exceptions::ResourceError	if multiple packages register a resource using the same class name (or a name in reserved_names is found).

Definition at line 183 of file resource.hpp.

getClassPackageMap()

template<typename BaseT>

std::map< std::string, std::string > getClassPackageMap ( )

inline

Retrieve a map that contains information about which package a plugin class belongs to.

Returns

Mapping according to {class_name: package_name}.

Definition at line 222 of file resource.hpp.

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The documentation for this class was generated from the following file:

• auto_apms_util/include/auto_apms_util/resource.hpp