mrs_lib::ParamProvider Class Reference

Helper class for ParamLoader. More...

#include <param_provider.h>

Public Member Functions
	ParamProvider (const ros::NodeHandle &nh, std::string node_name, const bool use_rosparam=true)
	Main constructor. More...
bool	addYamlFile (const std::string &filepath)
	Add a YAML file to be parsed and used for loading parameters. More...
template<typename T >
bool	getParam (const std::string &param_name, T &value_out) const
	Gets the value of a parameter. More...
bool	getParam (const std::string &param_name, XmlRpc::XmlRpcValue &value_out) const
	Specialization of getParam() for the XmlRpcValue type. More...

Detailed Description

Helper class for ParamLoader.

This class abstracts away loading of parameters from ROS parameter server and directly from YAML files ("static" parameters). The user can specify a number of YAML files that will be parsed and when a parameter value is requested, these are checked first before attempting to load the parameter from the ROS server (which can be slow). The YAML files are searched in FIFO order and when a matching name is found in a file, its value is returned.

Constructor & Destructor Documentation

ParamProvider()

mrs_lib::ParamProvider::ParamProvider	(	const ros::NodeHandle &	nh,
		std::string	node_name,
		const bool	use_rosparam = true
	)

Main constructor.

Parameters

nh	The parameters will be loaded from rosparam using this node handle.
node_name	Optional node name used when printing the loaded values or loading errors.
use_rosparam	If true, parameters that weren't found in the YAML files will be attempted to be loaded from ROS.

Member Function Documentation

addYamlFile()

bool mrs_lib::ParamProvider::addYamlFile

(

const std::string &

filepath

)

Add a YAML file to be parsed and used for loading parameters.

The first file added will be the first file searched for a parameter when using getParam().

Parameters

filepath

Path to the YAML file.

getParam() [1/2]

template<typename T >

bool mrs_lib::ParamProvider::getParam	(	const std::string &	param_name,
		T &	value_out
	)		const

Gets the value of a parameter.

Firstly, the parameter is attempted to be loaded from the YAML files added by the addYamlFile() method in the same order that they were added. If the parameter is not found in any YAML file, and the use_rosparam flag of the constructor is true, the ParamProvider will attempt to load it from the ROS parameter server.

Parameters

param_name	Name of the parameter to be loaded. Namespaces should be separated with a forward slash '/'.
value_out	Output argument that will hold the value of the loaded parameter, if successfull. Not modified otherwise.

Returns

Returns true iff the parameter was successfully loaded.

getParam() [2/2]

bool mrs_lib::ParamProvider::getParam	(	const std::string &	param_name,
		XmlRpc::XmlRpcValue &	value_out
	)		const

Specialization of getParam() for the XmlRpcValue type.

The XmlRpc::XmlRpcValue can be useful for manual parsing of more complex types.

Warning

XmlRpc::XmlRpcValue parameters cannot be loaded from a YAML file - only from ROS!

Parameters

param_name	Name of the parameter to be loaded. Namespaces should be separated with a forward slash '/'.
value_out	Output argument that will hold the value of the loaded parameter, if successfull. Not modified otherwise.

Returns

Returns true iff the parameter was successfully loaded.

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

• include/mrs_lib/param_provider.h
• include/mrs_lib/impl/param_provider.hpp
• src/param_loader/param_provider.cpp