mrs_lib::ParamProvider Class Reference

Helper class for ParamLoader and DynparamMgr. More...

#include <param_provider.h>

Classes
struct	declare_options_t
	Struct of options when declaring a parameter to ROS. More...
struct	get_options_t
	Struct of options when getting a parameter from ROS. More...
struct	range_t
	Helper struct for a numeric range with named members to make the code a bit more readable. More...
struct	resolved_name_t
struct	set_options_t
	Struct of options when setting a parameter to ROS. More...

Public Member Functions
	ParamProvider (const std::shared_ptr< rclcpp::Node > &node, const bool use_rosparam=true)
	Main constructor.
bool	addYamlFile (const std::string &filepath)
	Add a YAML file to be parsed and used for loading parameters.
void	copyYamls (const ParamProvider &param_provider)
	Copy parsed YAMLs from another ParamProvider.
template<typename T >
bool	getParam (const std::string &param_name, T &value_out) const
	Gets the value of a parameter.
template<typename T >
bool	getParam (const resolved_name_t &resolved_name, T &value_out, const get_options_t< T > &opts={}) const
	Gets the value of a parameter.
template<typename T >
bool	setParam (const std::string &param_name, const T &value) const
	Sets the value of a parameter to ROS.
template<typename T >
bool	setParam (const resolved_name_t &resolved_name, const T &value, const set_options_t< T > &opts={}) const
	Sets the value of a parameter to ROS.
template<typename T >
bool	declareParam (const std::string &param_name) const
	Defines a parameter.
template<typename T >
bool	declareParam (const std::string &param_name, const T &default_value) const
	Defines a parameter with a default value.
template<typename T >
bool	declareParam (const resolved_name_t &resolved_name, const declare_options_t< T > &opts={}) const
	Defines a parameter with various options.
void	setPrefix (const std::string &prefix)
	Sets a prefix that will be applied to parameter names before subnode namespaces.
std::string	getPrefix () const
	Returns the current parameter name prefix.
resolved_name_t	resolveName (const std::string &param_name) const
	Returns the parameter name with prefixes and subnode namespaces.

Detailed Description

Helper class for ParamLoader and DynparamMgr.

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 std::shared_ptr< rclcpp::Node > &	node,
		const bool	use_rosparam = true
	)

Main constructor.

Parameters

nh	The parameters will be loaded from rosparam using this node handle.
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.

copyYamls()

void mrs_lib::ParamProvider::copyYamls

(

const ParamProvider &

param_provider

)

Copy parsed YAMLs from another ParamProvider.

Parameters

param_provider

The ParamProvider object to copy the YAMLs from.

declareParam() [1/3]

template<typename T >

bool mrs_lib::ParamProvider::declareParam	(	const resolved_name_t &	resolved_name,
		const declare_options_t< T > &	opts = {}
	)		const

Defines a parameter with various options.

This method declares the parameter in ROS with the behavior controlled by the options allowing to set a default value, valid value range (for numerical types), declare the parameter as reconfigurable, etc.

Parameters

param_name	Name of the parameter to be loaded.
opts	Options regarding declaring the parameter (see the declare_options_t<T> documentation).

Returns

true iff the parameter was successfully declared.

declareParam() [2/3]

template<typename T >

bool mrs_lib::ParamProvider::declareParam

(

const std::string &

param_name

)

const

Defines a parameter.

This method only declares the parameter in ROS.

Parameters

param_name

Name of the parameter to be loaded.

Returns

true iff the parameter was successfully declared.

declareParam() [3/3]

template<typename T >

bool mrs_lib::ParamProvider::declareParam	(	const std::string &	param_name,
		const T &	default_value
	)		const

Defines a parameter with a default value.

This method declares the parameter in ROS and sets the default value if there is no value in ROS.

Parameters

param_name	Name of the parameter to be loaded.
default_value	The default value to be set if there is no value of the parameter.

Returns

true iff the parameter was successfully declared.

getParam() [1/2]

template<typename T >

bool mrs_lib::ParamProvider::getParam	(	const resolved_name_t &	resolved_name,
		T &	value_out,
		const get_options_t< T > &	opts = {}
	)		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 declare it in ROS and attempt to load it 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.
opts	Options regarding getting and declaring the parameter (see the get_options_t<T> documentation).

Returns

true iff the parameter was successfully loaded.

getParam() [2/2]

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 declare it in ROS and attempt to load it 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

true iff the parameter was successfully loaded.

getPrefix()

std::string mrs_lib::ParamProvider::getPrefix

(

)

const

Returns the current parameter name prefix.

Returns

The current prefix to be applied to all parameter names.

resolveName()

ParamProvider::resolved_name_t mrs_lib::ParamProvider::resolveName

(

const std::string &

param_name

)

const

Returns the parameter name with prefixes and subnode namespaces.

Parameters

param_name

Name of the parameter.

Returns

name of the parameter with the appropriate prefixes and subnode namespaces applied.

setParam() [1/2]

template<typename T >

bool mrs_lib::ParamProvider::setParam	(	const resolved_name_t &	resolved_name,
		const T &	value,
		const set_options_t< T > &	opts = {}
	)		const

Sets the value of a parameter to ROS.

This method sets the parameter to ROS with the behavior controlled by the options allowing to set a default value, valid value range (for numerical types), declare the parameter as reconfigurable, etc.

Parameters

param_name	Name of the parameter to be set. Namespaces should be separated with a forward slash '/'.
value	The desired value of the parameter.
opts	Options regarding setting and declaring the parameter (see the set_options_t<T> documentation).

Returns

true iff the parameter was successfully set.

setParam() [2/2]

template<typename T >

bool mrs_lib::ParamProvider::setParam	(	const std::string &	param_name,
		const T &	value
	)		const

Sets the value of a parameter to ROS.

This method sets the parameter to ROS with the desired value.

Parameters

param_name	Name of the parameter to be set. Namespaces should be separated with a forward slash '/'.
value	The desired value of the parameter.

Returns

true iff the parameter was successfully set.

setPrefix()

void mrs_lib::ParamProvider::setPrefix

(

const std::string &

prefix

)

Sets a prefix that will be applied to parameter names before subnode namespaces.

The prefix will be applied as-is, so if you need to separate it from the parameter name e.g. using a forward slash '/', you must include it in the prefix.

Parameters

prefix

The prefix to be applied to all parameter names.

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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_provider/param_provider.cpp