Represents a device parameter identified by index and subindex. More...

#include <common.h>

Public Member Functions
ParameterValue	getValue () const
	Retrieves the value of the parameter based on its data type. More...

template<typename T >
T	getValue () const
	Retrieves the parameter value from the `ParameterValue` variant as the specified type. More...

template<typename T >
std::optional< T >	tryGetValue () const
	Attempts to retrieve the parameter value from the `ParameterValue` variant as the specified type. More...

void	setValue (const ParameterValue &value)
	Sets the internal raw data representation from a given value. More...

template<typename T >
void	setValue (const T &value)
	Sets the parameter value using a strongly-typed input. More...

template<typename T >
bool	trySetValue (const T &value)
	Attempts to set the parameter value with a strongly-typed input. More...

bool	operator< (const Parameter &other) const
	Compares two Parameter objects for ordering. More...

bool	operator> (const Parameter &other) const
	Compares two Parameter objects for reverse ordering. More...

bool	operator== (const Parameter &other) const
	Checks if two Parameter objects are equal. More...

Static Public Member Functions
static void	to_json (nlohmann::json &j, const Parameter &p)
	Serializes a Parameter object to JSON. More...

static void	from_json (const nlohmann::json &j, Parameter &p)
	Deserializes a Parameter object from JSON. More...

Public Attributes
std::string	name
	Name of the parameter. More...

std::uint16_t	index
	Index of the parameter. More...

std::uint8_t	subindex
	Subindex of the parameter. More...

std::uint16_t	bitLength
	Bit length of the parameter. More...

int	byteLength
	Byte length of the parameter. More...

common::ObjectDataType	dataType
	The data type of the parameter, defined by `common::ObjectDataType`. More...

common::ObjectCode	code
	The object code for the parameter, defined by `common::ObjectCode`. More...

common::ObjectFlags	flags
	The object flags for the parameter, defined by `common::ObjectFlags`. More...

common::ObjectFlags	access
	The access flags for the parameter, defined by `common::ObjectFlags`. More...

std::vector< std::uint8_t >	data
	Holds raw data as a vector of uint8_t elements. More...

Detailed Description

Represents a device parameter identified by index and subindex.

The Parameter class models an object from a device's object dictionary, uniquely identified by a 16-bit index and an 8-bit subindex. These parameters typically appear in communication profiles such as CANopen or other embedded protocols that use structured configuration and runtime data.

Each Parameter holds metadata (name, data type, access rights, etc.) and stores its actual value as a byte array. The value can be safely interpreted and manipulated through variant-based and templated getter/setter functions, ensuring proper type handling.

The class also provides comparison operators for sorting or lookup based on index/subindex and supports JSON serialization for configuration export/import.

See also: ParameterValue, common::ObjectDataType, common::ObjectCode, common::ObjectFlags

Member Function Documentation

◆ from_json()

void common::Parameter::from_json	(	const nlohmann::json &	j,
		Parameter &	p
	)

static

Deserializes a Parameter object from JSON.

Parses the JSON object and populates the fields of the given Parameter instance. This assumes the JSON structure matches the format produced by to_json.

Parameters

j	The JSON object to deserialize.
p	The `Parameter` instance to populate.

◆ getValue() [1/2]

ParameterValue common::Parameter::getValue ( ) const

Retrieves the value of the parameter based on its data type.

This function extracts the raw data from the parameter's internal storage (data), converts it to the appropriate type based on the dataType, and returns it as a ParameterValue (which is a std::variant). The supported types include various integer, floating-point, and string types. For string types (VISIBLE_STRING, OCTET_STRING, UNICODE_STRING), the function ensures the string is null-terminated.

Returns

ParameterValue The value of the parameter as a ParameterValue (std::variant), which can be one of the following types:

bool for BOOLEAN
std::int8_t for INTEGER8
std::int16_t for INTEGER16
std::int32_t for INTEGER24 and INTEGER32
std::int64_t for INTEGER64
std::uint8_t for UNSIGNED8, PDO_MAPPING, IDENTITY, COMMAND_PAR, and RECORD
std::uint16_t for UNSIGNED16
std::uint32_t for UNSIGNED24 and UNSIGNED32
std::uint64_t for UNSIGNED64
float for REAL32
double for REAL64
std::string for VISIBLE_STRING, OCTET_STRING, and UNICODE_STRING

Exceptions

std::runtime_error If the dataType is not supported or is unknown.

◆ getValue() [2/2]

template<typename T >

T common::Parameter::getValue ( ) const

inline

Retrieves the parameter value from the ParameterValue variant as the specified type.

This function attempts to extract the stored parameter value from the ParameterValue variant, and if successful, it returns the value as the specified type T. If the type T does not match the type stored in the variant, a std::bad_variant_access exception is thrown.

Template Parameters

T	The type to retrieve from the `ParameterValue`. This type must match the type stored in the variant.

Returns: T The value of the parameter, cast to the type T.

Exceptions

std::bad_variant_access If the requested type T does not match the type stored in the ParameterValue.

◆ operator<()

bool common::Parameter::operator< ( const Parameter & other ) const

inline

Compares two Parameter objects for ordering.

The comparison is first done by the index property. If the indices are equal, the comparison is then done by the subindex property.

Parameters

other The other Parameter object to compare with.

Returns: True if the current object is less than the other object, false otherwise.

◆ operator==()

bool common::Parameter::operator== ( const Parameter & other ) const

inline

Checks if two Parameter objects are equal.

The equality check is performed by comparing the index and subindex properties. Both properties must be equal for the objects to be considered equal.

Parameters

other The other Parameter object to compare with.

Returns: True if both the index and subindex are equal, false otherwise.

◆ operator>()

bool common::Parameter::operator> ( const Parameter & other ) const

inline

Compares two Parameter objects for reverse ordering.

The comparison is first done by the index property. If the indices are equal, the comparison is then done by the subindex property.

Parameters

other The other Parameter object to compare with.

Returns: True if the current object is greater than the other object, false otherwise.

◆ setValue() [1/2]

void common::Parameter::setValue ( const ParameterValue & value )

Sets the internal raw data representation from a given value.

This function converts the provided value into a byte representation and stores it in the internal data vector, based on the current dataType. It supports all standard types defined in ObjectDataType.

If the value is a vector of bytes (std::vector<std::uint8_t>), it is directly copied into the internal buffer. Otherwise, the value is cast to the expected type based on dataType, converted to bytes, and stored.

For string types (VISIBLE_STRING, OCTET_STRING, UNICODE_STRING), the string content is copied and null-terminated if not already.

Parameters

value The value to store, wrapped in a ParameterValue variant.

Exceptions

std::bad_variant_access	If the value's type does not match the expected type.
std::runtime_error	If the data type is unsupported.

◆ setValue() [2/2]

template<typename T >

void common::Parameter::setValue ( const T & value )

inline

Sets the parameter value using a strongly-typed input.

This templated overload constructs a ParameterValue variant from the provided typed value and delegates to the main setValue function for byte-level storage based on the current ObjectDataType.

Template Parameters

T	The type of the input value. Must be compatible with ParameterValue.

Parameters

value The value to set.

Exceptions

std::bad_variant_access	If the type T is incompatible with the expected data type.
std::runtime_error	If the data type is unsupported during conversion.

◆ to_json()

void common::Parameter::to_json	(	nlohmann::json &	j,
		const Parameter &	p
	)

static

Serializes a Parameter object to JSON.

Converts the given Parameter object into a JSON representation, storing its fields such as name, index, data type, etc. Enums are cast to uint16_t to ensure compatibility with JSON output.

Parameters

j	The JSON object to store serialized data.
p	The `Parameter` instance to serialize.

◆ tryGetValue()

template<typename T >

std::optional< T > common::Parameter::tryGetValue ( ) const

inline

Attempts to retrieve the parameter value from the ParameterValue variant as the specified type.

This function tries to extract the stored parameter value from the ParameterValue variant and returns it as the specified type T in an std::optional<T>. If the type T does not match the type stored in the variant, the function returns std::nullopt.

Template Parameters

T	The type to retrieve from the `ParameterValue`. This type must match the type stored in the variant.

Returns: std::optional<T> An optional containing the value of type T if found; otherwise, std::nullopt.

◆ trySetValue()

template<typename T >

bool common::Parameter::trySetValue ( const T & value )

inline

Attempts to set the parameter value with a strongly-typed input.

This templated method checks whether the type of the input value matches the expected type based on the current ObjectDataType. If compatible, it sets the value; otherwise, it fails silently.

Template Parameters

T	The type of the input value to attempt setting.

Parameters

value The value to attempt to assign to the parameter.

Returns: true if the type matches the expected data type and the value was set; false otherwise.

Note: Supports raw byte input via std::vector<std::uint8_t> as a fallback.

Member Data Documentation

◆ access

common::ObjectFlags common::Parameter::access

The access flags for the parameter, defined by common::ObjectFlags.

◆ bitLength

std::uint16_t common::Parameter::bitLength

Bit length of the parameter.

◆ byteLength

int common::Parameter::byteLength

Byte length of the parameter.

◆ code

common::ObjectCode common::Parameter::code

The object code for the parameter, defined by common::ObjectCode.

◆ data

std::vector<std::uint8_t> common::Parameter::data

Holds raw data as a vector of uint8_t elements.

◆ dataType

common::ObjectDataType common::Parameter::dataType

The data type of the parameter, defined by common::ObjectDataType.

◆ flags

common::ObjectFlags common::Parameter::flags

The object flags for the parameter, defined by common::ObjectFlags.

◆ index

std::uint16_t common::Parameter::index

Index of the parameter.

◆ name

std::string common::Parameter::name

Name of the parameter.

◆ subindex

std::uint8_t common::Parameter::subindex

Subindex of the parameter.

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

libs/common/common.h
libs/common/common.cc

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Member Function Documentation

◆ from_json()

◆ getValue() [1/2]

◆ getValue() [2/2]

◆ operator<()

◆ operator==()

◆ operator>()

◆ setValue() [1/2]

◆ setValue() [2/2]

◆ to_json()

◆ tryGetValue()

◆ trySetValue()

Member Data Documentation

◆ access

◆ bitLength

◆ byteLength

◆ code

◆ data

◆ dataType

◆ flags

◆ index

◆ name

◆ subindex