ParameterTable Class Reference

A utility class for managing JSON-based data tables. More...

Inheritance diagram for ParameterTable:

Detailed Description

Interface for handling and querying data in the form of a property tree of the boost library. It facilitates the extraction of specific parameters from loaded JSON files while also supporting units and scales.

Its main use is as base class of OMSimInputData, but you may use it as needed (see Minimal example).

Minimal example

ParameterTable lTable; // Create an instance of the table
lTable.appendAndReturnTree("path/to/file.json"); // Load a JSON file into the table. The key of this file (in the following "SomeKey") is contained within the file under the variable "jName"
G4double lValue = lTable.getValue<G4double>("SomeKey", "SomeParameter"); // Fetch a specific value using its key and parameter name
 
// Parsing array content from a JSON subtree into a vector using parseKeyContentToVector
std::vector<G4double> lVector;
pt::ptree lSubtree = lTable.getJSONTree("SomeKey"); // Retrieving the subtree of the file
lTable.parseKeyContentToVector(lVector, lSubtree, "keyOfArray", 1.0, false); // parsing array into vector

Public Member Functions
template<typename T >
T	getValue (G4String pKey, G4String pParameter)
	Fetches a value from the table based on a key and parameter.
G4bool	checkIfTreeNameInTable (G4String pKey)
	Checks if a key exists within the table.
G4bool	checkIfKeyInTree (G4String p_treeName, G4String p_key)
	Checks if a specific key exists in a given JSON tree.
G4double	getValueWithUnit (G4String pKey, G4String pParameter)
	Fetches the value associated with a given key and parameter.
pt::ptree	appendAndReturnTree (G4String pFileName)
pt::ptree	getJSONTree (G4String pKey)
template<typename T >
void	parseKeyContentToVector (std::vector< T > &pVector, pt::ptree pTree, std::basic_string< char > pKey, G4double pScaling, bool pInverse)
	Parses the content of a JSON subtree into a vector, scaling values if necessary.
template<typename T >
void	parseKeyContentToVector (std::vector< T > &pVector, std::basic_string< char > p_MapKey, std::basic_string< char > pKey, G4double pScaling, bool pInverse)
	Parses the content of a JSON subtree into a vector, scaling values if necessary.

Private Attributes
std::map< G4String, boost::property_tree::ptree >	m_table
	A table mapping keys to property trees.
std::map< G4String, G4String >	m_keyToFileName
	A table mapping keys to original file name.

Member Function Documentation

appendAndReturnTree()

pt::ptree ParameterTable::appendAndReturnTree

(

G4String

p_fileName

)

Appends information of json-file containing PMT/OM parameters to a dictionary of ptrees

Parameters

p_fileName

Name of file containing json

checkIfKeyInTree()

G4bool ParameterTable::checkIfKeyInTree	(	G4String	p_treeName,
		G4String	p_key
	)

Parameters

p_treeName	Name of the JSON tree to search in.
p_key	Key to look for in the tree.

Returns

true if the key exists in the tree, false otherwise.

checkIfTreeNameInTable()

G4bool ParameterTable::checkIfTreeNameInTable

(

G4String

pKey

)

Parameters

pKey	The key to check.

Returns

true if the key exists, false otherwise.

getJSONTree()

pt::ptree ParameterTable::getJSONTree

(

G4String

pKey

)

Get tree object saved in table

Parameters

pKey	Key of tree ("jName" in corresponding json file)

Returns

pt::ptree

getValue()

template<typename T >

T ParameterTable::getValue ( G4String  pKey, G4String  pParameter  )

inline

Template Parameters

T	The type of the value to fetch.

Parameters

pKey	The main key.
pParameter	The parameter within the main key's tree.

Returns

The value associated with the key and parameter.

getValueWithUnit()

G4double ParameterTable::getValueWithUnit	(	G4String	pKey,
		G4String	pParameter
	)

Parameters

pKey	The main key.
pParameter	The parameter within the main key's tree.

Returns

The value associated with the key and parameter, with units converted to Geant4-compatible units.

parseKeyContentToVector() [1/2]

template<typename T >

void ParameterTable::parseKeyContentToVector ( std::vector< T > &  pVector, pt::ptree  pTree, std::basic_string< char >  pKey, G4double  pScaling, bool  pInverse  )

inline

Parameters

pVector	Vector where the values will be stored.
pTree	JSON subtree to extract values from.
pKey	JSON key whose associated array values are to be extracted.
pScaling	Scaling factor applied to each value.
pInverse	If true, the value is divided by the scaling factor, if false it's multiplied.

Template Parameters

T	Type of the values to be extracted from the JSON tree.

parseKeyContentToVector() [2/2]

template<typename T >

void ParameterTable::parseKeyContentToVector ( std::vector< T > &  pVector, std::basic_string< char >  p_MapKey, std::basic_string< char >  pKey, G4double  pScaling, bool  pInverse  )

inline

This overloaded method additionally requires a map key to first retrieve the JSON subtree.

Parameters

pVector	Vector where the values will be stored.
p_MapKey	Key of the JSON map to retrieve the desired subtree.
pKey	JSON key within the subtree whose associated array values are to be extracted.
pScaling	Scaling factor applied to each value.
pInverse	If true, the value is divided by the scaling factor, if false it's multiplied.

Template Parameters

T	Type of the values to be extracted from the JSON tree.

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

• OMSimInputData.hh
• OMSimInputData.cc