volcart::Metadata Class Reference

Generic interface for storing metadata as key/value pairs. More...

#include <vc/core/types/Metadata.hpp>

Public Member Functions
	Metadata ()=default
	Default constructor.
	Metadata (const filesystem::path &fileLocation)
	Read a metadata file from disk. More...
auto	path () const -> filesystem::path
	Get the path where the metadata file will be written.
void	setPath (const filesystem::path &path)
	Set the path where the metadata file will be written.
void	save () const
	Save the metadata file to the stored path. More...
void	save (const filesystem::path &path) const
	Save the metadata file to a specified path.
auto	hasKey (const std::string &key) const -> bool
	Return whether the given key is defined.
template<typename T >
auto	get (const std::string &key) const -> std::optional< T >
	Get a metadata value by key. More...
template<typename T >
void	set (const std::string &key, T value)
	Set a metadata key and value. More...
void	printObject () const
	Print an object representation of the metadata to std::cout. More...

Protected Attributes
nlohmann::json	json_ {}
filesystem::path	path_

Detailed Description

Generic interface for storing metadata as key/value pairs.

Author

Sean Karlage, Seth Parker

Date

10/27/15

Internally uses JSON for Modern C++ for easy storage and [de]serialization: https://nlohmann.github.io/json/

Definition at line 26 of file Metadata.hpp.

Constructor & Destructor Documentation

Metadata()

volcart::Metadata::Metadata ( const filesystem::path &  fileLocation )

explicit

Read a metadata file from disk.

Exceptions

volcart::IOException

Member Function Documentation

get()

template<typename T >

auto volcart::Metadata::get ( const std::string &  key ) const -> std::optional<T>

inline

Get a metadata value by key.

If the stored value is convertible to T, the returned optional will have an assigned value. If the stored value is null, the returned optional will have no value. This can be checked with result.has_value(), and the value can be retrieved with result.value().

Exceptions

std::runtime_error

If the key is not present.

Template Parameters

T	Value return type. JSON library will attempt to convert to the specified type.

Definition at line 79 of file Metadata.hpp.

printObject()

void volcart::Metadata::printObject

(

)

const

Print an object representation of the metadata to std::cout.

Warning

This should only be used for debugging.

save()

void volcart::Metadata::save

(

)

const

Save the metadata file to the stored path.

Exceptions

IOException

set()

template<typename T >

void volcart::Metadata::set ( const std::string &  key, T  value  )

inline

Set a metadata key and value.

Template Parameters

T	Value type. JSON library will store using the specified type.

Definition at line 99 of file Metadata.hpp.

Member Data Documentation

json_

nlohmann::json volcart::Metadata::json_ {}

protected

JSON data storage

Definition at line 114 of file Metadata.hpp.

path_

filesystem::path volcart::Metadata::path_

protected

Location where the JSON file will be stored

Definition at line 116 of file Metadata.hpp.

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

• vc/core/types/Metadata.hpp