QUnitConversion

Overview

QUnitConversion is a simple lightweight library providing tools for runtime unit conversion built on top of Qt5 Framework.

QUnitConversion stores units as strings grouped by "family" (for example length or temperature). Each family has its own base unit, conversion inside a family is performed by converting through base unit providing conversion from any unit to any other unit in a family. Conversion rules can be added dynamically and/or loaded from JSON-formatted string so you can add your own conversions if needed. An example of an input JSON file is provided in test/testdata/conversion_rules.json.

Note that each unit should have a unique name, as long as conversion is unit name-based.

QUnitConversion supports aliases for unit names, see aliases example below.

Documentation

Documentation is available here

Examples

Basic usage:

QUnitConvertor convertor;

// fill the convertor instance with rules
convertor.addConversionRule(QUnitConversionRule("length", "m", "km", 0.001, 0));
convertor.addConversionRule(QUnitConversionRule("length", "m", "cm", 100, 0));

// you can convert a single value
double km = convertor.convert(50, "km", "m");   // returns value of a 50 km converted to meters

// or get a linear function that holds conversion from one unit to another
// to apply this convertion to many numbers without finding a conversion each time 
QLinearFunction convertFunction = convertor.convert("m", "km");
std::vector<double> meters;
// meters is filled here...
std::vector<double> kilometers;
for (double m: meters)
    kilometers.push_back(convertFunction.y(m));

Aliases:

QUnitConversion supports aliases for units with possible conversion on the fly, so you km/h, kmph and kmh will be converted to m/s properly. Also this example illustrates loading conversions and aliases from JSON-formatted file.

QUnitConvertor convertor;

// load conversion rules from JSON
QFile conversions("conversion_rules.json");
conversions.open(QIODevice::ReadOnly);
convertor.loadFromJson(QJsonDocument::fromJson(conversions.readAll()).object());

// load aliases for unit names from JSON
QFile aliases("aliases.json");
aliases.open(QIODevice::ReadOnly);
convertor.loadAliasesFromJson(QJsonDocument::fromJson(aliases.readAll()).object());

double km;
km = convertor.convert(50, "km", "m");   // returns value of a 50 km converted to meters
km = convertor.convert(50, "km", "meter");  // "meter" is an alias for "m" written in loaded json
km = convertor.convert(50, "km", "meters"); // and "meters" a as well

License

QUnitConversion is distributed under MIT license

Repo contents

Directory	Contents
./QUnitConversion	Library source code.
./tests	Unittests code.

Copyright Dmitriy Linev 2020-2022