Is it possible to handle custom units in json serialization?

[giantmustache]

Is your feature request related to a problem? Please describe.
I am trying to work out a new unit. Since it is rather custom for our domain, we thought it would be best to work this out via the wiki page: https://github.com/angularsen/UnitsNet/wiki/Extending-with-Custom-Units.

It seems that the json converters cannot handle this new quantity type, since there is a direct check on the assembly to see if it can find the correct unit:

UnitsNet/UnitsNet.Serialization.JsonNet/UnitsNetBaseJsonConverter.cs

Lines 106 to 115 in 207363d

	var unitEnumTypeAssemblyQualifiedName = "UnitsNet.Units." + unitEnumTypeName + ",UnitsNet";
	// -- see http://stackoverflow.com/a/6465096/1256096 for details
	var unitEnumType = Type.GetType(unitEnumTypeAssemblyQualifiedName);
	if (unitEnumType == null)
	{
	var ex = new UnitsNetException("Unable to find enum type.");
	ex.Data["type"] = unitEnumTypeAssemblyQualifiedName;
	throw ex;
	}

Describe the solution you'd like
It would be nice if there would be a fallback mechanism that can also handle custom types. Just like the conversion functions and abbreviations, some kind of mapping mechanism could help to find more types than just the ones in the UnitsNet assembly.

Describe alternatives you've considered
As an alternative, I can write my own custom JsonConverter and use a decorator pattern to wrap the UnitsNetIQuantityJsonConverter into my own JsonConverter and ensure that GetUnit comes with correct values. These functions are not virtual in UnitsNetBaseJsonConverter, so I will need to make my own implementation and cannot make use of the base class functions.

Additional context
It would be much appreciated if the custom units could also be used inside the json serialization context, since this is essential in our software package. I think it will be a good addition to the extensibility of this package.

Greetings,
Marnix

[angularsen]

Hi and thanks for describing the issue clearly.
I agree this would be a useful feature. Would you be interested in attempting a pull request?

[giantmustache]

I made a PR with a first attempt. I understand that there are not enough unit tests and that not everything is covered. But I am wondering if this would be something within your vision of UnitsNet.

I was able to serialize and deserialize custom units now. I use the Activator class to instantiate the objects, instead of using Quantity.From(), because that generated class is lacking my custom type. I am wondering if we should get rid of Quantity.From() completely.

[lipchev]

The enums can be problematic when dealing with extended quantities and while it seems to me like there is gradual pivot towards using the Quantity/UnitInfo's instead (which you can custom-register), I don't think they would be going away completely..

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.