Support for partialDate and similars

[stefanverbeeck]

Hi,

I'm working on an implementation to convert SDTM datasets to CDISC JSON.

In trying to complete the "columns" property, I noticed that the documentation does not provide context on how exactly the datatypes from ODM should be mapped to those from JSON.

The relevant part from the doc simply lists the supported types.
(found at https://github.com/cdisc-org/DataExchange-DatasetJson/blob/master/doc/dataset-json1-1.md#column-metadata)

I can logically assign most normal datatypes like "text" is "string" etc.
But some datatypes from ODM like "partialDate" or "intervalDatetime" are not mentioned.

Somewhat related;
I noticed that in the example ae.json - AESTDTC is as type "date" whilst in lb.json - LBDTC is type "string" (but without length property).
Not sure what to use now for dates.

Can this be clarified how dates, partialdates and related items are to be displayed in the JSON?

Thanks in advance,

[lexjansen]

The Dataset-JSON standard contains only a limited subset of Define-XML metadata. The idea is to include enough metadata so that applications like viewers or conversion tools can do their job.
Define-XML data types like partialDate, partialTime, partialDatetime, incompleteDatetime, durationDatetime, and intervalDatetime are not supported by either source systems, target systems or JSON. These Define-XML data types would be represented as text strings in source systems, target systems or JSON. For this reason we are representing them as the JSON dataType="string".
Since easy conversions to R or SAS datasets is a key feature of Dataset-JSON, and SAS and R don't support partialDatetime, using string simplifies data exchange.
Length is not a required property in Dataset-JSON, but in the examples we kept the length for variables that were defined with DataType="text" in the associated Define-XML. It would certainly not be wrong to add a length value for a variable that has a "partialDatetime" Define-XML DataType. Just like in the Define-XML specification, the variable lengths are planned lengths.
In the example AESTDTC had Define-XML DataType="date", whereas LBDTC has "partialDatetime".