Transform6: outputs: profile data

[kcoyle]

• Output format(s)?
  • JSON
  • YAML
  • ??
• Output structure(s)?

  • structured, with shape and statements. Tom's example
    ShapeA
statement1
statement2
ShapeB
statement3
etc.

  • unstructured, same as rows (as output from csv-to-json), i.e.

ShapeA
statement1

ShapeA
statement2

• TAPs with no shapes
  • output just the statements?
  • use an empty shape structure? (as per Tom's example)

[tombaker]

In yesterday's call, Nishad and I argued strongly for having just one expected form of output from a DCTAP Instance: Shapes with statement constraints. The minimal DCTAP instance is a list of property identifiers, but in that case the output should show those statement constraints to be grouped in a default shape, because a shape is always expected to be present.

We had some discussion about what identifier to use for the default shape. I do not think it really matters much what identifier is used. In the 'dctap-python' utility, the default is set to be :default, but this should be configurable by the user. My readthedocs documentation puts it this way: "A default shape identifier is assigned if not provided in the CSV... In a 'shape-less' application, the shape identifier can simply be ignored."

Assigning an empty string as the default shape identifier does not seem like a good idea as it would break DCTAP instances in which a shape identifier were declared only after a series of "shape-less" statement constraints.

[kcoyle]

My only comment is that a program would need to be able to distinguish between >1 default shapeID in the same table. So whether it is "default/default1...n" or what isn't of consequence, but that possibility needs to be there.

[tombaker]

As I see it, the only thing that would trigger the creation of a default shape identifier would be the absence of any explicitly provided shape identifier. One can neglect to provide a shape identifier only once. Shape labels, for example, might be provided more than once and suggest that the author intended to declare two shapes but should not be considered grounds for assigning a second default shape identifier.

[tombaker]

The script now outputs JSON and YAML, eg:

dctap inspect --json some.csv

If there is any question about anonymous shapes, perhaps we could open a separate issue (and close this one).

[kcoyle]

The decision was to use structured output, with json and yaml being the first models offered. In TAPs with only statements (no shape)the statements will be subordinate to a default shape. If we go beyond this we can open a new issue that is more specific. I will open an issue for future consideration of validating labels without IDs. This would be just a warning. If people want to have a profile with only labels, and that works for them, so be it.