DCTAP features support

[labra]

In this issue we will collect what features from DCTAP we support in rudof.

Link to DCTAP spec.

DCTAP elements

• shapeID
• shapeLabel
• propertyID
• propertyLabel
• mandatory
• repeatable
• valueNodeType
• valueDataType
• valueShape
• valueConstraint
• valueConstraintType
• note

Extensions proposed in DCTap cookbook:

Value constraint types

• iriStem
• min
• minValue
• maxValue
• range
• minLength
• maxLength
• minOccur
• maxOccur
• occur

Defining order of properties. See this section

• orderNo

Multiple values in a cell. See this section

• pickList

Several properties in the same line. See this section

• Allow to define several properties in a single row

An "Or" of valueNodeTypes. See this section

• Support for ORs in value node types

Either/OR valueNodeType. See this section

• Support repeated properties which can be an OR

Namespace declarations

• At this moment namespace declarations are injected through the config file.

Other DCTAP elements:

• extends: it is supported
• extendsLabel: This is supported but it is redundant because the label should be defined in the extended shape, so we may remove its support.

[kcoyle]

In theory, any of the cells in a DCTAP can have multiple values. The valueConstraintType is probably the only one where this is illogical. It is also unlikely in the shapeID (I haven't thought through what it would mean in a shapeID.) These are usually single strings separate by a space: "IRI BNODE" or "https://id.loc.gov https://viaf.org". If you have a multi-word value, then you need to use commas: "bedroom, living room, kitchen". The SRAP DCTAP has examples where the valueShape has multiple values. Multiple values are assumed to be in an 'OR' relationship.

Also, recall that DCTAPs can have blank lines. They aren't meaningful, they are just for readability.