Dealing with lists in a json-formatted data

[huanyu-li]

Hi,

May I just ask a question about if RML supports to deal multiple lists from a JSON-formatted data in one triples map? For instance, my json response looks like: { "data":{ "id": "MY_ID", "A": [A0, A1, A2], "B": [B0, B1, B2] } } In my RDF graph, I want to have such triples: 'http://example.com/MY_ID/0' 'has_A' 'A0' 'http://example.com/MY_ID/0' 'has_B' 'B0' 'http://example.com/MY_ID/1' 'has_A' 'A1' 'http://example.com/MY_ID/1' 'has_B' 'B1' 'http://example.com/MY_ID/2' 'has_A' 'A2' 'http://example.com/MY_ID/2' 'has_B' 'B2'

And the lengths of lists for "A" may be different in different json responses, but they are always same as those for "B".

Thank you in advance. Best, Huanyu

[DylanVanAssche]

Hi @huanyu-li !

RML can deal with the lists but not like this I'm afraid. The IRIs are constructed through the array index which is not available with JSONPath. You need at least a JSONPath expression to iterate over the data.

[huanyu-li]

Thank you so much for the reply, @DylanVanAssche. It makes sense to me now.

[huanyu-li]

Hi @DylanVanAssche,

May I ask if this feature like getting index of a list is interested for KG construction? Or could you point to me if I can modify RML code somewhere to implement this feature by my self.

[DylanVanAssche]

Hi!

Index based access of lists are definitely useful, the problem here is access via JSONPath. That's the access description for JSON files here. If you can find a syntax for index based access in JSONPath, it could be integrated.

[bjdmeest]

(Just letting you know I'm putting this on the W3C community group radar, see referenced issue above)