I am doing the same thing and want to convert a SPIN Map mapping that I am using with XML and have been asked to use JSON instead.
TBCME has a ConvertXMLToRDF SPARQL Motion module that takes plain (but valid) XML and produces a default RDF graph. I then use a SPIN Map to map from that generic RDF to my target schema. This works great. I expected the ConvertJSONToRDF module to work the same way; that TBCME would read the JSON, convert it to a generic RDF that would look the same as the previous one (since I converted the XML to JSON to test everything). All I expected to have to do was to swap the ConvertXMLToRDF module with the ConvertJSONToRDF module. If I stop the execution after this module there are a number of instances of the http://topbraid.org/json namespace (which doesn't appear to exist) but the next conversion doesn't work. I do not want to use GraphQL or SHACL or SWP to do this, just SPARQL Motion, SPIN Map, and the published modules. Please advise. Jack On Tuesday, August 20, 2019 at 1:23:43 PM UTC-7 Irene Polikoff wrote: > Hi Daniel, > > The key piece is to have SHACL Shapes that correspond to the structure of > your JSON. They are used to guide the conversion. > > If you already have a GraphQL schema for your JSON, TopBraid EDG can > create SHACL Shapes from it. > > For example, in TBC, you could use Import: > > > Technical details behind how this works are here: > https://www.topquadrant.com/graphql/graphql-shacl.html > > > sml:ConvertJSONToRDF described below by Holger, has the following > arguments: > > > - sml:keepRootObject (xsd:boolean): [Optional] In GraphQL mode > (sml:service is provided) then the root object is typically just a > container derived from the Query. By default, the triples of this root > object will not be kept. Set to true to keep these triples in the result > graph. > - sm:outputVariable (xsd:string): [Optional] The name of the result > variable (defaults to "root") that will contain the root object of the > converted JSON code. > - sml:service (graphql:Schema): [Optional] A GraphQL service object > providing information on how to map the JSON to RDF using SHACL shapes. > - sml:text (xsd:string): The JSON input text, either a JSON object or > array. > > > If you do not have a GraphQL Schema for your JSON, then you could start by > creating a SHACL model that correspond to your JSON. Internally, TopBraid > will automatically generate a GraphQL Schema from SHACL that will be used > to guide the import and transformation of JSON. > > Technical details of how GraphQL Schemas are generated from SHACL are here > https://www.topquadrant.com/graphql/shacl-graphql.html. Yes, this is used > to query RDF with GraphQL and get JSON out. But it is also used in the > other direction, to convert JSON to RDF. > > Also see answers below > > On Aug 20, 2019, at 1:46 PM, Daniel Lavoie <daniel.j...@gmail.com> wrote: > > And: > > - Can we use TBC Maestro for the development? > > Yes. You can develop the import process using the suggested module/API. > You can test the script in TBC. However, TBC is a single user, not > networked tool. For doing the scheduled processing (assuming this is not a > one-of and your JSON comes in on a regular basis), you will need a server. > > > - Can we implement the result in a triple store? > > Yes, sure > > > - Does it have to be EDG triple store or can we use another one like > Stardog? > > > The transformation will create RDF from JSON, you can decide what to do > with it e.g., write it into EDG’s triple store, export it as file into one > of the serialized formats, etc. > > Thanks again! > Daniel > > On Tuesday, August 20, 2019 at 10:49:15 AM UTC-4, Daniel Lavoie wrote: >> >> Thank you very much Holger for your answer. I have listened to the >> webminar you have suggested, but most of it is about producing JSON from >> RDF. However, I want to do the opposite. I am very interested of learning >> more about the JSON to RDF conversion using SHACL. In fact, I would want >> to: >> >> - Generate the IRIs as we want (its seems that is possible using >> GRAPH QL templates) >> - Map the JSON field names to Property IRIs. >> - Validate the JSON fields and values. >> >> Where can I find more information about the JSON to RDF conversion using >> GraphQL and SHACL? >> >> Regards >> Daniel >> On Monday, August 19, 2019 at 8:15:16 PM UTC-4, Holger Knublauch wrote: >>> >>> Hi Daniel, >>> >>> there is a variety of options here. >>> >>> Obviously, if the file is JSON-LD then it can be opened like any other >>> RDF graph, assuming it ends with .jsonld. JSON-LD has been designed with a >>> notion of Contexts that provide some flexibility as an on-the-fly transform >>> from many JSON tree structures into JSON-based graph structure. >>> >>> If the file is not JSON-LD and you cannot define a suitable JSON-LD >>> context then you could use our generic JSON importer that can transform any >>> JSON into either a "default" RDF graph or into a graph that is described >>> using SHACL shapes. The SPARQLMotion module to invoke that feature is >>> sml:ConvertJSONToRDF. Here is the documentation comment of that: >>> >>> --- >>> Takes a JSON object or array (represented as text) and converts it to >>> RDF triples with the same structure. The result graph will only contain the >>> generated triples - the input graph will be ignored and may need to be >>> passed on with a separate sm:next relationship. The graph uses the >>> namespace prefix. >>> >>> This module operates in two modes. By default it will use the "json" >>> namespace (http://topbraid.org/json#) for properties and create blank >>> nodes of type json:Object. However, if sml:service is set it will look for >>> GraphQL shapes and walk them in parallel to the JSON object tree. >>> >>> The conversion will start at the JSON root and does a recursive walk >>> through of the JSON objects and arrays. Each JSON object becomes a >>> resource. Each attribute of the JSON object is mapped into a property. In >>> the simple case, it will pick a property from the json namespace, e.g. >>> attribute "firstName" becomes a property json:firstName. In simple mode, >>> the values of those properties depend on the JSON attribute value and >>> arrays are converted to rdf:Lists, JSON objects recursively become new >>> blank nodes. Numbers, booleans and strings become corresponding RDF >>> literals. In GraphQL mode, the shapes define how the mapping is performed >>> and the root node must be a JSON object. >>> >>> Optionally, the module can bind a new variable pointing at the root >>> object of the new JSON data structure in RDF. This does not work if the >>> provided JSON string is an Array with multiple entries. >>> --- >>> With the SHACL-based approach, you start by declaring the shape of the >>> target data, e.g. if the RDF data should use xsd:double for a property >>> ex:value and your JSON only contains { value: 4.2 } then the shape would >>> define a sh:property constraint of sh:datatype xsd:double on sh:path >>> ex:value. A side benefit of this design is that you can validate the >>> conformance of your JSON with the shapes. This topic is briefly mentioned >>> in this presentation (around minute 47), but you may want to watch most of >>> the presentation to understand the general design philosophy of the mapping >>> from JSON/GraphQL to RDF/SHACL: >>> >>> https://www.youtube.com/watch?v=Muj0m8Qrdig >>> >>> The SHACL-less alternative would be to use the default "json" namespace >>> and then use modules such as sml:ApplyConstruct to produce the target >>> triples in their respective namespaces. >>> Note that sml:ConvertJSONToRDF can also be called from within SWP >>> scripts, which is sometimes less busy than SPARQLMotion. >>> >>> Speaking about SWP, there is a number of built-in features to process >>> arbitrary JSON on a more "native" level, and then produce whatever you want >>> with it, see https://uispin.org/ui.html#json >>> >>> A completely different alternative is to use a 3rd party component or >>> program to produce the RDF/Turtle. >>> >>> HTH >>> Holger >>> >>> >>> On 20/08/2019 03:40, Daniel Lavoie wrote: >>> >>> Hi, >>> >>> Does TopQuadrant has any tool allowing us to read JSON files and to map >>> them to produce RDF turtle files? Can SPARQLMotion do that? >>> >>> Thanks >>> Daniel >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "TopBraid Suite Users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to topbrai...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/topbraid-users/d98fbd11-a8b3-49a4-bb8c-4350676bc0f3%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/topbraid-users/d98fbd11-a8b3-49a4-bb8c-4350676bc0f3%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >>> > -- > You received this message because you are subscribed to the Google Groups > "TopBraid Suite Users" group. > > To unsubscribe from this group and stop receiving emails from it, send an > email to topbraid-user...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/topbraid-users/e9dd8639-8b2a-420c-a106-4f54e7d39808%40googlegroups.com > > <https://groups.google.com/d/msgid/topbraid-users/e9dd8639-8b2a-420c-a106-4f54e7d39808%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > -- You received this message because you are subscribed to the Google Groups "TopBraid Suite Users" group. 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