CODEWITHSUNDEEP
json-ld
user855443
user855443

Reputation: 2940

Constructing IRI from prefix and data in JSON-LD

I have a problem to construct IRI for the object using a prefix and a data value when converting non-edited JSON data into JSON-LD. The example code I have running is: 

{ 
    "@context" : 
    { "prefix" : "http://www.gerastree.at/",
      "rdfs" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
      "@vocab" : "http://example.com/" ,
      "load" : "prefix:load"
       "items" : "prefix:item"

    }, 
    "@type" : "tree",
    "@id" : "prefix:t1" , 
    "items" : 
    [
        { "@id" : "prefix:t2",
          "@type" : "item",
          "load" : "some111"
         },
        { "@id" : "prefix:t3",
          "@type" : "item",
          "load" : "some2222"
         }    
    ]
}

but when I change the @id values from "prefix:t1" to the plain data values I have in the original JSON (i.e. to just "t1", "t2" and "t3") the objects are not dealt with anymore. The code which is not proper JSON-LD (at least not read by riot)

{ 
    "@context" : 
    { "prefix" : "http://www.gerastree.at/",
      "rdfs" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
       "@vocab" : "http://example.com/" ,
       "load" : "prefix:load"
       "items" : "prefix:item"

    }, 
    "@type" : "tree",
    "@id" : "t1" , 
    "items" : 
    [
        { "@id" : "t2",
          "@type" : "item",
          "load" : "some111"
         },
        { "@id" : "t3",
          "@type" : "item",
          "load" : "some2222"
         }    
    ]
}

The value "t1" etc. are unique and I would like to use them with a prefix as IRI to link the data with other data. Is there a way to produce the IRI with some addition to the context without changing the program which produces the JSON data or edit the file.

I found a solution (based on the solution of Json-LD > Define a "person" for easy reuse as values on different keys for WebPage schema) but do not understand why it works. 

{ 
    "@context" : 
    { "prefix" : "http://www.gerastree.at/",
      "rdfs" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
       "@base" : "http://example.com/" ,
      "load" : "prefix:load",
     "items" : "prefix:item"

    }, 
    "@type" : "tree",
    "@id" : "t1" , 
    "items" : 
    [
        { "@id" : "t2",
          "@type" : "item",
          "load" : "some111"
         },
        { "@id" : "t3",
          "@type" : "item",
          "load" : "some2222"
         }    
    ]
}

I do not think this is a duplicate of Any way to specify the default URI for the @id of a @type or the values of a property? .

What additions and changes to the context are necesary?

Upvotes: 3

Views: 664

Answers (1)

user855443
user855443

Reputation: 2940

I found the explanation why my third version works as desired with some more reading of the JSON-LD recommendations and experimentation.

@vocab is applied to properties and objects only @base is used to complete IRI for the subject.

not really obvious but flexible enough for my application.

Upvotes: 1

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