View source for Item:OSW911488771ea449a6a34051f8213d7f2f

==JSON-LD: Motivation ==
Problem: Everybody uses different keys<div style=" column-count: 3;">
<div>JSON Dataset 1
<syntaxhighlight lang="json">
{
    "c": 1.0
}
</syntaxhighlight>
</div>
<div>JSON Dataset 2
<syntaxhighlight lang="json">
{
    "cap": 1.0
}
</syntaxhighlight>
</div>
<div>
Do they mean the same?
</div>
</div>

==JSON-LD: Mapping (1)==
Idea: Map keys to common vocabularies like https://www.qudt.org/doc/DOC_VOCAB-QUANTITY-KINDS.html
<div style=" column-count: 3;">
<div>JSON Dataset 1
<syntaxhighlight lang="json-ld">
{
    "@context": {
        "c": "http://qudt.org/vocab/quantitykind/Capacitance"  
    },
    "c": 1.0
}
</syntaxhighlight>
</div>
<div>JSON Dataset 2
<syntaxhighlight lang="json-ld">
{    
    "@context": {
        "cap": "http://qudt.org/vocab/quantitykind/Capacitance"  
    },
    "cap": 1.0
}
</syntaxhighlight>
</div>
<div>
Do they mean the same? Yes!
</div>
</div>

== JSON-LD: Mapping (2) ==
JSON-LD allows the definition of prefixes
<syntaxhighlight lang="json-ld">
{
    "@context": {
        "qudt": "http://qudt.org/vocab/quantitykind/",
        "cap": "qudt:Capacitance",        
    },
    "cap": 1.0
}
</syntaxhighlight><div></div>

== JSON-LD: Mapping (3) - Remote context==
JSON-LD allows the import of context(s) from other JSON documents
* Prefixes and mappings can be moved to a remote context 
<nowiki>http://myschema.org/allmyquantitites.jsonld</nowiki><syntaxhighlight lang="json-ld">
{
    "@context": {
        "qudt": "http://qudt.org/vocab/quantitykind/",
        "cap": "qudt:Capacitance",        
    }
}
</syntaxhighlight><syntaxhighlight lang="json-ld">
{
    "@context": [
        "http://myschema.org/allmyquantitites.jsonld"
        {
            "current": "qudt:Current",        
        }
    ],
    "cap": 1.0,
    "current": 10.0 
}
</syntaxhighlight>

== JSON-LD: Mapping (4) - Full example ==
Actually this example was oversimplified. A full semantic representation would be

<nowiki>http://myschema.org/allmyquantitites.jsonld</nowiki><syntaxhighlight lang="json-ld">
{
    "@context": {
        "qudt": "http://qudt.org/schema/qudt/",
        "qunit": "http://qudt.org/vocab/unit/",
        "qkind": "http://qudt.org/vocab/quantkind/",
        "unit": {
          "@id": "qudt:hasUnit",
          "@type": "@id"
        },
        "value": "qudt:value"   
    }
}
</syntaxhighlight><syntaxhighlight lang="json-ld">
{
  "@context": "http://myschema.org/allmyquantitites.jsonld",
  "value": 4.0,
  "unit": "qunit:CentiM"
}
</syntaxhighlight>which would translate to <code><pint.Quantity(4.0, 'centimeter')></code> in python, see [https://github.com/hampusnasstrom/ontopint]<div>
== JSON-LD: Advanced concepts==
There are many more feature of JSON-LD - see specification [https://www.w3.org/TR/json-ld/]

* Property types, object properties
* Reverse Properties
* Arrays and containers
* Multi-language strings
* Framing
* ...

In general JSON-LD is not only about annotation but also transformation and normalization

== JSON-LD: Scopes ==
A property / the related subobject can have it's own context. The global context is inherited. [https://json-ld.org/playground/#startTab=tab-expanded&json-ld=%7B%22%40context%22%3A%7B%22test%22%3A%22http%3A%2F%2Ftest.org%2F%22%2C%22id%22%3A%22test%3AHasId%22%2C%22name%22%3A%22test%3AHasName%22%2C%22subobject%22%3A%7B%22%40id%22%3A%22test%3AHasSubobject%22%2C%22%40context%22%3A%7B%22id%22%3A%22test%3AHasSubId%22%7D%7D%7D%2C%22name%22%3A%22Test%201%22%2C%22id%22%3A%221%22%2C%22subobject%22%3A%7B%22name%22%3A%22Test%201.1%22%2C%22id%22%3A%221.1%22%7D%7D&context=%7B%7D Playground]
<syntaxhighlight lang="json-ld">
{
  "@context": {
    "test": "http://test.org/",
    "id": "test:HasId",
    "name": "test:HasName",
    "subobject": {
      "@id": "test:HasSubobject",
      "@context": {
        "id": "test:HasSubId"
      }
    }
  },
  "name": "Test 1",
  "id": "1",
  "subobject": {
    "name": "Test 1.1",
    "id": "1.1"
  }
}
</syntaxhighlight><div></div>
</div>

==JSON-LD: Flatten a hierarchy==
[https://json-ld.org/playground/#startTab=tab-flattened&json-ld=%7B%22%40context%22%3A%7B%22%40version%22%3A1.1%2C%22%40vocab%22%3A%22http%3A%2F%2Fexample.org%2F%22%2C%22id%22%3A%22%40id%22%7D%2C%22%40id%22%3A%22http%3A%2F%2Fexample.org%2FSM1%22%2C%22%40type%22%3A%22Model%22%2C%22contains%22%3A%7B%22%40id%22%3A%22http%3A%2F%2Fexample.org%2FSM2%22%2C%22%40type%22%3A%22Submodel%22%2C%22contains%22%3A%7B%22%40id%22%3A%22http%3A%2F%2Fexample.org%2FSM3%22%2C%22%40type%22%3A%22Submodel%22%2C%22contains%22%3A%7B%22%40id%22%3A%22http%3A%2F%2Fexample.org%2FSM4%22%2C%22%40type%22%3A%22Submodel%22%2C%22hasParameter%22%3A%7B%22%40id%22%3A%22http%3A%2F%2Fexample.org%2FP2%22%2C%22%40type%22%3A%22Parameter%22%2C%22title%22%3A%22P2%22%2C%22value%22%3A2%7D%2C%22title%22%3A%22Submodel%204%22%7D%2C%22hasParameter%22%3A%7B%22%40id%22%3A%22http%3A%2F%2Fexample.org%2FP3%22%2C%22%40type%22%3A%22Parameter%22%2C%22title%22%3A%22P3%22%2C%22value%22%3A3%7D%2C%22title%22%3A%22Submodel%203%22%7D%2C%22hasParameter%22%3Anull%2C%22title%22%3A%22Submodel%202%22%7D%2C%22hasParameter%22%3A%7B%22%40id%22%3A%22http%3A%2F%2Fexample.org%2FP1%22%2C%22%40type%22%3A%22Parameter%22%2C%22title%22%3A%22P1%22%2C%22value%22%3A1%7D%7D&frame=%7B%7D&context=%7B%7D Playground]<div style=" column-count: 3;">
<div style="break-inside: avoid;">Input
<syntaxhighlight lang="json-ld">
{
  "@context": {
    "@version": 1.1,
    "@vocab": "http://example.org/"
  },
  "@id": "http://example.org/SM1",
  "@type": "Model",
  "contains": {
    "@id": "http://example.org/SM2",
    "@type": "Submodel",
    "contains": {
      "@id": "http://example.org/SM3",
      "@type": "Submodel",
      "contains": {
        "@id": "http://example.org/SM4",
        "@type": "Submodel",
        "hasParameter": {
          "@id": "http://example.org/P2",
          "@type": "Parameter",
          "title": "P2",
          "value": 2
        },
        "title": "Submodel 4"
      },
      "hasParameter": {
        "@id": "http://example.org/P3",
        "@type": "Parameter",
        "title": "P3",
        "value": 3
      },
      "title": "Submodel 3"
    },
    "hasParameter": null,
    "title": "Submodel 2"
  },
  "hasParameter": {
    "@id": "http://example.org/P1",
    "@type": "Parameter",
    "title": "P1",
    "value": 1
  }
}
</syntaxhighlight>
</div>
<div style="break-inside: avoid;">
=>
</div>
<div style="break-inside: avoid;">Flattened output
<syntaxhighlight lang="json-ld">
{
  "@graph": [
    {
      "@id": "http://example.org/P1",
      "@type": "http://example.org/Parameter",
      "http://example.org/title": "P1",
      "http://example.org/value": 1
    },
    {
      "@id": "http://example.org/P2",
      "@type": "http://example.org/Parameter",
      "http://example.org/title": "P2",
      "http://example.org/value": 2
    },
    {
      "@id": "http://example.org/P3",
      "@type": "http://example.org/Parameter",
      "http://example.org/title": "P3",
      "http://example.org/value": 3
    },
    {
      "@id": "http://example.org/SM1",
      "@type": "http://example.org/Model",
      "http://example.org/contains": {
        "@id": "http://example.org/SM2"
      },
      "http://example.org/hasParameter": {
        "@id": "http://example.org/P1"
      }
    },
    {
      "@id": "http://example.org/SM2",
      "@type": "http://example.org/Submodel",
      "http://example.org/contains": {
        "@id": "http://example.org/SM3"
      },
      "http://example.org/title": "Submodel 2"
    },
    {
      "@id": "http://example.org/SM3",
      "@type": "http://example.org/Submodel",
      "http://example.org/contains": {
        "@id": "http://example.org/SM4"
      },
      "http://example.org/hasParameter": {
        "@id": "http://example.org/P3"
      },
      "http://example.org/title": "Submodel 3"
    },
    {
      "@id": "http://example.org/SM4",
      "@type": "http://example.org/Submodel",
      "http://example.org/hasParameter": {
        "@id": "http://example.org/P2"
      },
      "http://example.org/title": "Submodel 4"
    }
  ]
}
</syntaxhighlight>
</div>
</div>

==JSON-LD: Rebuild a hierarchy==
[https://json-ld.org/playground/#startTab=tab-framed&json-ld=%7B%22%40context%22%3A%7B%22%40vocab%22%3A%22http%3A%2F%2Fexample.org%2F%22%2C%22ex%22%3A%22http%3A%2F%2Fexample.org%2F%22%2C%22contains%22%3A%7B%22%40type%22%3A%22%40id%22%7D%2C%22hasParameter%22%3A%7B%22%40type%22%3A%22%40id%22%7D%2C%22parameterOf%22%3A%7B%22%40type%22%3A%22%40id%22%2C%22%40reverse%22%3A%22hasParameter%22%7D%2C%22submodels%22%3A%22%40graph%22%7D%2C%22%40id%22%3A%22ex%3ASM1%22%2C%22%40type%22%3A%22Model%22%2C%22contains%22%3A%22ex%3ASM2%22%2C%22hasParameter%22%3A%22ex%3AP1%22%2C%22submodels%22%3A%5B%7B%22%40id%22%3A%22ex%3ASM2%22%2C%22%40type%22%3A%22Submodel%22%2C%22title%22%3A%22Submodel%202%22%2C%22contains%22%3A%22ex%3ASM3%22%7D%2C%7B%22%40id%22%3A%22ex%3ASM3%22%2C%22%40type%22%3A%22Submodel%22%2C%22title%22%3A%22Submodel%203%22%2C%22contains%22%3A%22ex%3ASM4%22%7D%2C%7B%22%40id%22%3A%22ex%3ASM4%22%2C%22%40type%22%3A%22Submodel%22%2C%22title%22%3A%22Submodel%204%22%2C%22hasParameter%22%3A%22ex%3AP2%22%7D%2C%7B%22%40type%22%3A%22Parameter%22%2C%22%40id%22%3A%22ex%3AP1%22%2C%22title%22%3A%22P1%22%2C%22value%22%3A1%7D%2C%7B%22%40type%22%3A%22Parameter%22%2C%22%40id%22%3A%22ex%3AP2%22%2C%22title%22%3A%22P2%22%2C%22value%22%3A2%7D%2C%7B%22%40type%22%3A%22Parameter%22%2C%22%40id%22%3A%22ex%3AP3%22%2C%22title%22%3A%22P3%22%2C%22value%22%3A3%2C%22parameterOf%22%3A%22ex%3ASM3%22%7D%5D%7D&frame=%7B%22%40context%22%3A%7B%22%40version%22%3A1.1%2C%22%40vocab%22%3A%22http%3A%2F%2Fexample.org%2F%22%7D%2C%22%40type%22%3A%22Model%22%2C%22contains%22%3A%7B%22%40type%22%3A%22Submodel%22%2C%22contains%22%3A%7B%22%40type%22%3A%22Submodel%22%7D%2C%22hasParameter%22%3A%7B%22%40type%22%3A%22Parameter%22%7D%7D%2C%22hasParameter%22%3A%7B%22%40type%22%3A%22Parameter%22%7D%7D Playground]<div style=" column-count: 3;">
<div style="break-inside: avoid;">Input
<syntaxhighlight lang="json-ld">
{
  "@context": {
    "@vocab": "http://example.org/",
    "ex": "http://example.org/",
    "contains": {
      "@type": "@id"
    },
    "hasParameter": {"@type": "@id"},
    "parameterOf": {"@type": "@id", "@reverse": "hasParameter"},
    "submodels": "@graph"
  },
    "@id": "ex:SM1",
    "@type": "Model",
    "contains": "ex:SM2",
  	"hasParameter": "ex:P1",
  	"submodels": [
    {
      "@id": "ex:SM2",
      "@type": "Submodel",
      "title": "Submodel 2",
      "contains": "ex:SM3"
    },
    {
      "@id": "ex:SM3",
      "@type": "Submodel",
      "title": "Submodel 3",
      "contains": "ex:SM4"
    },
    {
      "@id": "ex:SM4",
      "@type": "Submodel",
      "title": "Submodel 4",
      "hasParameter": "ex:P2"
    },
    {
      "@type": "Parameter",
      "@id": "ex:P1",
      "title": "P1",
      "value": 1.0
    },
    {
      "@type": "Parameter",
      "@id": "ex:P2",
      "title": "P2",
      "value": 2.0
    },
    {
      "@type": "Parameter",
      "@id": "ex:P3",
      "title": "P3",
      "value": 3.0,
      "parameterOf": "ex:SM3"
    }
  ]
}
</syntaxhighlight>
</div>
<div style="break-inside: avoid;">Frame
<syntaxhighlight lang="json-ld">
{
  "@context": {
    "@version": 1.1,
    "@vocab": "http://example.org/"
  },
  "@type": "Model",
  "contains": {
    "@type": "Submodel",
    "contains": {
      "@type": "Submodel"
    },
      "hasParameter": {
    "@type": "Parameter"
  }
  },
  "hasParameter": {
    "@type": "Parameter"
  }
}
</syntaxhighlight>
</div>
<div style="break-inside: avoid;">Framed output
<syntaxhighlight lang="json-ld">
{
  "@context": {
    "@version": 1.1,
    "@vocab": "http://example.org/"
  },
  "@id": "http://example.org/SM1",
  "@type": "Model",
  "contains": {
    "@id": "http://example.org/SM2",
    "@type": "Submodel",
    "contains": {
      "@id": "http://example.org/SM3",
      "@type": "Submodel",
      "contains": {
        "@id": "http://example.org/SM4",
        "@type": "Submodel",
        "hasParameter": {
          "@id": "http://example.org/P2",
          "@type": "Parameter",
          "title": "P2",
          "value": 2
        },
        "title": "Submodel 4"
      },
      "hasParameter": {
        "@id": "http://example.org/P3",
        "@type": "Parameter",
        "title": "P3",
        "value": 3
      },
      "title": "Submodel 3"
    },
    "hasParameter": null,
    "title": "Submodel 2"
  },
  "hasParameter": {
    "@id": "http://example.org/P1",
    "@type": "Parameter",
    "title": "P1",
    "value": 1
  }
}
</syntaxhighlight>
</div>
</div>

==JSON Documents: Next==
*[[Item:OSWee501c0fa6a9407d99c058b5ff9d55b4]] [{{fullurl:Item:OSWee501c0fa6a9407d99c058b5ff9d55b4
|reveal=true
}} Slideshow]