How to assign a unique identification to a JSON type in JSON Schema?

Using "definitions" and "$ref" properties allows to define JSON types and reference them internally in the same JSON schema or externally in another JSON schema.

You can also assign a unique identification to a JSON type with the "$id" property and reference them internally in the same JSON schema or externally in another JSON schema.

The "$id" property uses the URI syntax to assign unique identifications to JSON types in 3 different formats:

1. Absolute full URI - The JSON type is identified globally by the given URI. For example, the following JSON schema defines 2 JSON types named as "rating" and "yesNo" and assigns 2 full URIs as their "$id":

{
    "definitions": {
        "rating": {
		    "$id": "http://dev.fyicenter.com/JSON/schema.json#point",
            "type": "integer",
        },
		"yesNo": {
		    "$id": "urn:uuid:ee564b8a-7a87-4125-8c96-e9f123d6766f",
             "enum": ["yes", "no"]
		}
    },
	...
}

2. Relative URI path - The JSON type is identified globally by the combination of the base URI of the parent type identification and the given URI path. For example, the following JSON schema defines a JSON type called "rating" and assign a URI path to it:

{   
    "$id": "http://dev.fyicenter.com/JSON/schema.json",
    "definitions": {
        "rating": {
		    "$id": "/JSON/survey.json#point",
            "type": "integer",
        }
    },
	...
}

The "rating" JSON type's global identification will be constructed by taking the URI base from the parent "$id" and concatenate with the given URI path: "http://dev.fyicenter.com/JSON/survey.json#point"

3. Internal bookmark - The JSON type is identified globally by the combination of the URI of the parent type identification and the given bookmark. For example, the following JSON schema defines a JSON type called "rating" and assign a bookmark to it:

{   
    "$id": "http://dev.fyicenter.com/JSON/schema.json",
    "definitions": {
        "rating": {
		    "$id": "#point",
            "type": "integer",
        }
    },
	...
}

The "rating" JSON type's global identification will be constructed by taking the URI from the parent "$id" and concatenate with the given bookmark: "http://dev.fyicenter.com/JSON/schema.json#point"

 

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