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I have a JSON Schema in which I wish to define all the objects of my projects. I want to be able to validate all my objects through this single JSON Schema (using the "jsonschema" python library). I don't want to create a schema file for each object in order to avoid repetitions.

Consider the following illustrative toy example (toy-schema.json):

{
"$schema":"https://json-schema.org/draft/2020-12/schema", 
"$id":"https://example.com/toy-example.json",
"title": "JSON Schema",
"description": "JSON Schema deifning objects a,b and c",
"type": "object",
"$defs":{
    "a": {
        "$id": "#a",
        "type": "object",
        "properties": {
            "c_array": {
                "type": "array",
                "items": {
                    "$ref": "#/$defs/c"
                }
            }
        },
        "required": ["c_array"]
    },
    "b": {
        "$id": "#b",
        "type": "object",
        "properties": {
            "c": {"ref": "#/$defs/c"}
            },
        "required": ["c"]
    },
    "c": {
        "$id": "#c",
        "type": "number",
        "minimum": 0
    }
},
"allOf": [{"$ref": "#/$defs/a"}]
}

The following code works to validate an "a" object (thanks to the "allOf" instruction added at the bottom): 

import jsonschema, json
with open("toy-schema.json", "r") as f: schema = json.load(f)

a = {"c_array": [1,2,3]}
jsonschema.validate(a, schema) ## is valid, correctly stays silent
a = {"c_array": [-1,2,3]}
jsonschema.validate(a, schema) ## is invalid (-1 < 0), correctly raises ValidationError

I want to also be able to validate object "b", ideally with a syntax looking like this: 

import jsonschema, json
with open("toy-schema.json", "r") as f: schema = json.load(f)

b = {"c": 1}
jsonschema.validate(b, schema, "/$defs/#b") ## valid
b = {"c": -1}
jsonschema.validate(b, schema, "/$defs/#b") ## invalid
  • Is it possible to do this ? I.e, point to a specific portion of the schema for validation (and thus retaining references to other objects' definitions within the same schema)
  • Is this advisable or an anti-pattern ? In that case which JSON Schema structure would be more advisable for my problem ?

I believe something like this would be nice to avoid any schema definitions duplication.

Konrad Rudolph
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slymore
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    I don't know if the Python `jsonschema` package supports this, but many JSON Schema implementations do. However, I do know that that package doesn't support above draft-07 and the example you give is for draft 2020-12. – Jason Desrosiers Jun 24 '21 at 19:18
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    Caution: With this schema I believe it will (falsely) validate any objects that have additional arbitrary properties. You might want to test that. It's a common issue when using `allOf` – Robert Sep 14 '21 at 11:55
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    I share your desire to have a single file and validate multiple requests / objects from it. Check out this answer: https://stackoverflow.com/questions/8179137/how-to-manage-multiple-json-schema-files – Robert Sep 14 '21 at 11:56

0 Answers0