How to describe this validation requirement in jsonschema? - json

Question

I want to validate my API json response like this:
{
"code": 0,
"results": [
{"type":1, "abc": 123},
{"type":2, "def": 456}
]
}
I want to validate the objects within results to have a "abc" field when its type is 1, and "def" field when its type is 2. The results may contain arbitrary number of type1 and type2 objects.
Can I specify this in jsonschema? Or must I use a generic validator for elements in results and do validation myself?

Answer 1

You can do this using the anyOf keyword.
An instance validates successfully against this keyword if it validates successfully against at least one schema defined by this keyword's value.
http://json-schema.org/latest/json-schema-validation.html#anchor85
You need to define both types of items and then use anyOf To describe the array items for "results".
{
"type": "object",
"properties": {
"code": { "type": "integer" },
"results": {
"type": "array",
"items": { "$ref": "#/definitions/resultItems" }
}
},
"definitions": {
"resultItems": {
"type": "object",
"anyOf": [
{ "$ref": "#/definitions/type1" },
{ "$ref": "#/definitions/type2" }
]
},
"type1": {
"properties": {
"type": { "enum": [1] },
"abc": { "type": "integer" }
},
"required": ["abc"]
},
"type2": {
"properties": {
"type": { "enum": [2] },
"def": { "type": "integer" }
},
"required": ["def"]
}
}
}