json schema object property constraints - jsonschema

Question

In my schema I have an array of phone objects. Each object has a "status" property, which can be one of three values: "Primary", "Active" and "Not-in-use".
I want to set the following constraint:
If the number of phone objects > 0 then exactly one must have status="Primary"
Is this possible with json schema? If so, how?

Answer 1

This schema is pretty close to what you want. The only restriction is that the "Primary" phone number needs to be the first item in the array.
You might be able to get "Primary" to be anywhere in the array with some creative use of not. I'll update the answer if I figure it out.
{
"type": "object",
"properties": {
"phoneNumbers": {
"type": "array",
"items": [{ "$ref": "#/definitions/primaryPhone" }],
"additionalItems": { "$ref": "#/definitions/additionalPhone" }
}
},
"definitions": {
"phone": {
"type": "object",
"properties": {
"label": { "type": "string" },
"number": { "type": "string" }
},
"required": ["label", "number", "status"]
},
"primaryPhone": {
"allOf": [{ "$ref": "#/definitions/phone" }],
"properties": {
"status": { "enum": ["Primary"] }
}
},
"additionalPhone": {
"allOf": [{ "$ref": "#/definitions/phone" }],
"properties": {
"status": { "enum": ["Active", "Not-in-use"] }
}
}
}
}