JsonSchema: Validate type based on value of another property

Question

I am using the following schema to validate my json:

{
    \"$schema\": \"http://json-schema.org/schema#\",
    \"title\": \" Rules\",
    \"description\": \         


        

Answer 1

The best way to solve these kinds of problems is to separate the complex validation from the rest of the schema using definitions and include it with an allOf. In this solution, I use implication to enforce the validation.

{
  "type": "object",
  "properties": {
    "rules": {
      "type": "array",
      "items": { "$ref": "#/definitions/rule" }
    }
  },
  "required": ["rules"],
  "definitions": {
    "rule": {
      "type": "object",
      "properties": {
        "precedence": { "type": "number", "minimum": 0 },
        "conditions": {
          "type": "array",
          "items": { "$ref": "#/definitions/condition" }
        }
      },
      "required": ["precedence", "conditions"]
    },
    "condition": {
      "type": "object",
      "properties": {
        "field": { "enum": ["Name", "Size"] },
        "relation": { "enum": ["is", "is not", "is not one of", "is one of"] },
        "value": { "type": ["array", "string", "number"] }
      },
      "required": ["field", "relation", "value"],
      "allOf": [{ "$ref": "#/definitions/array-condition-implies-value-is-array" }]
    },
    "array-condition-implies-value-is-array": {
      "anyOf": [
        { "not": { "$ref": "#/definitions/is-array-condition" } },
        { "$ref": "#/definitions/value-is-array" }
      ]
    }
    "is-array-condition": {
      "properties": {
        "relation": { "enum": ["is not one of", "is one of"] }
      },
      "required": ["relation"]
    },
    "value-is-array": {
      "properties": {
        "value": { "type": "array" }
      }
    }
  }
}