Polymorphic swagger

example.json

{
    "swagger": "2.0",
    "info": {
        "title": "Example of polymorphic models, hypothetical document recognition style",
        "version": "1.0"
    },
    "consumes": ["application/json"],
    "produces": ["application/json"],
    "paths": {
        "/analyze": {
            "post": {
                "operationId": "analyze",
                "parameters": [
                    {
                        "name": "fakeForm",
                        "in": "body",
                        "schema": {
                            "$ref": "#/definitions/AnalyzedForm"          
                        }
                    }
                ],
                "responses": {
                    "200": {
                        "description": "Successfully identied the type and contents of the document",
                        "schema": {
                            "$ref": "#/definitions/AnalyzedForm"
                        }
                    }
                }
            }
        }
    },
    "definitions": {
        "AnalyzedForm": {
            "description": "Base model for arbitrary forms. Has an untyped set of fields that can be discovered",
            "type": "object",
            "required": [
                "docType",
                "fields"
            ],
            "discriminator": "docType",
            "properties": {
                "docType": {
                    "type": "string"
                },
                "fields": {
                    "$ref": "#/definitions/FormFields"
                }
            }
        },
        "FormFields": {
            "description": "Base model for collectoin of form fields. Has no known field names",
            "type": "object",
            "additionalProperties": {
                "$ref": "#/definitions/FormField"
            }
        },
        "FormField": {
            "type": "object",
            "discriminator": "propertyType",
            "required": [
                "propertyType"
            ],
            "properties": {
                "value": {
                },
                "precision": {
                    "type": "number",
                    "minimum": 0,
                    "maximum": 1
                }
            }
        },
        "StringFormField": {
            "x-ms-discriminator-value": "string",
            "allOf": [
                {
                    "$ref": "#/definitions/FormField"
                }
            ],
            "type": "object",
            "properties": {
                "value": {
                    "type": "string"
                }
            }
        },
        "NumberFormField": {
            "x-ms-discriminator-value": "number",
            "allOf": [
                {
                    "$ref": "#/definitions/FormField"
                }
            ],
            "type": "object",
            "properties": {
                "value": {
                    "type": "number"
                }
            }
        },
        "DateFormField": {
            "x-ms-discriminator-value": "date",
            "allOf": [
                {
                    "$ref": "#/definitions/FormField"
                }
            ],
            "type": "object",
            "properties": {
                "value": {
                    "type": "string",
                    "format": "date"
                }
            }
        },
        "AnalyzedPassport": {
            "x-ms-discriminator-value": "passport",
            "allOf": [
                {
                    "$ref": "#/definitions/AnalyzedForm"
                }
            ],
            "properties": {
                "fields": {
                    "$ref": "#/definitions/AnalyzedPassportFormFields"
                }
            }
        },
        "AnalyzedPassportFormFields": {
            "allOf": [
                {
                    "$ref": "#/definitions/FormFields"
                }
            ],
            "properties": {
                "issuingCountry": {
                    "$ref": "#/definitions/StringFormField"
                },
                "firstName": {
                    "$ref":  "#/definitions/StringFormField"
                }
            }
        },
        "AnalyzedBusinessCard": {
            "x-ms-discriminator-value": "form:businesscard",
            "allOf": [
                {
                    "$ref": "#/definitions/AnalyzedForm"
                }
            ],
            "properties": {
                "fields": {
                    "$ref": "#/definitions/AnalyzedBusinessCardFields"
                }
            }
        },
        "AnalyzedBusinessCardFields": {
            "properties": {
                "companyName": {
                    "$ref": "#/definitions/StringFormField"
                },
                "phoneNumber": {
                    "$ref": "#/definitions/StringFormField"
                }
            }
        }
    }
}