Using ENUM definitions inside of parameters (SWAGGER) - swagger

Question

I'd like to be able to use this ENUM definition:
goalStatus:
type: string
enum:
- ACTIVE
- COMPLETED
- FULFILLED
- DELETED
... inside of parameter definitions, however, I continue getting errors:
get:
description: Returns all goals for a customer
operationId: listGoals
parameters:
- name: status
in: query
description: filter by goal status
required: false
schema:
$ref: "#/definitions/goalStatus"
The error:
Swagger Error: Not a valid parameter definition

Answer 1

Unfortunately, OpenAPI 2.0 (fka. Swagger) does not define query parameters with a schema object. Therefore you cannot use a reference to your goalStatus definition (It would work for a body parameter).
What you can do is define a reusable parameter, but if you wanted to reuse this enum in some other definition, you will have to define it twice (once in definitions once in parameters). The upcoming OpenAPI 3.0 version solve this problem by allowing to define all parameters types with a schema.
Here's an example of Version 2.0 using a reusable parameter:
swagger: '2.0'
info:
version: 1.0.0
title: Parameter with enum example
paths:
/goals:
get:
description: Returns all goals for a customer
operationId: listGoals
parameters:
- $ref: "#/parameters/goalFilter"
responses:
200:
description: OK
parameters:
goalFilter:
name: status
in: query
description: filter by goal status
required: false
type: string
enum:
- ACTIVE
- COMPLETED
- FULFILLED
- DELETED