OAS 3: Flasgger seems not being able to resolve *components* reference when using yml file

Using an external yml file, even if adding as suggested app['SWAGGER']['openapi'] = '3.0.2', it seems not being able to resolve the #/schemas/components reference:

My API is awesome......
---
tags:
  - My API
post:
  parameters:
    - name: user-id
      in: header
      description: Id of the user
      type: string
      required: true
  requestBody:
    required: true
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/Users'

responses:
  200:
    description: something.
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/UserData'

components:
  schemas:
    Users:
      type: object
      properties:
          property1:
              type: string 
    UserData:
      type: object
      properties:
          property2:
              type: string

.........
...............
..............

on the Swagger page i get:

Errors
Hide
Resolver error at paths./v1/notifications/compute.post.responses.200.content.application/json.schema.$ref
Could not resolve reference because of: Could not resolve pointer: /components/schemas/UserData does not exist in document

the schema referred by $ref: '#/components/schemas/Users' is not shown at all and no errors are visualized for this

I can’t type properly the tabs on here, but the indentation is ok on my side.

[lcbm]

Not working here as well ☹️

I’ll leave some information below, but LMK if there’s anything else I could provide you, or do for you, in order to further assist in the resolution of this issue 😄

Flasgger version: 0.9.5

Here are the relevant parts of code which include flasgger 👇

# __init__.py
...
def create_app():
    app = flask.Flask(__name__, instance_relative_config=False)
    mymodule.config.configure_app(app)
    flasgger.Swagger(app)
...

# config.py
...
    SWAGGER = {
        "uiversion": 3,
        "openapi": "3.0.3",
        "info": {
            "title": "My API",
            "description": "Awesome API.",
            "version": "0.1.0",
        },
        "optional_fields": ['components'],
    }
...

OpenAPI Specification yaml… response 400 (which uses components) does NOT work, while the response 500 (which has the same specification as the 400 one and doesn’t use components) works. Also, to be clear, I tried some variations of the code below. 👇

# availability_graph.yml
...
responses:
  400:
    description: Bad Request
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/Error'
  500:
    description: Internal Server Error
    content:
      application/json:
        schema:
          type: object
          properties:
            error:
              type: object
              properties:
                description:
                  schema:
                    type: string
                  description: A message which describes the error that occured
                  example: "An unexpected error occurred"
                message:
                  schema:
                    type: string
                  description: A message which describes the source of the error
                  example: "Internal server error"
                status_code:
                  schema:
                    type: integer
                  description: HTTP status code related to the error
                  example: 500
components:
  schemas:
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            description:
              schema:
                type: string
              description: A message which describes the error that occured
              example: "An unexpected error occurred"
            message:
              schema:
                type: string
              description: A message which describes the source of the error
              example: "Internal server error"
            status_code:
              schema:
                type: integer
              description: HTTP status code related to the error
              example: 500

Output 👇

Error 👇

[homekeeper89]

Is this solved? I had a same problem and ‘optional_fields’ is not working.