flask-swagger

A swagger 2.0 spec extractor for flask


License
MIT
Install
conda install -c anaconda flask-swagger

Documentation

flask-swagger

A Swagger 2.0 spec extractor for Flask

You can now specify base path for yml files:

app = Flask(__name__)

@app.route("/spec")
def spec():
    base_path = os.path.join(app.root_path, 'docs')
    return jsonify(swagger(app), from_file_keyword="swagger_from_file", base_path=base_path)

and use relative paths:

@app.route('/test', methods=['POST'])
def login():
    """
    swagger_from_file: test.yml
    """

Install:

pip install flask-swagger

Flask-swagger provides a method (swagger) that inspects the Flask app for endpoints that contain YAML docstrings with Swagger 2.0 Operation objects.

class UserAPI(MethodView):

    def post(self):
        """
        Create a new user
        ---
        tags:
          - users
        definitions:
          - schema:
              id: Group
              properties:
                name:
                 type: string
                 description: the group's name
        parameters:
          - in: body
            name: body
            schema:
              id: User
              required:
                - email
                - name
              properties:
                email:
                  type: string
                  description: email for user
                name:
                  type: string
                  description: name for user
                address:
                  description: address for user
                  schema:
                    id: Address
                    properties:
                      street:
                        type: string
                      state:
                        type: string
                      country:
                        type: string
                      postalcode:
                        type: string
                groups:
                  type: array
                  description: list of groups
                  items:
                    $ref: "#/definitions/Group"
        responses:
          201:
            description: User created
        """
        return {}

Flask-swagger supports docstrings in methods of MethodView classes (ala Flask-RESTful) and regular Flask view functions.

Following YAML conventions, flask-swagger searches for ---, everything preceding is provided as summary (first line) and description (following lines) for the endpoint while everything after is parsed as a swagger Operation object.

In order to support inline definition of Schema objects in Parameter and Response objects, flask-swagger veers a little off from the standard. We require an id field for the inline Schema which is then used to correctly place the Schema object in the Definitions object.

Schema objects can be defined in a definitions section within the docstrings (see group object above) or within responses or parameters (see user object above). We also support schema objects nested within the properties of other Schema objects. An example is shown above with the address property of User.

If you don't like to put YAML on docstrings you can put the same content in an external file.

file.yml

Create a new user
---
tags:
  - users
definitions:
  - schema:
      id: Group
      properties:
        name:
         type: string
         description: the group's name
parameters:
  - in: body
    name: body
    schema:
      id: User
      required:
        - email
        - name
      properties:
        email:
          type: string
          description: email for user
        name:
          type: string
          description: name for user
        address:
          description: address for user
          schema:
            id: Address
            properties:
              street:
                type: string
              state:
                type: string
              country:
                type: string
              postalcode:
                type: string
        groups:
          type: array
          description: list of groups
          items:
            $ref: "#/definitions/Group"
responses:
  201:
    description: User created

and point to it in your docstring.

class UserAPI(MethodView):

    def post(self):
        """
        Create a new user

        blah blah

        swagger_from_file: path/to/file.yml

        blah blah
        """
        return {}

Note that you can replace swagger_from_file by another keyword. Supply your chosen keyword as an argument to swagger.

To expose your Swagger specification to the world you provide a Flask route that does something along these lines

from flask import Flask, jsonify
from flask_swagger import swagger

app = Flask(__name__)

@app.route("/spec")
def spec():
    return jsonify(swagger(app))

Note that the Swagger specification returned by swagger(app) is as minimal as it can be. It's your job to override and add to the specification as you see fit.

@app.route("/spec")
def spec():
    swag = swagger(app)
    swag['info']['version'] = "1.0"
    swag['info']['title'] = "My API"
    return jsonify(swag)

Swagger-UI

Swagger-UI is the reason we embarked on this mission to begin with, flask-swagger does not however include Swagger-UI. Simply follow the awesome documentation over at https://github.com/swagger-api/swagger-ui and point your swaggerUi.url to your new flask-swagger endpoint and enjoy.

flaskswagger Command

This package now comes with a very simple command line interface: flaskswagger. This command can be used to build and update swagger specs for your flask apps from the command line or at build time.

flaskswagger -h
usage: flaskswagger [-h] [--template TEMPLATE] [--out-dir OUT_DIR]
                    [--definitions DEFINITIONS] [--host HOST]
                    [--base-path BASE_PATH] [--version VERSION]
                    app

positional arguments:
  app                   the flask app to swaggerify

optional arguments:
  -h, --help            show this help message and exit
  --template TEMPLATE   template spec to start with, before any other options
                        or processing
  --out-dir OUT_DIR     the directory to output to
  --definitions DEFINITIONS
                        json definitions file
  --host HOST
  --base-path BASE_PATH
  --version VERSION     Specify a spec version

For example, this can be used to build a swagger spec which can be served from your static directory. In the example below, we use the manually created swagger.json.manual as a template, and output to the static/ directory.

flaskswagger server:app --template static/swagger.json.manual --out-dir static/

Also, you can ask flaskswagger to add host and basePath to your swagger spec:

flaskswagger server:app --host localhost:5000 --base-path /v1

Acknowledgements

Flask-swagger builds on ideas and code from flask-sillywalk and flask-restful-swagger

Notable forks

Flasgger