grape-swagger

Table of Contents

• What is grape-swagger?
• Related Projects
• Compatibility
• Swagger-Spec
• Installation
• Usage
• Model Parsers
• Configure
• Routes Configuration
• Using Grape Entities
• Securing the Swagger UI
• Example
• Rake Tasks

What is grape-swagger? <a name="what"></a>

The grape-swagger gem provides an autogenerated documentation for your Grape API. The generated documentation is Swagger-compliant, meaning it can easily be discovered in Swagger UI. You should be able to point the petstore demo to your API.

This screenshot is based on the Hussars sample app.

Related Projects <a name="related"></a>

• Grape
• Grape Swagger Entity
  • Grape Entity
• Grape Swagger Representable
• Swagger UI

Compatibility <a name="version"></a>

The following versions of grape, grape-entity and grape-swagger can currently be used together.

grape-swagger	swagger spec	grape	grape-entity	representable
0.10.5	1.2	>= 0.10.0 ... <= 0.14.0	< 0.5.0	n/a
0.11.0	1.2	>= 0.16.2	< 0.5.0	n/a
0.25.2	2.0	>= 0.14.0 ... <= 0.18.0	<= 0.6.0	>= 2.4.1
0.26.0	2.0	>= 0.16.2 ... <= 1.1.0	<= 0.6.1	>= 2.4.1
0.27.0	2.0	>= 0.16.2 ... <= 1.1.0	>= 0.5.0	>= 2.4.1
0.32.0	2.0	>= 0.16.2	>= 0.5.0	>= 2.4.1
0.34.0	2.0	>= 0.16.2 ... < 1.3.0	>= 0.5.0	>= 2.4.1
>= 1.0.0	2.0	>= 1.3.0	>= 0.5.0	>= 2.4.1
>= 2.0.0	2.0	>= 1.7.0	>= 0.5.0	>= 2.4.1

Swagger-Spec <a name="swagger-spec"></a>

Grape-swagger generates documentation per Swagger / OpenAPI Spec 2.0.

<!-- validating it with: http://bigstickcarpet.com/swagger-parser/www/index.html -->

Installation <a name="install"></a>

Add to your Gemfile:

gem 'grape-swagger'

Upgrade

Please see UPGRADING when upgrading from a previous version.

Usage <a name="usage"></a>

Mount all your different APIs (with Grape::API superclass) on a root node. In the root class definition, include add_swagger_documentation, this sets up the system and registers the documentation on '/swagger_doc'. See example/config.ru for a simple demo.

require 'grape-swagger'

module API
  class Root < Grape::API
    format :json
    mount API::Cats
    mount API::Dogs
    mount API::Pirates
    add_swagger_documentation
  end
end

To explore your API, either download Swagger UI and set it up yourself or go to the online swagger demo and enter your localhost url documentation root in the url field (probably something in the line of http://localhost:3000/swagger_doc).

Model Parsers <a name="model_parsers"></a>

Since 0.21.0, Grape::Entity is not a part of grape-swagger, you need to add grape-swagger-entity manually to your Gemfile. Also added support for representable via grape-swagger-representable.

# For Grape::Entity ( https://github.com/ruby-grape/grape-entity )
gem 'grape-swagger-entity', '~> 0.3'
# For representable ( https://github.com/apotonick/representable )
gem 'grape-swagger-representable', '~> 0.2'

If you are not using Rails, make sure to load the parser inside your application initialization logic, e.g., via require 'grape-swagger/entity' or require 'grape-swagger/representable'.

Custom Model Parsers

You can create your own model parser, for example for roar.

module GrapeSwagger
  module Roar
    class Parser
      attr_reader :model
      attr_reader :endpoint

      def initialize(model, endpoint)
        @model = model
        @endpoint = endpoint
      end

      def call
        # Parse your model and return hash with model schema for swagger
      end
    end
  end
end

Then you should register your custom parser.

GrapeSwagger.model_parsers.register(GrapeSwagger::Roar::Parser, Roar::Decorator)

To control model parsers sequence, you can insert your parser before or after another parser.

insert_before

GrapeSwagger.model_parsers.insert_before(GrapeSwagger::Representable::Parser, GrapeSwagger::Roar::Parser, Roar::Decorator)

insert_after

GrapeSwagger.model_parsers.insert_after(GrapeSwagger::Roar::Parser, GrapeSwagger::Representable::Parser, Representable::Decorator)

As we know, Roar::Decorator uses Representable::Decorator as a superclass, this allows to avoid a problem when Roar objects are processed by GrapeSwagger::Representable::Parser instead of GrapeSwagger::Roar::Parser.

CORS

If you use the online demo, make sure your API supports foreign requests by enabling CORS in Grape, otherwise you'll see the API description, but requests on the API won't return. Use rack-cors to enable CORS.

require 'rack/cors'
use Rack::Cors do
  allow do
    origins '*'
    resource '*', headers: :any, methods: [ :get, :post, :put, :delete, :options ]
  end
end

Alternatively you can set CORS headers in a Grape before block.

before do
  header['Access-Control-Allow-Origin'] = '*'
  header['Access-Control-Request-Method'] = '*'
end

Configure <a name="configure"></a>

• host
• base_path
• mount_path
• add_base_path
• add_root
• add_version
• doc_version
• endpoint_auth_wrapper
• swagger_endpoint_guard
• token_owner
• security_definitions
• security
• models
• tags
• hide_documentation_path
• info
• array_use_braces
• api_documentation
• specific_api_documentation
• consumes
• produces

You can pass a hash with optional configuration settings to add_swagger_documentation. The examples show the default value.

The host and base_path options also accept a proc or a lambda to evaluate, which is passed a request object:

add_swagger_documentation \
  base_path: proc { |request| request.host =~ /^example/ ? '/api-example' : '/api' }

host: <a name="host"></a>

Sets explicit the host, default would be taken from request.

add_swagger_documentation \
   host: 'www.example.com'

base_path: <a name="base_path"></a>

Base path of the API that's being exposed, default would be taken from request.

add_swagger_documentation \
   base_path: nil

host and base_path are also accepting a proc or lambda

mount_path: <a name="mount_path"></a>

The path where the API documentation is loaded, default is: /swagger_doc.

add_swagger_documentation \
   mount_path: '/swagger_doc'

add_base_path: <a name="add_base_path"></a>

Add basePath key to the documented path keys, default is: false.

add_swagger_documentation \
   add_base_path: true # only if base_path given

add_root: <a name="add_root"></a>

Add root element to all the responses, default is: false.

add_swagger_documentation \
   add_root: true

add_version: <a name="add_version"></a>

Add version key to the documented path keys, default is: true, here the version is the API version, specified by grape in path

add_swagger_documentation \
   add_version: true

doc_version: <a name="doc_version"></a>

Specify the version of the documentation at info section, default is: '0.0.1'

add_swagger_documentation \
   doc_version: '0.0.1'

endpoint_auth_wrapper: <a name="endpoint_auth_wrapper"></a>

Specify the middleware to use for securing endpoints.

add_swagger_documentation \
   endpoint_auth_wrapper: WineBouncer::OAuth2

swagger_endpoint_guard: <a name="swagger_endpoint_guard"></a>

Specify the method and auth scopes, used by the middleware for securing endpoints.

add_swagger_documentation \
   swagger_endpoint_guard: 'oauth2 false'

token_owner: <a name="token_owner"></a>

Specify the token_owner method, provided by the middleware, which is typically named 'resource_owner'.

add_swagger_documentation \
   token_owner: 'resource_owner'

security_definitions: <a name="security_definitions"></a>

Specify the Security Definitions Object

NOTE: Swagger-UI is supporting only implicit flow yet

add_swagger_documentation \
  security_definitions: {
    api_key: {
      type: "apiKey",
      name: "api_key",
      in: "header"
    }
  }

security: <a name="security"></a>

Specify the Security Object

add_swagger_documentation \
  security: [
    {
      api_key: []
    }
  ]

models: <a name="models"></a>

A list of entities to document. Combine with the grape-entity gem.

These would be added to the definitions section of the swagger file.

add_swagger_documentation \
   models: [
     TheApi::Entities::UseResponse,
     TheApi::Entities::ApiError
   ]

tags: <a name="tags"></a>

A list of tags to document. By default tags are automatically generated for endpoints based on route names.

add_swagger_documentation \
  tags: [
    { name: 'widgets', description: 'A description of widgets' }
  ]

hide_documentation_path: (default: true) <a name="hide_documentation_path"></a>

add_swagger_documentation \
   hide_documentation_path: true

Don't show the /swagger_doc path in the generated swagger documentation.

info: <a name="info"></a>

add_swagger_documentation \
  info: {
    title: "The API title to be displayed on the API homepage.",
    description: "A description of the API.",
    contact_name: "Contact name",
    contact_email: "Contact@email.com",
    contact_url: "Contact URL",
    license: "The name of the license.",
    license_url: "www.The-URL-of-the-license.org",
    terms_of_service_url: "www.The-URL-of-the-terms-and-service.com",
  }

A hash merged into the info key of the JSON documentation.

array_use_braces: <a name="array_use_braces"></a>

add_swagger_documentation \
  array_use_braces: true

This setting must be true in order for params defined as an Array type to submit each element properly.

params do
 optional :metadata, type: Array[String]
end

with array_use_braces: true:

metadata[]: { "name": "Asset ID", "value": "12345" }
metadata[]: { "name": "Asset Tag", "value": "654321"}

with array_use_braces: false:

metadata: {"name": "Asset ID", "value": "123456"}
metadata: {"name": "Asset Tag", "value": "654321"}

api_documentation

Customize the Swagger API documentation route, typically contains a desc field. The default description is "Swagger compatible API description".

add_swagger_documentation \
   api_documentation: { desc: 'Reticulated splines API swagger-compatible documentation.' }

specific_api_documentation

Customize the Swagger API specific documentation route, typically contains a desc field. The default description is "Swagger compatible API description for specific API".

add_swagger_documentation \
   specific_api_documentation: { desc: 'Reticulated splines API swagger-compatible endpoint documentation.' }

consumes

Customize the Swagger API default global consumes field value.

add_swagger_documentation \
   consumes: ['application/json', 'application/x-www-form-urlencoded']

produces

Customize the Swagger API default global produces field value.

add_swagger_documentation \
   produces: ['text/plain']

Routes Configuration <a name="routes"></a>

• Swagger Header Parameters
• Hiding an Endpoint
• Overriding Auto-Generated Nicknames
• Specify endpoint details
• Overriding the route summary
• Overriding the tags
• Deprecating routes
• Overriding the name of the body parameter
• Defining an endpoint as an array
• Using an options hash
• Overriding parameter type
• Overriding data type of the parameter
• Multiple types
• Array of data type
• Collection Format
• Hiding parameters
• Setting a Swagger default value