hapi-swagger

A swagger documentation UI generator plugin for hapi

hapi-swagger

This is a Swagger UI plug-in for HAPI v8. When installed it will self document HTTP API interface in a project.

You can add the module to your HAPI using npm:

$ npm install hapi-swagger --save

In the .js file where you create the HAPI server object add the following code after you have created the server object:

var pack = require('../package'),
    swaggerOptions = {
        basePath: 'http://localhost:8000',
        apiVersion: pack.version
    };

server.register({
        register: require('hapi-swagger'),
        options: swaggerOptions
    }, function (err) {
        if (err) {
            server.log(['error'], 'hapi-swagger load error: ' + err)
        }else{
            server.log(['start'], 'hapi-swagger interface loaded')
        }
    });

As a project may be a mixture of web pages and API endpoints you need to tag the routes you wish Swagger to document. Simply add the tags: ['api'] property to the route object for any endpoint you want documenting.

You can even specify more tags and then later generate tag-specific documentation. If you specify tags: ['api', 'foo'], you can later use /documentation?tags=foo to load the documentation on the HTML page (see next section).

{
    method: 'GET',
    path: '/todo/{id}/',
    config: {
        handler: handlers.mapUsername,
        description: 'Get todo',
        notes: 'Returns a todo item by the id passed in the path',
        tags: ['api'],
        validate: {
            params: {
                username: Joi.number()
                        .required()
                        .description('the id for the todo item'),
            }
        }
    },
}

The plugin adds a page into your site with the route /documentation. This page contains Swaggers UI to allow users to explore your API. You can also build custom pages on your own URL paths if you wish, see: "Adding interface into a page"

The plugin adds all the resources needed to build the interface into your any page in your project. All you need to do is add some javascript into the header of a web page and add two elements into the HTML where you wish it to render. The example be-more-hapi project makes use of a custom page where the interface is used with other elements.

The all the files in the URLs below are added by the plugin, but you must server the custom page as template using reply.view().

<link href='https://fonts.googleapis.com/css?family=Droid+Sans:400,700' rel='stylesheet' type='text/css'/>
<link href='{{hapiSwagger.endpoint}}/swaggerui/css/highlight.default.css' media='screen' rel='stylesheet' type='text/css'/>
<link href='{{hapiSwagger.endpoint}}/swaggerui/css/screen.css' media='screen' rel='stylesheet' type='text/css'/>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/shred.bundle.js' 'type=text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/jquery-1.8.0.min.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/jquery.slideto.min.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/jquery.wiggle.min.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/jquery.ba-bbq.min.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/handlebars-1.0.0.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/underscore-min.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/backbone-min.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/swagger.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/swagger-ui.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/swaggerui/lib/highlight.7.3.pack.js' type='text/javascript'></script>
<script src='{{hapiSwagger.endpoint}}/custom.js' type='text/javascript'></script>
<script type="text/javascript">
  $(function () {
    window.swaggerUi = new SwaggerUi({
      url: window.location.protocol + '//' + window.location.host + '{{hapiSwagger.endpoint}}',
      dom_id: "swagger-ui-container",
      supportedSubmitMethods: ['get', 'post', 'put', 'delete'],
      onComplete: function(swaggerApi, swaggerUi){
        log("Loaded SwaggerUI")
        $('pre code').each(function(i, e) {
            hljs.highlightBlock(e)
        });
        $('.response_throbber').attr( 'src', '{{hapiSwagger.endpoint}}/swaggerui/images/throbber.gif' );
      },
      onFailure: function(data) {
        log("Unable to Load SwaggerUI");
      },
      docExpansion: "list"
    });
    window.swaggerUi.load();
  });
</script>

If you want to generate tag-specific documentation, you should change the URL from

url: window.location.protocol + '//' + window.location.host + '{{hapiSwagger.endpoint}}',

to:

url: window.location.protocol + '//' + window.location.host + '{{hapiSwagger.endpoint}}?tags=foo,bar,baz',

This will load all routes that have one or more of the given tags (foo or bar or baz). More complex use of tags include:

?tags=mountains,beach,horses
this will show routes WITH 'mountains' OR 'beach' OR 'horses'

?tags=mountains,beach,+horses
this will show routes WITH ('mountains' OR 'beach')  AND 'horses'

?tags=mountains,+beach,-horses
this will show routes WITH 'mountains' AND 'beach' AND NO 'horses'

Place the HTML code below into the body fo web page where you wish the interface to render

<section id="swagger">
    <h1 class="entry-title api-title">API</h1>
    <div id="message-bar" class="swagger-ui-wrap"></div>
    <div id="swagger-ui-container" class="swagger-ui-wrap"></div>
</section>

There are number of options for advance use case. In most case you should only have to provide the apiVersion and basePath.

  • apiVersion: string The version of your API
  • basePath: string The base URL of the API i.e. http://localhost:3000
  • documentationPath: string The path of the documentation page - default: /documentation,
  • enableDocumentationPage: boolean Enable the the documentation page - default: true,
  • endpoint: string the JSON endpoint that descibes the API - default: /docs
  • pathPrefixSize: number Selects what segment of the URL path is used to group endpoints - default: 1
  • payloadType: string Weather accepts json or form parameters for payload - default: json
  • produces: array The output types from your API - the default is: ['application/json']
  • authorizations: object Containing swagger authorization objects, the keys mapping to HAPI auth strategy names. No defaults are provided.
  • info: a swagger info object with metadata about the API.
    • title string Required. The title of the application
    • description string Required. A short description of the application
    • termsOfServiceUrl string A URL to the Terms of Service of the API
    • contact string An email to be used for API-related correspondence
    • license string The license name used for the API
    • licenseUrl string A URL to the license used for the API

HAPI allow you to define a response object for an API endpoint. The response object is used by HAPI to both validation and description the output of an API. It uses the same JOI validation objects to describe the input parameters. The plugin turns these object into visual description and examples in the Swagger UI.

An very simple example of the use of the response object:

var responseModel = hapi.types.object({
    equals: Joi.number(),
}).options({
  className: 'Result'
});

within you route object ...
config: {
    handler: handlers.add,
    description: 'Add',
    tags: ['api'],
    notes: ['Adds together two numbers and return the result'],
    validate: {
        params: {
            a: Joi.number()
                .required()
                .description('the first number'),

            b: Joi.number()
                .required()
                .description('the second number')
        }
    },
    response: {schema: responseModel}
}

A working demo of more complex uses of response object can be found in the be-more-hapi project.

You can add HTTP error status codes to each of the endpoints. As HAPI routes don not directly have a property for error status codes so you need to add them the plugin configuration. The status codes need to be added as an array of objects with an error code and description:

config: {
    handler: handlers.add,
    description: 'Add',
    tags: ['api'],
    jsonp: 'callback',
    notes: ['Adds together two numbers and return the result'],
    plugins: {
        'hapi-swagger': {
            responseMessages: [
                { code: 400, message: 'Bad Request' },
                { code: 500, message: 'Internal Server Error'}
            ]
        }
    },
    validate: {
        params: {
            a: Joi.number()
                .required()
                .description('the first number'),

            b: Joi.number()
                .required()
                .description('the second number')
        }
    }
}

The plug-in has basic support for file uploads into your API's. Below is an example of a route with a file uplaod, the three important elements are:

  • payloadType: 'form' in the plugins section creates a form for upload

  • .options({ swaggerType: 'file' }) add to the payload property you wish to be file upload

  • payload cnfiguration how HAPI will process file

      {
          method: 'POST',
          path: '/store/file/',
          config: {
              handler: handlers.storeAddFile,
              plugins: {
                  'hapi-swagger': {
                      payloadType: 'form'
                  }
              },
              tags: ['api'],
              validate: {
                  payload: { 
                      file: Joi.any()
                          .options({ swaggerType: 'file' })
                          .description('json file')
                  }
              },
              payload: {
                  maxBytes: 1048576,
                  parse: true,
                  output: 'stream'
              },
              response: {schema : sumModel}
      }
    

The https://github.com/glennjones/be-more-hapi project has an example of file upload with the handler function dealing with validation, sch as filetype and schema validation.

A common issue with the use of headers is that you may only want to validate some of the headers sent in a request and you are not concerned about other headers that maybe sent also. You can use JOI .unknown() to allow any all other headers to be sent without validation errors.

validate: {
    params: {
        a: Joi.number()
            .required()
            .description('the first number'),

        b: Joi.number()
            .required()
            .description('the second number')
    },
    headers: Joi.object({
         'authorization': Joi.string().required()
    }).unknown()
}

The project has a small number integration and unit tests. To run the test within the project type the following command.

$ mocha --reporter list

If you are considering sending a pull request please add tests for the functionality you add or change.

I would like to thank Brandwatch who allow me to open this code up as part of the work on this plugin was done during a contract with them.

  • jlewark (https://github.com/jlewark)
  • ivorothschild (https://github.com/ivorothschild)
  • Joshua McGinnis (https://github.com/joshua-mcginnis)
  • David Waterston (https://github.com/davidwaterston)
  • Jozz (https://github.com/jozzhart)
  • John Oliva (https://github.com/joliva)
  • thiagogalesi4e (https://github.com/thiagogalesi4e)
  • HughePaul (https://github.com/HughePaul)
  • Stefan Oderbolz (https://github.com/metaodi)
  • Peter Henning (https://github.com/petreboy14)
  • Timo Behrmann (https://github.com/z0mt3c)
  • Darin Chambers (https://github.com/darinc)
  • Kentaro Wakayama (https://github.com/kwakayama)
  • John Brett (https://github.com/johnbrett)
  • Felipe Leusin (https://github.com/felipeleusin)

If you find any issue please file here on github and I will try and fix them.