Swagger Client Generator

Generates a client given a requests handler and a Swagger API Specification schema (which can be generated with fetch-swagger-schema: npm install -g fetch-swagger-schema; fetch-swagger-schema <api-docs url> <destination>).

This is intended to be a helper for creating swagger clients by passing in a request handler for the platform being used (e.g., you XHR request handler in browsers, and request in node). It provides robust client-side validation according to the API endpoints and converts given data into appropriate url, header, and body information to be consumed by the request handler.

Example

function requestHandler(error, request){
  if(error) return console.error(error.toString());

  var xhr = new XMLHttpRequest();
  xhr.open(request.method, request.url)

  if(request.headers){
    Object.keys(request.headers).forEach(function(header){
      xhr.setRequestHeader(header, request.headers[header]);
    });
  }

  xhr.onloadend = function(){
    request.options.callback(this.response);
  };

  xhr.send(request.body);
}

// assumes that 'schema' already exists in scope and is the schema object for
// http://petstore.swagger.wordnik.com/api/api-docs 
var api = swaggerClientGenerator(schema, requestHandler);

// for apiKey authorization use: api.auth('my-token')
// for basicAuth use: api.auth('username', 'password')
// authorization may be set for any level (api, api.resource, or api.operation)

api.pet.getPetById(2, function(response){
  console.log(response);
});

Creating a schema object

A schema is just a compilation of the Swagger Resource Listing object with each Resource object embedded directly within it. You can fetch one and save it automatically by using fetch-swagger-schema:

# install the fetch-swagger-schema tool
npm install -g fetch-swagger-schema
fetch-swagger-schema <url to a swagger api docs> <destination>
# the generated schema json file will be at <destination>

API

api = swaggerClientGenerator(schemaObject, requestHandler)

• schemaObject - A json object describing the schema (generally generated by fetch-swagger-schema).
• requestHandler - A function which accepts two parameters error and request. The error object will be a ValidationErrors object if an validation error occurs, otherwise it will be undefined. The request object is defined below.
• api - An object which can be used as the api for the given schema. The first-level objects are the resources within the schema and the second-level functions are the operations which can be performed on those resources.

api.<resource>

A map of all the resources as defined in the schema to their operation handler (e.g. api.pet).

requestHandlerResponse = api.<resource>.<operationHandler>(data, options)

This is the actual operation handler invoked by the clients (e.g., api.pet.getPetById).

The operation handler takes two parameters:

• data - A map of the operation data parameters. If the operation only has one parameter, the value may be used directly (i.e. api.pet.getPetById(1, callback) is the same as api.pet.getPetById({petId: 1}, callback)).
• options - A map of the options to use when calling the operation. This differs based on operation but it may include parameters such as contentType or accept and it commonly includes options to pass to the request handler (such as a callback function when the request completes). If options is a function, then the callback property of options will be a reference to the function for convenience (e.i. api.pet.getPetById(1, callback) is the same as api.pet.getPetById(1, { callback: callback }).

The operation handler processes the data and options, passes the processed request data to the requestHandler and returns the result of the requestHandler back to the caller. The operation handler does not process the results of the requestHandler before returning it to the caller.

url = api.<resource>.<operationHandler>.getUrl(data)

Intended for advanced use-cases. Returns the URL which would be called if the operation were to be called using this operation handler. The acceptable HTTP method to call this url can be found at api.<resource>.<operationHandler>.operation.method.

requestHandler(error, request)

The request handler is the second parameter for the swaggerClientGenerator and will be called whenever an operation is invoked. If there are any validation errors, the errors parameter be a ValidationErrors object describing the validation errors in detail.

The request object will have the following properties which should be used to issue the actual HTTP request:

• method - The HTTP method string for the operation
• url - The url string to call for the operation
• headers - A map of the request headers
• body - The body of the request
• options - Options passed in as the second parameter to the operation handler, commonly used for callbacks
• operation - The metadata of the operation being invoked
• data - The raw data used to generate the url, headers, and body
• errorTypes - A map of all possible error types which are used in the error parameter (useful for instanceof checks)

operation objects

This object, which is found in either request.operation or api.<resource>.<operationHandler>.operation contains references to the entire schema object:

• Operation - operation
• API Object - operation.apiObject
• API Declaration - operation.apiObject.apiDeclaration
• Resource Object - operation.apiObject.resourceObject
• Resource Listing- operation.apiObject.resourceObject.resourceListing

Developing

After installing nodejs execute the following:

git clone https://github.com/signalfx/swagger-ajax-client.git
cd swagger-ajax-client
npm install
npm run dev

The build engine will test and build everything, start a server hosting the example folder on localhost:3000, and watch for any changes and rebuild when nescessary.

To generate minified files in dist:

npm run dist