claudia-api-builder

#Claudia API Builder

This utility simplifies Node.js Lambda - API Gateway handling.

• can process multiple AWS API Gateway calls from a single Lambda function in Node.js, so that
  you can develop and deploy an entire API simpler and avoid inconsistencies.
• can work with synchronous responses or promises, so you can develop easier
• any exceptions or promise rejections are automatically reported to Lambda as errors
• any synchronous responses or promise resolutions are automatically reported to Lambda as results

The API builder is designed to work with Claudia, and add minimal overhead to client projects.

API definition syntax

An instance of the Claudia API Builder should be used as the module export from your API module. You can create a new API simply by instantiating a new ApiBuilder, then defining HTTP handlers for paths by calling .get, .put, and .post. For example, the following snippet creates a single handler for a GET call to /greet, responding with a parameterised message:

var ApiBuilder = require('claudia-api-builder'),
	api = new ApiBuilder(),
	superb = require('superb');

module.exports = api;

api.get('/greet', function (request) {
	'use strict';
	return request.queryString.name + ' is ' + superb();
});

For a more detailed example, see the Web API Example project.

The Request Object

Claudia will automatically bundle all the parameters and pass it to your handler, so you do not have to define request and response models. The request object passed to your handler contains the following properties:

• queryString: a key-value map of query string arguments
• env: a key-value map of the API Gateway stage variables (useful for storing resource identifiers and access keys)
• headers: a key-value map of all the HTTP headers posted by the client
• post: in case of a FORM post (application/x-form-www-urlencoded), a key-value map of the values posted
• body: in case of an application/json POST or PUT, the body of the request, parsed as a JSON object

Responding to requests

You can either respond synchronously (just return a value, as above), or respond with a Promise. In that case, the lambda function will wait until the Promise resolves or rejects before responding. Please note that AWS currently uses Node.js 10.0.36, which does not include the standard Promise library, so you need to include a third party one. API Builder just checks for the .then method, so it should work with any A+ Promise library.