SYNTH-API

Scans through the specified directory and builds endpoints that are then added to an Express app.

Each API endpoint is crafted by merely by giving it the name of the HTTP method it handles.

Synth-api is one of the major features provided by the Synth framework but is made available here for people who just want a stripped down module, and not the rest of the Synth framework (which includes support for asset compilation and more fun things).

Within your request handlers, you can either return data that will be JSONified and sent back to the client (useful for stubbing during development), a promise that will then return such data, or call the methods on the Express response object directly. See the examples below.

For each request handler you can specify services (i.e. dependencies) that should be injected.

Example Usage

app.js:

var express = require('express');
var synthApi = require('synth-api');

var app = express();
synthApi.generateHandlers({
  resourceDir: __dirname + '/resources', // This is the default, not required
  serviceDir: __dirname + '/services', // also optional
  prefix: '/api', // This is the default, not required
  app: app,
  timeout: 300
});

app.listen(80);

resources/tweets/tweets.js

// Return data directly, useful for stubbing during development
exports.getIndex = function (req, res) {
  return {
    tweets: [
      {
        message: "Fake tweet!",
        createdAt: new Date()
      }
    ]
  };
};

// Return a promise!
exports.get = function (req, res) {
  var id = req.params.id;
  return req.db.collection('tweets').findOne({
    id: id
  }).then(function (data) {
    return {
      tweet: data
    };
  });
};

// Or talk directly to Express response object
exports.post = function (req, user, db, res) {
  // db is a service declared in /services/db.js
  db.collection('tweets').insert({
    message: req.body.message,
    createdAt: new Date(),
    user_id: user.id
  }, function (err, data) {
    if (err) {
      res.status(500).send("Something went wrong: " + err.message);
    } else {
      res.send(data);
    }
  });
};

services/db.js

var db = require('promised-mongo')('localhost');
exports.db = function () {
  return db;
};

exports.user = function (db, req) {
  return db.collections('users').find({
    username: req.get('X-username'),
    password: hashPassword( req.get('X-password') )
  });
};

The above will create request handlers for the following routes:

• GET /api/tweets
• GET /api/tweets/:id
• POST /api/tweets

You can also create nested resources, handlers for PUT and DELETE, as well as custom actions. Learn more at (synthjs.com)[http://www.synthjs.com/docs/#creating-api-endpoints]

generateHandlers(options)

Options

An object with the following keys (all are optional).

option	Type	Default	What it does
prefix	String	'/api'	Specifies what should precede the resource name for the generated routes.
resourceDir	String	process.cwd() + '/resources'	The directory to look into for generating the API endpoints.
app	ExpressApp	null	If given an Express app, it will have the API and view endpoints automatically attached.
timeout	Number	5000	Time (in milliseconds) before an error response is returned to the client instead of the expected result.
catchAll	Function	null	An optional Express style request handler to handle any requests to the api path that are not handled (regardless of HTTP method). Can be used to return a custom 404 error. Note: This function should not return data or a promise. It should use the Express response object directly.

Returns

generateHandlers() returns an object with a 'handlers' key, which is an array of all the API handlers generated.

Each handler object contains the following keys:

• file - String - Path to the js file that the API handler was found in.
• method - String - The HTTP method that this handler respnds to. e.g. 'get', 'post', 'put', or 'delete'.
• path - String - The URL path that the endpoint responds to. e.g. '/api/tweets'
• isCustom - Boolean - Whether this handler is a custom method. This is good to know so that you register it before the non-custom methods. For example, you want '/api/tweets/favorites' to be registered with your Express apps before '/api/tweets/:id'.
• funcName - String - The name of function. e.g. 'getIndex'
• resources - Array[String] - The list of resources that this handler is a child of. e.g. the handler at '/api/tweets/1234/comments' would have a resources array of ['tweets', 'comments'].

Defining API endpoints

For this, just check out the existing Synth Documentation.

Defining Services

When initializing synth-api, you can specify the directory that it should recursively parse. All JavaScript and CoffeeScript files will be parsed and any publicly exposed functions will be registered as services.

API endpoints can depend on any registered service. Services can then depend on other services.

Using Services

To use a service, just specify it as a parameter and you're done! The name of the parameter tell synth-api which service should be used to satisfy it, the order of both the API endpoint and service parameters don't matter.

e.g.

exports.post = function (req, user, db, params) { … };
// is the same as: 
exports.post = function (user, params, db, req) { … };
// (note the different order of parameters)

License

MIT

Credit

• This project was created by Jon Abrams (Twitter | GitHub).