Kalamata

Fully extensible Node.js REST API framework for Bookshelf.js and Express

Try the sample app kalamata-sample

Install

cd into your project and npm install kalamata

What it is

Kalamata helps you build REST APIs that run on Express. It creates some standard CRUD endpoints for you, and allows you to extend these with your application specific logic.

How it works

Lets say you have a Bookshelf model called User

var User = bookshelf.Model.extend({
    tableName: 'users'
});

You can use Kalamata to expose this model to your API

// set up express and kalamata
var app = require('express')();
var kalamata = require('kalamata');
var api = kalamata(app);

// expose the User model
api.expose(User);

// tell express to listen for incoming requests
app.listen(8080, function() {
    console.log('Server listening on port 8080');
});

which will create these endpoints

| Method | URL | Action | | :----- | :------------| :---------------------------- | | GET | /users | Get all users | | GET | /users/:id | Get a user by id | | POST | /users | Create a new user | | PUT | /users/:id | Update an existing user | | DELETE | /users/:id | Delete an existing user |

Extending the default endpoints

You can extend the default endpoints by modifying data before or after it is saved, using before and after hooks. These give you access to the Express request and response objects, and the Bookshelf model instance.

Some examples:

/*
 * function executes on PUT `/users/:id`
 * before updated user data is saved
 */
api.beforeUpdateUser(function(req, res, user) {
    // set a propety before user is saved
    user.set('updated_on', Date.now());
});

/*
 * function executes on GET `/users`
 * before the collection of users is fetched
 */
api.beforeGetUsers(function(req, res, user) {
    // add a where clause to execute when fetching users
    user.where({ deleted:false });
});

/*
 * function executes on GET `/users/:id`
 * after a user is fetched
 */
api.afterGetUser(function(req, res, user) {
    if(!isAuthenticatedUser(user)) {
        // override the default user data response
        res.send({ error: 'access denied' });
    }
});

Configuring the API

Initialize kalamata(expressApp, [options])

apiRoot option sets a prefix for all API endpoints

/*
 * prefixes all endpoints with `/api/v1`,
 * for example `/api/v1/users`
 */
var api = kalamata(app, { apiRoot: '/api/v1' });

expose expose(bookshelfModel, [options])

endpointName option sets the name of the endpoint.

Defaults to the bookshelf model's tableName property.

// sets endpoints up on `/allusers`
api.expose(User, { endpointName: 'allusers' });

identifier option sets the name of the identifier param

Defaults to id

/*
 * when identifier is set to `user_id`,
 * a request to `/users/32` will fetch
 * the user with `user_id = 32`
 */
api.expose(User, { identifier: 'user_id' });

modelName option sets the name of the model

Defaults to the endpoint name capitalized with the s removed (users -> User)

collectionName options sets the name for a collection of model instances

Defaults to the endpoint name capitalized (users -> Users)

Default Endpoints

Calling expose on a model will create a set of default CRUD endpoints. Here are the default endpoints, assuming that api.expose(User) was called.

GET /users

Gets an array of users

/*
 * GET `/users`
 */

// response:
[
    { "id": 1, "name": "user1" },
    { "id": 2, "name": "user2" },
    { "id": 3, "name": "user3" }
]

where parameter includes a where clause in the query

/users?where={name:"user2"}

Expects the same parameters as the bookshelf.js where method

load parameter will load related models and include them in the response

/users?load=orders,favorites

Expects a comma delimited string of relations. Calls the bookshelf.js load method method with an array of relations.

GET /users/:identifier

Gets a user

/*
 * GET `/users/2`
 */

// response:
{ "id": 2, "name": "user2" }

load parameter will load related models and include them in the response

/user/2?load=orders,favorites

Expects a comma delimited string of relations. Calls the bookshelf.js load method method with an array of relations.

POST /users

Creates a user

/*
 * POST `/users` { "name": "user4" }
 */

// response:
{ "id": 4, "name": "user4" }

PUT /users/:identifier

Modifies a user

/*
 * PUT `/users/2` { "name": "user2 MODIFIED" }
 */

// response:
{ "id": 2, "name": "user2 MODIFIED" }

DELETE /users/:identifier

Deletes a user

/*
 * DELETE `/users/3`
 */

// response:
true

GET /users/:identifier/things

Gets an array of things related to a user

/*
 * GET `/users/2/things`
 */

// response:
[{ "id": 3, "name": "thing3" },{ "id": 4, "name": "thing4" }]

POST /users/:identifier/things

Relates a thing to a user

/*
 * POST `/users/2/things` { "id": "3" }
 */

// response:
{}

Hooks

Hooks let you extend and override default endpoint behaviors.

before hooks are executed before the default database action, such as fetch, save, or delete. after hooks are executed after all database actions are complete.

Hook names are generated based on endpoint configurations. This list is based on a /users endpoint where modelName = User and collectionName = Users

| Hook Name | Request | Arguments | | :-------------------------| :------------------------ | :------------------------------------ | | beforeGetUsers | GET /users | [req, res, userModel] | | afterGetUsers | GET /users | [req, res, userCollection] | | beforeGetUser | GET /users/:id | [req, res, userModel] | | afterGetUser | GET /users/:id | [req, res, userModel] | | beforeCreateUser | POST /users | [req, res, userModel] | | afterCreateUser | POST /users | [req, res, userModel] | | beforeUpdateUser | PUT /users/:id | [req, res, userModel] | | afterUpdateUser | PUT /users/:id | [req, res, userModel] | | beforeDeleteUser | DELETE /users/:id | [req, res, userModel] | | afterDeleteUser | DELETE /users/:id | [req, res, userModel] | | beforeGetRelatedThings | GET /users/:id/things | [req, res, thingModel] | | afterGetRelatedThings | GET /users/:id/things | [req, res, thingsCollection] | | beforeRelatedThing | POST /users/:id/things | [req, res, userModel] | | afterRelateThing | POST /users/:id/things | [req, res, userModel, thingModel] |

req and res are an Express request and response

userModel is an instance of a bookshelf model

userCollection is an instance of a bookshelf collection

Adding hooks

api.beforeCreateUser(function(req, res, user) {
    // do stuff before the user is created
});

api.afterCreateUser(function(req, res, user) {
    // do stuff after the user is created
});

What hooks can do

Because you have the full power of Express and Bookshelf within your hooks, you have total control over how the Kalamata endpoints behave. Here are some examples:

Manipulating data

If the server receives a POST /users { "name":"Joey" } request:

/*
 * The user model can be manipulated before it is saved.
 *
 * When this hook is finished executing,
 * `{ "name":"Joey McGee" }` will be saved
 *
 */
api.beforeCreateUser(function(req, res, user) {
    var userName = user.get('name');
    user.set({name:userName + ' McGee'});
});

/*
 * After the user is created, the response can be manipulated.
 *
 * When this hook is finished executing, the server will
 * respond with `{ "name":"Joey", "lastName":"McGee" }`
 *
 * The changes to the user will not be saved, because this hook
 * is executed after the user is saved
 *
 */
api.afterCreateUser(function(req, res, user) {
    var nameSplit = user.get('name').split(' ');
    user.set({
        name: nameSplit[0],
        lastName: nameSplit[1]
    });
});

Cancelling default actions

If the server receives a GET /user/5 request, but you don't want to respond with the user's data:

/*
 * Send a response from the before hook
 *
 * Once a response is sent, Kalamata will not execute
 * any of the default actions, including after hooks.
 *
 */
api.beforeGetUser(function(req, res, user) {
    if(user.get('id') == 5) {
        res.send({ error: "access denied" });
    }
});
api.afterGetUser(function(req, res, user) {
    // will not be executed on requests for `user/5`
});

Overriding default actions

If the server receives a DELETE /user/5 request, Kalamata will call user.destroy() by default. You can override this default behavior by returning a promise from the before hook:

/*
 * Call a function that returns a promise, and have the
 * hook function return the result of that promise
 *
 * Kalamata will not execute the default action,
 * which in this case would have been `user.destroy()`
 *
 * Flag the user as deleted with a `deleted=true` property
 */
api.beforeDeleteUser(function(req, res, user) {
    return user.save({ deleted: true });
});