Modella Ajax Sync Layer

Provides a AJAX Sync Layer for modella. Uses visionmedia/superagent as a request library.

Installation

modella-ajax can be used either client or server side.

To install it client side:

component install modella/modella-ajax

To install it server side:

npm install modella-ajax

Usage

As a sync layer for modella, most of modella-ajax, most of its usage is abstracted away from direct usage. You simply install the plugin and use it in modella. You must specify the API end point when using ajaxSync.

var modella  = require('modella'),
    ajaxSync = require('modella-ajax');

var User = modella('User').attr('id').attr('username');

// For a local API

User.use(ajaxSync('/users'));

// Or for a remote API

User.use(ajaxSync('http://example.com/users'));

API Expectations

modella-ajax expects you to implement a RESTful API at the end-point specified. For example in the case of User.use(ajaxSync('/users')) it would expect the following JSON API.

GET      /users       // Return a JSON list of all users
POST     /users       // Creates a new user. Returns JSON of that User

GET      /users/id    // Return a JSON user object
PUT      /users/id    // Updates an existing user. Returns JSON of that user
DELETE   /users/id    // Destroys a user

Additionally, you can "Remove all" with the following HTTP Request:

DELETE   /users/      // Destroys all users

All of these methods are optional but you will not be able to use modella's depending methods without first making an API that responds to the appropriate patterns.

Defining Alternative Routes

You can specify different routes than the defaults by passing in a second optional argument to modella-ajax.

Defaults

The default urlMap looks like the following (and maps to the API expectations above).

var urlMap = {
  create:     '',
  list:       '',
  read:       '/:primary',
  remove:     '/:primary',
  removeAll:  '',
  update:     '/:primary'
};

Overriding

If you wanted to override them, you could do so in the following way:

var ajax = require('modella-ajax')('/api/v1/users', {
  read: '/:username',
  update: '/:username',
  remove: '/:username'
});

User.use(ajax);

This would make it so that the following routes were used:

READ   ->  GET /api/v1/users/:username
UPDATE ->  PUT /api/v1/users/:username
REMOVE ->  DEL /api/v1/users/:username

Events

ajax request

Emitted before XHR request is sent.

User.on('ajax request', function(req) {
  // req is superagent request object
  req.set('Authorization', 'Bearer 13a9-34b3-a8da-c78d');
});

ajax all

Emitted before Model.all() instantiates the model instances.

User.on('ajax all', function(res) {
    var users = res.body.results;
    // Convert JSON string dates into actual dates
    users.forEach(u) {
       u.registeredAt = new Date(u.registeredAt);
    }
    res.body = users;
});

ajax get

Emitted before Model.get() instantiates the model instance.

User.on('ajax get', function(res) {
  res.body.registeredAt = new Date(res.body.registeredAt);
});

ajax removeAll

Emitted before Model.removeAll() passes response to callback.

ajax save

Emitted before model.save() passes response to callback.

ajax update

Emitted before model.update() passes response to callback.

ajax remove

Emitted before model.remove() passes response to callback.

Gotchyas

Worth noting that if you specify an attribute for READ, you must pass it in when querying. For example:

User.get({username: 'bobby'}, function(err, u) { }) ;

If a string is passed into get, it will try and replace :primary with it in the route. For Example:

User.get('1234', function(err, u) { }) ;

Wouldn't do anything because our routes wouldn't match up. You would need to specify a route of read: "/:primary".

Lastly, extra parameters passed into Model.get are not maintained unless they are in the route. For example:

User.get({username: 'tommy', age: 22})

Would still map to GET /api/v1/users/tommy.

Todo

• allow for usage of query strings w/ modellas all method