chainify()

Creates an asynchronous model using asynchronous method queueing.

Core

• Futures.chainify(providers, modifiers, consumers, context) - creates an asynchronous model

  • providers - methods which provide data - must return Futures or Joins or undefined

    • function (next, params) must call next

  • modifiers - methods which use provided data and modify it - act as Sequences

    • function (next, err, data [, ...]) must call next

  • consumers - methods which use data without modifying it - act as simple callbacks

    • function (err, data [, ...])

Note: next is an instance of Futures.deliver

Example:

Let's say we want to produce a model which acts like this:

Contacts.all({httpAuth: base64("coolaj86:secret")}).limit(30).render();

The code to produce such a model might look like this:

var Contacts,
  providers,
  modifiers,
  consumers;

// Get resources from various sites
providers = {
  facebook: function (next, params) {
    var future = Futures.future();
    // make async calls to get data

    // probably best to handle errors
    // and not pass them on
    next(data);
  },
  twitter: function (next, params) {
    // same as above
  },
  all: function (next, params) {
    var join = Futures.join();
    join.add([
      providers.FacebookContacts(params),
      providers.TwitterContacts(params)
    ]);
    join.when(next);
  }
};

modifiers = {
  limit: function(next, data, params) {
    data = data.first(params);
    next(data);
  }
};

consumers = {
  render: function (data, params) {
    Template.render(data, params);
  }
};

Contacts = Futures.chainify(providers, modifiers, consumers);