barracks

barracks

Event dispatcher for the flux architecture. Provides event composition through this.waitFor() and checks for circular dependencies with a small interface of only 3 functions.

╔═════╗        ╔════════════╗       ╔════════╗       ╔═════════════════╗
║ API ║<──────>║ Middleware ║──────>║ Stores ║──────>║ View Components ║
╚═════╝        ╚════════════╝       ╚════════╝       ╚═════════════════╝
                     ^                                        │
                     │                                        │
               ╔════════════╗                                 │
               ║ Dispatcher ║                                 │
               ╚════════════╝                                 │
                     ^                                        │
                     └────────────────────────────────────────┘

Installation

$ npm i --save barracks

Overview

var barracks = require('barracks');

// Initialize dispatcher.

var dispatcher = barracks({
  users: {
    add: function(next) {
      console.log(user + ' got added');
      next();
    }
  courses: {
    get: function(next) {
      console.log('Get ' + this.payload);
      next();
    },
    set: function(next) {
      console.log('Set ' + this.payload);
      next();
    }
  }
});

// Dispatch an event.

dispatcher('users_add', 'Loki');
// => 'Loki got added'

API

dispatcher = barracks(actions)

Initialize a new barracks instance. The actions object should contain functions, namespaced at most one level deep. Returns a function.

// Initialize without namespaces.

var dispatcher = barracks({
  user: function() {},
  group: function() {}
});

// Initialize with namespaces.

var dispatcher = barracks({
  users: {
    add: function() {},
    remove: function() {}
  },
  courses: {
    get: function() {},
    put: function() {}
  }
});

dispatcher(action, data)

barracks() returns a dispatcher function which can be called to dispatch an action. By dispatching an action you call the corresponding function from the dispatcher and pass it data. You can think of it as just calling a function.

In order to access namespaced functions you can delimit your string with underscores. So to access courses.get you'd dispatch the string courses_get.

// Call a non-namespaced action.
dispatcher('group', [123, 'hello']);

// Call a namespaced action.
dispatcher('users_add', {foo: 'bar'});

ctx.waitFor(action)

Execute another function within the dispatcher before proceeding. Registered callbacks are always bound to the scope of the dispatcher, so you can just call this.waitFor to access the function from within a registered callback.

In the example below users_initalize will delegate execution to user_add and user_listen before proceeding to execute its own code.

var userStore = require('simple-store')('user');
var socket = require('sockjs-client');
var request = require('request');

// Initialize dispatcher.

var dispatcher = barracks({
  users: {
    initialize: function(next) {
      var arr = ['user_add', 'user_listen'];
      this.waitFor(arr, function() {
        console.log('initialized');
        next();
      });
    },
    add: function(next) {
      request('myapi.co/api/users', function(err, res) {
        userStore.set(res);
        next();
      });
    },
    listen: function(next) {
      var sock = new socket('myapi.co/api/socket');
      sock.onMessage(console.log);
      next();
    }
  }
});

// Initialize the users store.

dispatcher('users_initialize');

ctx.payload

ctx.payload contains the data provided by dispatcher().

var dispatcher = barracks({
  users: {
    init: function(next) {
      console.log(this.payload);
    }
  }
});

// Initialize the users store.

dispatcher('users_init', 'fooBar');
// -> console.log: 'fooBar'

ctx.locals=

this.locals is shared between all (delegated) function calls and acts as the location to share data between function calls. For example when you retrieve a token from a store and want to make it available to all subsequent functions.

The payload provided by dispatcher() is available under this.locals.payload.

var request = require('request');

// Initialize dispatcher.

var dispatcher = barracks({
  users: {
    add: function(next) {
      request('myapi.co/api/auth', function(err, res) {
        this.locals.token = res.token;
        next();
      });
    },
    fetch: function(next) {
      this.waitFor(['user_add'], function() {
        var url = 'myapi.co/me?token=' + this.locals.token;
        request(url, handleRequest);
      });

      function handleRequest(err, res) {
        console.log(res);
        next();
      }
    }
  }
});

// Get user data from server.

dispatcher('user_fetch');

License

MIT © Yoshua Wuyts