Bus

A simple, declarative event bus for typical cases.

AKA a fluid DSL on top of Emitter.

Installation

$ component install ericgj/bus

Example

  var bus = require('bus')();

  var mainPanel = MainPanel('#main');
  var sidePanel = SidePanel('#sidebar');
  var filterPanel = FilterPanel('#filter');

  logFilterEvent = function(param) {
    console.log('filter: %s', param);
  }

  /**
   *  Route 'select' events from the filterPanel to
   *  mainPanel.applyFilter and sidePanel.setFilter,
   *  and to two custom handlers
   */
  bus.route().from(filterPanel, 'select')
     .to( mainPanel, 'applyFilter' )
     .to( sidePanel, 'setFilter' )
     .handle( logFilterEvent )
     .handle( function(param) { /* some callback */ } );

  /**
   *  Or, define routes in reverse direction. Here
   *  events from sidePanel and mainPanel are routed
   *  to filterPanel.clearFilter.
   */
  bus.route().to(filterPanel, 'clearFilter')
     .from( sidePanel, 'reset' )
     .from( mainPanel, 'clear' );

  /**
   *  You can define different routes in a single call
   *  using route(), aliased as reset()
   */
  bus.route()
       .from(x,'event')
         .to(y1,'method')
         .to(y2,'method')
     .reset()
       .to(z,'method')
         .from(w1,'event')
         .from(w2,'event');

API

Bus#from(source, event)

Set the current source. If a receiver has been set, then bind the event to it.

Bus#to(receiver, method)

Set the current receiver. If a source has been set, then bind its event to the receiver.

Bus#handle(fn)

Set the current receiver to an arbitrary function rather than object + method.

Bus#route or #reset

Reset the current source and receiver, to define a new route.

Note

There are no hard dependencies, any emitter-ish object (with .on) will work as a source.

The DSL does not currently control unbinding events (.off), so if you want that, manage it in your sources, or send me a pull request for bus.off().to().from() 😉

License

MIT