d3.js Dispatching Events with d3.dispatch


  • d3.dispatch - create a custom event dispatcher.
  • dispatch.on - register or unregister an event listener.
  • dispatch.copy - create a copy of a dispatcher.
  • dispatch.call - dispatch an event to registered listeners.
  • dispatch.apply - dispatch an event to registered listeners.


Dispatching is a convenient mechanism for separating concerns with loosely-coupled code: register named callbacks and then call them with arbitrary arguments. A variety of D3 components, such as d3-request, use this mechanism to emit events to listeners. Think of this like Node’s EventEmitter, except every listener has a well-defined name so it’s easy to remove or replace them.

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