Tap into classes and methods. Aspect Oriented Programming for nodejs.

npm install tapinto
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Tap into classes and methods

dropbox = require 'dropbox'
tapinto = require 'tapinto'

class Client extends tapinto.Class(dropbox.Client)
    constructor: (@options) ->

    readfile: (path, options, callback) ->
        console.log 'Intercepted a file read'
        (error, content, stat, range) ->
            console.log 'Intercepted the results of a file read'

    #readdir: (path, options, callback) ->
    #  (error, files, dirstat, filestats) ->
    #stat: (path, options, callback) ->
    #  (error, stat, filestats) ->

module.exports =
    Client: Client

What is the problem?

Occasionally the functionality of a library is not enough, there are a few more things you want it to do. You could jump in and fork the project, but often your additions are not in line with the project direction. A mechanism to wrap and tap into the implementation of a library is useful.

Aspect Oriented Programming for nodejs.

How tapinto solves this problem

  1. Tapinto provides three mechanisms to tap into other modules: class, object and function. Only methods will be intercepted in each of these scenarios.
  2. To tap into a class inherit from tapinto.Class(dropbox.Client). Methods with the same name on your class will be called first. Return a method to tap into a callback.
  3. To tap into an object use the following: tappedobject = tapinto.Object(targetobject, yourobject).
  4. To tap into a function or method use the following: tappedmethod = tapinto.Function(targetmethod, yourmethod)
  5. A note on callbacks: tapinto will find the last parameter that is a function and use that as the callback.


  1. Simple
  2. Elegant syntax
  3. Magic is okay
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