// Interface for controllers

var Controller = {

get: function() {}

};

// Bad: because it tightly couples the code to a specific implementation of the repo.

// Object thathas·

//var BadUserController = function () {

// this.userRepo = new UserRepoImplA();

//};

// Application code doesn't care which implementation is being used. Since the program is constructed against the interface

// it does not know or care about the implementation.

// Good: Inject the dependencies into the object using constructor injection.

// UserController has no interest in how things are implemented. It just wants to be able to call the repo's get/save methods.

// LSP - Any objects that implement an interface can be used interchangeably

// Implementation of user controller

var UserController = function(userRepo){

this.userRepo = userRepo;

};

// Implementation of matches controller

var MatchController = function(findMatchFactory) {

this.findMatchFactory = findMatchFactory;

};

MatchController.prototype = Object.create(Controller);

MatchController.prototype.findMatches = function(type, userId) {

// Get implementation for runtime type

var matcher = this.findMatchFactory.getMatchImpl(type);

return matcher.matches(userId);

};