Java script visitor sample is not working

Question

I need to use logic like visitor pattern and I've created new sample which failed in visitor.visit(self); and I got error undefined is not a function, any idea what am I missing?

var Entity = function (file,name) {
    var self = this;
    var name;
    var type;
    var log = {};

    this.setName = function (name) {
        this.name = name;
    };

    this.accept = function (visitor) {
        visitor.visit(self);
    };

    this.getName = function () {
        return name;
    };


    this.getType = function () {
        return type;
    };

    this.getLog = function () {
        return log;
    };
};

//Start using visitor


var verifyFile = function () {
    this.visit = function (file) {
       alert("test");
    };
};




function test(){
  var file = new Entity();
    file.accept(verifyFile);

};

Answer 1

You are injecting a function that defines a function, but your code is looking for an object that contains a function - see below

var Entity = function(file, name) {
  var self = this;
  var name;
  var type;
  var log = {};

  this.setName = function(name) {
    this.name = name;
  };

  this.accept = function(visitor) {
    visitor.visit(self);
  };

  this.getName = function() {
    return name;
  };


  this.getType = function() {
    return type;
  };

  this.getLog = function() {
    return log;
  };
};

//Start using visitor


var verifyFile = {
  visit : function(file) {
    alert("test");
  }
};


function test() {
  var file = new Entity();
  file.accept(verifyFile);
};

test()