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javascriptknockout.jsdata-bindingprototype-programming

knockout.js issues: "h.apply is not a function. (In 'h.apply(e,r)', 'h.apply' is undefined)"


So I am trying to call a method on my viewModel prototype through data binding. I data-bind two different elements to the same method, both via "click". When I click the first button (New Game button), it displays what I want it to display. When I click the <td> associated with the data-bind, it throws the error "Type Error: h.apply is not a function. (In 'h.apply(e,r)', 'h.apply' is undefined). What am I doing wrong here?

The method I'm talking about is the Messages method on the viewModel prototype.

JAVASCRIPT

var message = (function(){
  function Message(){
   this.main = ko.observable(true);
   this.welcome = "Welcome to Tic-Tac-Toe! This is a 2 player game. Click New Game to play!"
   this.turn = ", its your turn."
   this.win = ", you won!"
   this.draw = "It's a draw..."
  }
  return Message;
})()

var players = (function(){
  function Players(){
    this.player1 = ko.observable(true);
    this.player2 = ko.observable(false);
  }
  return Players;
})()

var aBox = (function(){
  function ABox(){
    this.symbol = ko.observable(" ")
  }

  return ABox;
})()

var viewModel = (function(){
  function ViewModel(){
    this.GameMessage = new message();
    this.thePlayers = new players();
    this.r1c1 = new aBox();
    this.r1c2 = new aBox();
    this.r1c3 = new aBox();
    this.r2c1 = new aBox();
    this.r2c2 = new aBox();
    this.r2c3 = new aBox();
    this.r3c1 = new aBox();
    this.r3c2 = new aBox();
    this.r3c3 = new aBox();

  }

/**************************************** 
 ************* Messages *****************
 ****************************************/ 

  ViewModel.prototype.StartMessage = function(){

     this.GameMessage.main(false)
  }

  ViewModel.prototype.Messages = function(){

    if(this.GameMessage.main()){
      return this.GameMessage.welcome;
    }
    else if(this.thePlayers.player1()){
      this.thePlayers.player1(false);
      this.thePlayers.player2(true);
      return "Player 1"+this.GameMessage.turn;

    }
    else if(this.thePlayers.player2())
      this.thePlayers.player1(true);
      this.thePlayers.player2(false);
      return "Player 2"+this.GameMessage.turn;
  }






/**************************************** 
 ************* GamePlay *****************
 ****************************************/ 

/**************************************** 
 ************* If needed ****************
 ****************************************/ 






  return ViewModel;
})()

ko.applyBindings(new viewModel())

HTML(Jade Preprocessor)

p#title.col-xs-12.bg-primary.text-center
  | Tic - Tac - Toe!
div.col-xs-3.bg-info
  div.bg-primary.controls
    span
      button.btn.btn-default(data-bind="click:StartMessage.bind($root)")
        | New Game
      p#message.lead(data-bind="text:Messages.bind($root)()")
table.bg-success(style="table-layout:fixed;")
  tr#row1
    td(data-bind="click:Messages.bind($root)()")
    td &nbsp
    td &nbsp
  tr#row2
    td &nbsp 
    td &nbsp
    td &nbsp
  tr#row3
    td &nbsp 
    td &nbsp
    td &nbsp

Solution

  • The click binding requires a function to call. It appears you are invoking that function instead, binding to the result of calling the function. Remove the function call.

    Change this:

    td(data-bind="click:Messages.bind($root)()")
    

    to this:

    td(data-bind="click:Messages.bind($root)")