I can not update the value of a String when I click on a particular button

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I'm doing a project for a calculator and I can not update the screen when someone presses the number 7, for example. Here is the code:

HTML: 

<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
 <body>
   <div class="py-0 text-center w-25"><div class="container">
       <form>
  <div class="row">
    <div class="col-md-12">
      <input type="text" class="form-control" placeholder="">
    </div>
  </div>
</form>
   </div></div>
    <div class="py-0 text-center w-25"><div class="container">
      <div class="row">
    <div class="col-md-3 btn btn-danger">AC</div>
    <div class="col-md-3 btn btn-danger">c</div>
    <div class="col-md-3 btn btn-primary">/</div>
    <div class="col-md-3 btn btn-primary ">x</div>
  </div></div></div><div class="py-0 text-center w-25"><div class="container"><div class="row">
    <div class="col-md-3 btn btn-primary" onclick="handlers.addTecla('7')">7</div>
    <div class="col-md-3 btn btn-primary">8</div>
    <div class="col-md-3 btn btn-primary">9</div>
    <div class="col-md-3 btn btn-primary">-</div>
  </div></div></div><div class="py-0 text-center w-25"><div class="container"><div class="row">
    <div class="col-md-3 btn btn-primary">4</div>
    <div class="col-md-3 btn btn-primary">5</div>
    <div class="col-md-3 btn btn-primary">6</div>
    <div class="col-md-3 btn btn-primary">+</div>
  </div></div></div><div class="py-0 text-center w-25"><div class="container"><div class="row">
    <div class="col-md-3 w-25 btn btn-primary">1</div>
    <div class="col-md-3 btn btn-primary">2</div>
    <div class="col-md-3 btn btn-primary">3</div>
    <div class="col-md-3 btn btn-primary">=</div>
  </div></div></div>
  <div class="py-0 text-center w-25"><div class="container"><div class="row">
    <div class="col-md-3 btn btn-primary">%</div>
    <div class="col-md-3 btn btn-primary">0</div>
    <div class="col-md-3 btn btn-primary">.</div>
    <div class="col-md-3 btn btn-primary">LN</div>
  </div></div></div> 
  <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js"integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.11.0/umd/popper.min.js"integrity="sha384-b/U6ypiBEHpOf/4+1nzFpr53nxSS+GLCkfwBdFNTxtclqqenISfwAzpKaMNFNmj4" crossorigin="anonymous"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/js/bootstrap.min.js"integrity="sha384-h0AbiXch4ZDo7tp9hKZ4TsHbi047NrKGLO3SEJAg45jXxnGIfYzk4Si90RDIqNm1" crossorigin="anonymous"></script>
</body>
</html>

CSS: 

.col-md-3{
  max-width: 50px;
  margin: 1px;
}
.col-md-12{
  max-width: 206px;
  margin: 1px;
}

JavaScript: 

var model = {
    tela: [""],
    addTecla: function(tecla){
        this.tela.push(tecla);
    },

var handlers = {
    addTecla: function(tecla){
        model.addTecla(tecla);
        view.displayTela;
    }
}

var view = {
    displayTela: function(){
        var pTela = document.getElementById('tela');
    pTela.innerHTML = '';
        var tela = model.tela.join('');
        pTela.innerHTML = tela;
    }
}

Link in codepen: link

    
asked by anonymous 11.12.2017 / 20:47

1 answer

0

In your HTML, you have to give id "screen" to input : 

<input id="tela" type="text" class="form-control" placeholder="">

In your JavaScript, you have placed a comma in place of the closing keys between the model object and the handlers object. Also, you were doing view.displayTela instead of calling the function doing view.displayTela() . Fixing it looks like this: 

var model = {
    tela: [""],
    addTecla: function(tecla){
        this.tela.push(tecla);
    }
}

var handlers = {
    addTecla: function(tecla){
        model.addTecla(tecla);
        view.displayTela();
    }
}

Finally, its function displayTela was moving in innerHTML of input . It's best to use value in this case: 

var view = {
    displayTela: function(){
        var pTela = document.getElementById('tela');
        pTela.value = '';
        var tela = model.tela.join('');
        pTela.value = tela;
    }
}

There are several other things that can be improved there, but for now, it solves the problem. Good studies!

    
11.12.2017 / 21:16
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