Validator in javascript is not workign

Question

Hello,trying to do extra task connected" with validating value of data that are inputed into "input" element. I try to make border of the input red if user typed nothing and submitted. I keep getting

Uncaught TypeError: Cannot read property 'style' of null
    at HTMLFormElement.form.addEventListener (app.js:42)

<!DOCTYPE html>
<html>
<head>
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>RSVP App</title>
  <link href="https://fonts.googleapis.com/css?family=Courgette" rel="stylesheet">
  <link href="https://fonts.googleapis.com/css?family=Lato:400,700" rel="stylesheet">
  <link href="css/style.css" rel="stylesheet">

</head>
<body>
  <div class="wrapper">
    <header>
      <h1>RSVP</h1>
      <p>A Treehouse App</p>
      <form id="registrar">
        <input type="text" name="name" placeholder="Invite Someone">
        <button type="submit" name="submit" value="submit">Submit</button>
      </form>
    </header>

    <div class="main">  
      <h2>Invitees</h2>
      <ul id="invitedList"></ul>    
    </div>
  </div>
  <script src="app.js"></script>
</body>
</html>

const form = document.getElementById('registrar');
const input = form.querySelector('input');
const ul = document.getElementById('invitedList');

function createli(text){
  const li = document.createElement('li');

  const span = document.createElement('span');
  span.textContent = text;
  li.appendChild(span);

  const label = document.createElement('label');
  label.textContent = 'Confirmed';
  li.appendChild(label);

  const checkbox = document.createElement('input');
  checkbox.type = 'checkbox';
  label.appendChild(checkbox);


  const editbutton = document.createElement('button');
  editbutton.textContent = 'Remove';

  const removebutton = document.createElement('button');
  removebutton.textContent = 'Edit';

  li.appendChild(editbutton); 
  li.appendChild(removebutton); 
  return li;
}

form.addEventListener('submit', (e) =>{
  e.preventDefault();
  const text = input.value;
  //validator
  if(text){
    input.value = '';
    const li = createli(text);
    ul.appendChild(li);
  }else{
    const form =document.getElementById(registrar);
    form.style.borderColor = 'red';
  }



});

ul.addEventListener('change', (e) => {
  const checkbox = e.target;
  const checked = checkbox.checked;
  const ListItem = checkbox.parentNode.parentNode;
  if(checked){
      ListItem.className = 'responded';
  }
  else{
      ListItem.className = '';
  }
});



ul.addEventListener('click', (e) => {
  if(e.target.tagName === 'BUTTON'){

      const button = e.target;
      const li = e.target.parentNode;
      const ul = li.parentNode;
      const buttontext = button.textContent;
      console.log(buttontext);
      const nameActions = {
        Remove: () => {
          ul.removeChild(li);
        },
        Edit: () => {
          const span = li.firstElementChild;
          const input = document.createElement('input');
          input.type = 'text';
          input.value = span.textContent;
          li.insertBefore(input, span);
          li.removeChild(span);
          button.textContent = 'Save';
        },
        Save: () => {
           const input = li.firstElementChild;
        const span = document.createElement('span');
        span.textContent = input.value;
        li.insertBefore(span,input);
        li.removeChild(input);
        button.textContent = 'Edit';
        }
      };
      nameActions[buttontext]();


  }

});

/* ================================= 
  Element Styles
==================================== */
red{
  border: solid 4px #e60000;
}
* {
  box-sizing: border-box;
}
body {
  font-family: 'Lato', sans-serif;
  color: #4c4c4c;
  background: #f8fdf3;
}
h1,
p,
form button {
  color: white;  
}
h1 {
  font-family: 'Courgette', cursive;
  text-shadow: 0 1px 0 rgba(0,0,0, .4);
  line-height: .65;
  margin-top: .5em;
  margin-bottom: 0;
}
h2 {
  margin-top: 0;
}
p {
  font-size: 1.1em;
  text-shadow: 0 1px 0 rgba(0,0,0, .25);
}
form {
  width: 60%;
  background: white;
  display: inline-block;
  overflow: hidden;
  display: -webkit-flex;
  display: flex;
  border-radius: .2em;
  border: solid 4px white;
  box-shadow: 0 1px 14px rgba(0,0,0, .12);
}
form button {
  padding: 0 1em;
  font-size: 1em;
  background: #7bcbc4;
  border-radius: .2em;
}
ul {
  list-style: none;
  padding: 0;
  margin: 2em 0 1em;
}
ul li {
  padding: 1em;
  background: #fff;
  border-radius: .2em;
  border: solid 1px rgba(88, 183, 205, .2);
  border-bottom: solid 2px rgba(88, 183, 205, .2);
  position: relative;
}
button {
  cursor: pointer;
}
input, 
button {
  border: none;
  outline: none;
}
header {
  text-align: center;
  background: linear-gradient(90deg, #d4eece, #55b3d0, #1e7eb7),
              url('../images/header-bg.jpg') no-repeat;
              background-blend-mode: multiply;    
              background-size: cover;   
}
header input {
  padding: 12px;
  font-size: 1.15em;
  width: 100%;
}
li span, 
li input[type=text] {
  color: #707070;
  font-size: 1.3em;
  margin-bottom: .3em;
}
li input[type=text] {
  padding: .2em;
  width: 95%;
  border: 1px dotted rgba(0,0,0, .2);
}
li label {
  font-size: .9em;
  display: block;
  color: rgba(112, 112, 112, .55);
}
li span, 
li input[type=text]:first-child {
  display: block;
}
li button {
  font-size: .78em;
  margin-top: 1.65em;
  margin-right: .4em;
  border-radius: .3em;
  padding: .4em .6em;
  color: white;
  background: #58b7cd;
}
li button:last-child {
  background: rgba(88, 183, 205, .5);
}
.wrapper {
  width: 100%;
  max-width: 900px;
  margin: 2.5em auto;
  border-radius: .35em;
  background: #fcfcfc;
  overflow: hidden;
  box-shadow: 0 0 26px rgba(0,0,0, .13);
}
div > input:last-child {
  font-size: 1em;
  margin-left: 6px;
}
div > label {
  color: #767676;
}

/* responded */
.responded {
  transition: 0.4s;
  border-color: rgba(88, 183, 205, .9);
}
.responded label {
  transition: 0.4s;
  color: rgba(88, 183, 205, 1);
}

/* ================================= 
  Media Queries
==================================== */

@media (min-width: 0) and (max-width: 768px) {
  header {
    padding: 1.25em;
  }
  h1 {
    font-size: 3.6em;
    margin: .3em 0 0;
  }
  ul li {
    margin-bottom: 1em;
  }
  form {
    width: 95%;
    -webkit-flex-direction: column;
    flex-direction: column;
    margin: auto;
    margin-top: 2.5em;
  }
  form button {
    padding: 12px 0;
    margin-top: .5em;
  }
  form input {
    font-size: 1em;
    text-align: center;
  }
  .wrapper {
    margin: 0;
  }
  .main {
    padding: 2em 1em .75em;
  }
}

@media (min-width: 769px) {
  header {
    height: 280px;
    padding: 2.5em 1em 1em;  
    background-position: 0 -95px; 
  }
  .main > div {
    float: right;
    display: inline-block;
    margin-top: 12px;
    margin-right: 1.25%;
  }
  div > label {
    margin-top: 12px;
  }
  h1 {
    font-size: 5.8em;
  }
  h2 {
    float: left;
    font-size: 1.9em;
    margin-left: 1.25%;
  }
  form {
    margin: 4.15em auto 0;
    z-index: 3000;
    position: relative;
  }
  .wrapper {
    width: 90%;
  }
  .main {
    padding: 3.8em 1.5em .75em;
    position: relative;
    z-index: 10;
  }
  ul {
    display: -webkit-flex;
    display: flex;
    clear: both;

    -webkit-justify-content: space-between;
    justify-content: space-between;
    -webkit-flex-wrap: wrap;    
    flex-wrap: wrap;
    padding-top: 1.25em;
  }
  ul li {
    -webkit-flex-grow: 1;
    flex-grow: 1;
    -webkit-flex-basis: 47.5%;
    flex-basis: 47.5%;
    margin: 0 1.25% 1em;
  }
}
@media (min-width: 880px) { 
  ul li {
    -webkit-flex-basis: 20%;
    flex-basis: 20%;
  }
}

do somebody know what's going on here? thx for an answer.

Answer 1 · 2017-04-28T16:26:16Z

April 28, 2017 4:26pm

If I had any guess, you are trying to target a class/id, yet your CSS selector targets red instead of .red/#red?

Not too sure as I'm still learning JavaScript and how to manipulate the DOM; however, it looks to me as though you forgot some syntax. I hope it helps!

:)

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Tomasz Cysewski

Tomasz Cysewski

Validator in javascript is not workign

1 Answer

Cory Harkins

Cory Harkins