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JavaScript AJAX Basics Programming AJAX Processing JSON Data

Tomasz Grodzki
Tomasz Grodzki
7,705 Points

The list doesn't showup, instead I get [object HTMLUListElement]

Hello there!

My code doesn't work. Why I do get this '[object HTMLUListElement]' instead of list of employees?

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>AJAX Office Status Widget</title>
  <link href='http://fonts.googleapis.com/css?family=Varela+Round' rel='stylesheet' type='text/css'>
  <link rel="stylesheet" href="css/main.css">

</head>
<body>
  <div class="grid-container centered">
    <div class="grid-100">
      <div class="contained">
        <div class="grid-100">
          <div class="heading">
            <h1>Corporate Intranet</h1>
          </div>
        </div>
        <section class="grid-70 main">
          <h2>Lorem Ipsum Headline</h2>
          <p>Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur?</p>
          <p>Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur?</p>
          <p>Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur?</p>
        </section>
        <aside class="grid-30 list">
          <h2>Employee Office Status</h2>
          <div id="employeeList">

          </div>
        </aside>
        <footer class="grid-100">
          <p>Copyright, The Intranet Corporation</p>
        </footer>
      </div>
    </div>
  </div>
<script src="js/widget.js"></script>
</body>
</html>
var xhr = new XMLHttpRequest();

xhr.onreadystatechange = function ()
{
  if ( xhr.readyState === 4 )
  {
    let employees = JSON.parse ( xhr.responseText );
    let employeesList = document.createElement ( 'ul' )
    employeesList.className += 'bulleted';



    for ( let i = 0; i < employees.length; i ++ )
    {
      let employee = document.createElement ( 'li' );
      employee.innerHTML = employees[i].name;

      if ( employees[i].inoffice === false )
        employee.className += 'out';
    else 
        employee.className += 'in';

      employeesList.appendChild ( employee );

    }
    document.querySelector( '#employeeList' ).innerHTML = employeesList;
    console.log ( employeesList );
  }
};

xhr.open( 'GET', 'data/employees.json' );
xhr.send( 'index.html' );
Tomasz Grodzki
Tomasz Grodzki
7,705 Points

Okay, now I see where was the mistake. I made HTML list and I used .innerHTML property. So I deleted this mistake. But after modifying this code I get new error:

Uncaught ReferenceError: Invalid left-hand side in assignment at XMLHttpRequest.xhr.onreadystatechange

How can I solve this problem? Why this code worked when I made normal string and converted it by innerHTML properties but I can't add an existing html object to index.html like this:

    document.querySelector( '#employeeList' ) = employeesList;

Full modified JS code:

var xhr = new XMLHttpRequest();

xhr.onreadystatechange = function ()
{
  if ( xhr.readyState === 4 )
  {
    let employees = JSON.parse ( xhr.responseText );
    let employeesList = document.createElement ( 'ul' )
    employeesList.className += 'bulleted';



    for ( let i = 0; i < employees.length; i ++ )
    {
      let employee = document.createElement ( 'li' );
      employee.innerHTML = employees[i].name;

      if ( employees[i].inoffice === false )
        employee.className += 'out';
    else 
        employee.className += 'in';

      employeesList.appendChild ( employee );

    }
    document.querySelector( '#employeeList' ).innerHTML = employeesList;
    console.log ( employeesList );
  }
};

xhr.open( 'GET', 'data/employees.json' );
xhr.send( 'index.html' );

1 Answer

Try to append employeesList to your DOM