Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript Interactive Web Pages with JavaScript Traversing and Manipulating the DOM with JavaScript Perform: Traversing Elements with querySelector

Posted by Jamison Imhoff
Jamison Imhoff
12,460 Points

Syntax Error Issue with Javascript

I am trying to look at some console logs, but when I do the ctrl+shift+j shortcut on chrome to open the javascript console, it says "SyntaxError: Unexpected end of input".

The weird thing is IT IS ON A COMMENT ON THE 1ST LINE. I do not get how the //comment is being seen as a syntax error, and i cannot look at my console logs because the console stops at the first error.

help... please...

Code is unfinished, but here it is so far:

//Problem: User interaction doesn't provide desired results
//Solution: Add interactivity so the user can manage daily tasks

var taskInput = document.getElementById("new-task"); //new-task
var addButton = document.getElementsByTagName("button")[0]; //first button
var incompleteTasksHolder = document.getElementById("incomplete-tasks"); //incomplete-tasks
var completedTasksHolder = document.getElementById("completed-tasks"); //completed-tasks

//Add a new task
var addTask = function() {
  console.log("Add task...");
  //When the button is pressed
  //Create a new list item with the text from #new-task:
    //input checkbox
    //label
    //input (text)
    //button.edit
    //button.delete
    //Each elements, needs modified and appended
}

//Edit an existing task
var editTask = function() {
  console.log("Edit task...");
  //When the Edit button is pressed
    //if the class of the parent is .editMode
      //switch from .editMode
      //label text become the input's value
    //else
      //switch to .editMode
      //input value becomes the label's text

    //Toggle .editMode
}

//Delete an existing task
var deleteTask = function() {
  console.log("Delete task...");
  //When the Delete button is pressed
    //Remove the parent list item from the ul
}

//Mark a task as complete
var taskCompleted = function() {
  console.log("Task complete...");
  //When the Checkbox is checked
    //Append the task list item to the #completed-tasks
}

//Mark a task as incomplete
var taskIncomplete = function() {
  console.log("Task incomplete...");
  //When the checkbox is unchecked
    //Append the task list item to the #incompleted-tasks
}

var bindTaskEvents = function(taskListItem, checkBoxEventHandler) {
  console.log("Bind list item events");
  //select it's children
  var checkBox = taskListItem.querySelector("input[type=checkbox]");
  var editButton = taskListItem.querySelector("button.edit");
  var deleteButton = taskListItem.querySelector("button.delete");
    //bind editTask to edit button
    editButton.onclick = editTask;

    //bind deleteTask to delete button
    deleteButton.onclick = deleteTask;  

    //bind taskCompleted to checkbox
    checkBox.onchange = checkBoxEventHandler;
}

//Set the click handler to the addTask function
addButton.onclick = addTask; 

//cycle over incompleteTasksHolder ul list items
for(var i = 0; i < incompleteTasksHolder.children.length; i++) {
  //bind events to list item's children (taskCompleted)
  bindTaskEvents(incompleteTasksHolder.children[i], taskCompleted);
}

//cycle over completedTasksHolder ul list items
  for(var i = 0; i < incompleteTasksHolder.children.length; i++) {
  //bind events to list item's children (taskCompleted)
  bindTaskEvents(completedTasksHolder.children[i], taskIncomplete);

1 Answer

Hugo Paz
Hugo Paz
15,622 Points
Hugo Paz
Hugo Paz
15,622 Points

Hi Jamison,

You forgot to close the last for loop. Just add the closing curly braces and you should get rid of that error.

Jamison Imhoff
Jamison Imhoff
12,460 Points

Ok thanks. That helped, but now line 60 gets "Cannot read property 'querySelector' of undefined" >_>

Hugo Paz
Hugo Paz
15,622 Points
Hugo Paz
Hugo Paz
15,622 Points

Can you post the HTML as well?

Jamison Imhoff
Jamison Imhoff
12,460 Points

I can post it, but it was not altered in the video lesson: 

<!DOCTYPE html>
<html>
  <head>
    <title>Todo App</title>
    <link href='http://fonts.googleapis.com/css?family=Lato:300,400,700' rel='stylesheet' type='text/css'>
    <link rel="stylesheet" href="css/style.css" type="text/css" media="screen" charset="utf-8">    
  </head>
  <body>
    <div class="container">
      <p>
        <label for="new-task">Add Item</label><input id="new-task" type="text"><button>Add</button>
      </p>

      <h3>Todo</h3>
      <ul id="incomplete-tasks">
        <li><input type="checkbox"><label>Pay Bills</label><input type="text"><button class="edit">Edit</button><button class="delete">Delete</button></li>
        <li class="editMode"><input type="checkbox"><label>Go Shopping</label><input type="text" value="Go Shopping"><button class="edit">Edit</button><button class="delete">Delete</button></li>

      </ul>

      <h3>Completed</h3>
      <ul id="completed-tasks">
        <li><input type="checkbox" checked><label>See the Doctor</label><input type="text"><button class="edit">Edit</button><button class="delete">Delete</button></li>
      </ul>
    </div>

    <script type="text/javascript" src="js/app.js"></script>

  </body>
</html>
Hugo Paz
Hugo Paz
15,622 Points
Hugo Paz
Hugo Paz
15,622 Points

It seems the issue is in the last for loop,

You have:

//cycle over completedTasksHolder ul list items
  for(var i = 0; i < incompleteTasksHolder.children.length; i++) {
  //bind events to list item's children (taskCompleted)
  bindTaskEvents(completedTasksHolder.children[i], taskIncomplete);
}

but you are supposed to cycle through the completed tasks holder

//cycle over completedTasksHolder ul list items
  for(var i = 0; i < completedTasksHolder.children.length; i++) {
  //bind events to list item's children (taskCompleted)
  bindTaskEvents(completedTasksHolder.children[i], taskIncomplete);
}
Jamison Imhoff
Jamison Imhoff
12,460 Points

fixed the last loop, but line 60 still error

 var checkBox = taskListItem.querySelector("input[type=checkbox]");
Hugo Paz
Hugo Paz
15,622 Points
Hugo Paz
Hugo Paz
15,622 Points

With all the fixes i have no issues,

For testing purposes i kept all code in the same file

<!DOCTYPE html>
<html>
  <head>
    <title>Todo App</title>
    <link href='http://fonts.googleapis.com/css?family=Lato:300,400,700' rel='stylesheet' type='text/css'>
    <link rel="stylesheet" href="css/style.css" type="text/css" media="screen" charset="utf-8">    
  </head>
  <body>
    <div class="container">
      <p>
        <label for="new-task">Add Item</label><input id="new-task" type="text"><button>Add</button>
      </p>

      <h3>Todo</h3>
      <ul id="incomplete-tasks">
        <li><input type="checkbox"><label>Pay Bills</label><input type="text"><button class="edit">Edit</button><button class="delete">Delete</button></li>
        <li class="editMode"><input type="checkbox"><label>Go Shopping</label><input type="text" value="Go Shopping"><button class="edit">Edit</button><button class="delete">Delete</button></li>

      </ul>

      <h3>Completed</h3>
      <ul id="completed-tasks">
        <li><input type="checkbox" checked><label>See the Doctor</label><input type="text"><button class="edit">Edit</button><button class="delete">Delete</button></li>
      </ul>
    </div>

    <script>
    //Problem: User interaction doesn't provide desired results
//Solution: Add interactivity so the user can manage daily tasks

var taskInput = document.getElementById("new-task"); //new-task
var addButton = document.getElementsByTagName("button")[0]; //first button
var incompleteTasksHolder = document.getElementById("incomplete-tasks"); //incomplete-tasks
var completedTasksHolder = document.getElementById("completed-tasks"); //completed-tasks

//Add a new task
var addTask = function() {
  console.log("Add task...");
  //When the button is pressed
  //Create a new list item with the text from #new-task:
    //input checkbox
    //label
    //input (text)
    //button.edit
    //button.delete
    //Each elements, needs modified and appended
}

//Edit an existing task
var editTask = function() {
  console.log("Edit task...");
  //When the Edit button is pressed
    //if the class of the parent is .editMode
      //switch from .editMode
      //label text become the input's value
    //else
      //switch to .editMode
      //input value becomes the label's text

    //Toggle .editMode
}

//Delete an existing task
var deleteTask = function() {
  console.log("Delete task...");
  //When the Delete button is pressed
    //Remove the parent list item from the ul
}

//Mark a task as complete
var taskCompleted = function() {
  console.log("Task complete...");
  //When the Checkbox is checked
    //Append the task list item to the #completed-tasks
}

//Mark a task as incomplete
var taskIncomplete = function() {
  console.log("Task incomplete...");
  //When the checkbox is unchecked
    //Append the task list item to the #incompleted-tasks
}

var bindTaskEvents = function(taskListItem, checkBoxEventHandler) {
  console.log("Bind list item events");
  //select it's children
  var checkBox = taskListItem.querySelector("input[type=checkbox]");
  var editButton = taskListItem.querySelector("button.edit");
  var deleteButton = taskListItem.querySelector("button.delete");
    //bind editTask to edit button
    editButton.onclick = editTask;

    //bind deleteTask to delete button
    deleteButton.onclick = deleteTask;  

    //bind taskCompleted to checkbox
    checkBox.onchange = checkBoxEventHandler;
}

//Set the click handler to the addTask function
addButton.onclick = addTask; 

//cycle over incompleteTasksHolder ul list items
for(var i = 0; i < incompleteTasksHolder.children.length; i++) {
  //bind events to list item's children (taskCompleted)
  bindTaskEvents(incompleteTasksHolder.children[i], taskCompleted);
}

//cycle over completedTasksHolder ul list items
  for(var i = 0; i < completedTasksHolder.children.length; i++) {
  //bind events to list item's children (taskCompleted)
  bindTaskEvents(completedTasksHolder.children[i], taskIncomplete);
}
  </script>

  </body>
</html>

Can you please test this?