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Start your free trialJennifer Hughes
11,421 PointsUncaught TypeError: Cannot read property 'querySelector' of undefined
This error seems to be a common one, but I cannot figure out what I've done wrong. It's been that kind of day! Thanks in advance for your help.
//Problem: User interaction doesn't provide desired results
//Solution: Add interactivty so the user can manage daily tasks
//Add a new task
var taskInput = document.getElementById("new-task"); //#new-task
var addButton = document.getElementsByTagName("button")[0]; //first button
var incompleteTasksHolder =document.getElementById("incomplete-tasks"); //unordered list #incomplete-tasks
var completedTasksHolder =document.getElementById("completed-tasks"); // #completed-tasks
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) when we edit the task
//button .edit
//button .delete
//Each element will need to be modified and appended
}
var editTask = function() {
console.log("edit task")
//Edit an existing 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
}
var deleteTask = function() {
console.log("delete task")
//Delete an existing task
//When the delete button is pressed
//Remove the parent list item from the unordered list
}
var taskCompleted = function() {
console.log("complete task")
//Mark a task as complete
//When the checkbox is checked
//Append the task list item to the #completed-tasks
}
var taskIncomplete = function() {
console.log("incomplete task")
//Mark a task as incomplete
//When the checkbox is unchecked
//append the task list item to the #incomplete-tasks
}
//WIRING
var bindTaskEvents = function(taskListItem, checkBoxEventHandler) {
console.log("Bind listitem events");
//select taskListItem'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 checkBoxEventHandler to the checkbox
checkbox.onchange = checkBoxEventHandler;
}
//Set the click handler to the addTask function
addButton.onclick = addTask;
//cycle over the incompleteTasksHolder ul list item
for(var i = 0; i < incompleteTasksHolder.children.length; i++) {
//bind events to list item's children(taskCompleted)
bindTaskEvents(incompleteTasksHolder.children[i], taskCompleted);
}
//cycle over the completeTasksHolder ul list item
for(var i = 0; i < incompleteTasksHolder.children.length; i++) {
//bind events to list item's children(taskCompleted)
bindTaskEvents(completedTasksHolder.children[i], taskIncomplete);
}
2 Answers
Marcus Parsons
15,719 PointsHey again Jennifer,
In the very bottom for loop, in the for loop itself, it should be iterating over the completedTasksHolder
not incompleteTasksHolder
.
//changed incompleteTasksHolder to completedTasksHolder
for(var i = 0; i < completedTasksHolder.children.length; i++) {
//bind events to list item's children(taskCompleted)
bindTaskEvents(completedTasksHolder.children[i], taskIncomplete);
}
Jennifer Hughes
11,421 PointsAhhh, thank you!
Marcus Parsons
15,719 PointsYou're welcome :)