In this final article of this course, we will learn how to make a simple javascript application where we can add tasks, delete tasks and edit them too. Pure(Vanilla) JavaScript has been used and we will also make use of DOM manipulation a lot so one of the main prerequisites is HTML | DOM.
Project Structure:
index.html
styles.css
list.js
Project Preview:
Course Tracker Project
Example: In this example code, we have built the course tracker project using javascript.
HTML
<!DOCTYPE html><html><head> <title>Task Tracker</title> <link rel="stylesheet" href="styles.css" type="text/css" media="screen" charset="utf-8"> </head><body> <div class="container"> <p> <label for="new-task" class="middle">Add Task</label> <input id="new-task" type="text"> <button>Add Task</button> </p> <h3 class="middle">Todo</h3> <ul id="incomplete-tasks"> </ul> <h3 class="middle">Completed Tasks</h3> <ul id="completed-tasks"> </ul> </div> <script type="text/javascript" src="list.js"></script> </body></html> |
CSS
/* Basic Style */ body { background: #ecf0f1; color: #333; font-family: Lato, sans-serif; } .container { display: block; width: 500px; margin: 50px auto 0; } ul { margin: 0; padding: 0; } li * { float: left; } li, h3 { clear: both; list-style: none; } input, button { outline: none; } button { background: none; border: 0; color: #888; font-size: 15px; width: 100px; margin: 10px 0 0; font-family: Lato, sans-serif; cursor: pointer; } button:hover { color: #333; } /* Heading */ h3, label[for='new-task'] { color: #333; font-weight: 700; font-size: 15px; border-bottom: 2px solid #333; padding: 30px 0 10px; margin: 0; text-transform: uppercase; } input[type="text"] { margin: 0; font-size: 18px; line-height: 18px; height: 18px; padding: 10px; border: 1px solid #ddd; background: #fff; border-radius: 6px; font-family: Lato, sans-serif; color: #888; } input[type="text"]:focus { color: #333; } .middle { text-align: center; } /* New Task */ label[for='new-task'] { display: block; margin: 0 0 20px; } input#new-task { float: right; width: 318px; } p>button:hover { color: #0FC57C; } /* Task list */ li { overflow: hidden; padding: 20px 0; border-bottom: 1px solid #eee; } li>input[type="checkbox"] { margin: 0 10px; position: relative; top: 15px; } li>label { font-size: 18px; line-height: 40px; width: 237px; padding: 0 0 0 11px; } li>input[type="text"] { width: 226px; } li>.delete:hover { color: #CF2323; } /* Completed */ #completed-tasks label { text-decoration: line-through; color: #888; } /* Edit Task */ ul li input[type=text] { display: none; } ul li.editMode input[type=text] { display: block; } ul li.editMode label { display: none; } |
Javascript
// Add a new task. let taskInput = document.getElementById("new-task"); // first button let addButton = document.getElementsByTagName("button")[0]; // ul of #incomplete-tasks let incompleteTaskHolder = document.getElementById("incomplete-tasks"); // completed-tasks let completedTasksHolder = document.getElementById("completed-tasks"); /*---- Part 1 ----*/ // function to create a new task item let createNewTaskElement = function (taskString) { let listItem = document.createElement("li"); // input (checkbox) let checkBox = document.createElement("input"); // label let label = document.createElement("label"); // input (text) let editInput = document.createElement("input"); // button.edit let editButton = document.createElement("button"); // button.delete let deleteButton = document.createElement("button"); label.innerText = taskString; // Each element needs appending checkBox.type = "checkbox"; editInput.type = "text"; // innerText encodes special characters, HTML does not. editButton.innerText = "Edit"; editButton.className = "edit"; deleteButton.innerText = "Delete"; deleteButton.className = "delete"; // Append elements listItem.appendChild(checkBox); listItem.appendChild(label); listItem.appendChild(editInput); listItem.appendChild(editButton); listItem.appendChild(deleteButton); return listItem; } /*---- Part 2 ----*/ let addTask = function () { let listItem = createNewTaskElement(taskInput.value); if (taskInput.value === "") { return; } // Append listItem to incompleteTaskHolder incompleteTaskHolder.appendChild(listItem); bindTaskEvents(listItem, taskCompleted); taskInput.value = ""; } /*---- Part 3 ----*/ let editTask = function () { let listItem = this.parentNode; let editInput = listItem.querySelector('input[type=text]'); let label = listItem.querySelector("label"); let containsClass = listItem.classList.contains("editMode"); // If class of the parent is .editmode if (containsClass) { label.innerText = editInput.value; } else { editInput.value = label.innerText; } listItem.classList.toggle("editMode"); } /*---- Part 4 ----*/ let deleteTask = function () { let listItem = this.parentNode; let ul = listItem.parentNode; // Remove the parent list item from the ul. ul.removeChild(listItem); } /*---- Part 5 ----*/ let taskCompleted = function () { // Append the task list item to the #completed-tasks let listItem = this.parentNode; completedTasksHolder.appendChild(listItem); bindTaskEvents(listItem, taskIncomplete); } /*---- Part 6 ----*/ let taskIncomplete = function () { // Mark task as incomplete. // When the checkbox is unchecked // Append the task list item to the #incomplete-tasks. let listItem = this.parentNode; incompleteTaskHolder.appendChild(listItem); bindTaskEvents(listItem, taskCompleted); } /*---- Part 7 ----*/ let bindTaskEvents = function (taskListItem, checkBoxEventHandler) { // select taskListItem's children let checkBox = taskListItem.querySelector("input[type=checkbox]"); let editButton = taskListItem.querySelector("button.edit"); let deleteButton = taskListItem.querySelector("button.delete"); // bind editTask to edit button editButton.onclick = editTask; // bind deleteTask to delete button deleteButton.onclick = deleteTask; // bind checkBoxEventHandler to checkbox checkBox.onchange = checkBoxEventHandler; } /*---- Part 8 ----*/ // Set the click handler to the addTask function addButton.addEventListener("click", addTask); addButton.addEventListener("click", ajaxRequest); /*---- Part 9 ----*/ // Cycle over incompleteTaskHolder ul list items for (let i = 0; i < incompleteTaskHolder.children.length; i++) { // bind events to list item's children (taskCompleted) bindTaskEvents(incompleteTaskHolder.children[i], taskCompleted); } /*---- Part 10 ----*/ // Cycle over completedTasksHolder ul list items for (let i = 0; i < completedTasksHolder.children.length; i++) { // bind events to list item's children (taskIncomplete) bindTaskEvents(completedTasksHolder.children[i], taskIncomplete); } |
Output: Click here to see live code output
JavaScript Course Task Tracker Project
Explanation:
The above HTML code contains simple list tags and one text field which we will populate with text when we add, or delete tasks. Certain classes are assigned which we make use of while getting that particular element by DOM or by styling it inside the styles.css file. All the above content is inside a div with the class ‘container’ that has its own styling and attributes.
Explanation
Part 1: The way this function works is that it takes the ‘inputString’ i.e. the text that we pass inside the HTML text field as a task and then it creates several elements using DOM properties and appends their specific classes. After appending we insert all the elements inside the list as listItems.
Part 2: This addTask function is called when we click the button ‘addButton'(line 115) and then inside it we create a listItem with the value the user entered and then check the value, as it must not be an empty string then we simply add the above value inside the ‘inputTaskHolder’ and finally setting the value inside it as an empty string before calling the ‘bindFunction’.
Part 3: This code function is used to edit an existing task and we do so by keeping track of the parent node and then a simple if-else check whether the ‘editMode’ button is clicked or not if clicked then simply assign the value of the label innerText to value inside the editInput, if not then vice versa. Then after editing, we toggle the value of the ‘editMode’ as we have edited.
Part 4: In this part, we delete a task, and the way we do it is by making use of the parent node of the current node and then storing the parent of the parent node, and then simply deleting the child of this node.
Part 5: In this function, we mark the task as complete by simply appending the child of the parent node inside completeTaskHolder element and then calling the bindFunction.
Part 6:In this function, we mark the task as incomplete by simply appending the child of the parent node inside inCompleteTaskHolder element and then calling the bindFunction.
Part 7: In this part, we call the BindFunction where we respond to several user interaction activities and make several buttons work.
Part 8: In this final section, we iterate over several parts binding children with the help of for loop inside the incomplete and complete TaskHolder element.
