Building a Todo App: Mastering JavaScript and DOM Manipulation

A Step-by-Step Guide to Creating an Interactive Todo List Application

Introduction: This is a list of tasks for a beginner to think about how to build the todo application. A link to detailed post with code is at the bottom. Make sure to look into it if only necessary.

Section 1: Setting Up the Project:Get ready to start coding by setting up the project environment:

  1. Create an empty directory for your project.
  2. Inside the directory, create an HTML file named "index.html."
  3. Add the basic HTML structure with <head> and <body> sections.
  4. Include a CSS file named "styles.css" within the <head> section for styling.
  5. Link your CSS file to the HTML using the <link> tag.
  6. Create a JavaScript file named "app.js" and link it at the end of the <body> section.
  7. Open the HTML file in a browser to ensure everything is set up correctly.

Section 2: Creating the User Interface:Build the user interface elements for the todo app:

  1. Inside the <body> section, create a <div> element with the class "container" to hold the app.
  2. Inside the container, add an <input> element with the ID "taskInput" for entering tasks.
  3. Create a <button> element with the ID "addTaskBtn" labeled "Add Task."
  4. Under the button, create an empty <ul> element with the ID "taskList" to display tasks.

Section 3: Adding Tasks Dynamically:Learn to add tasks to the list using DOM manipulation:

  1. In "app.js," select the input field using the document.getElementById method.
  2. Similarly, select the "Add Task" button using its ID.
  3. Use the addEventListener method to capture the click event on the button.
  4. Inside the event listener, retrieve the task input value using the value property.
  5. Create a new <li> element, set its inner text to the task, and append it to the <ul>.

Section 4: Checking off Tasks:Implement the functionality to mark tasks as completed:

  1. For each new <li> element, add a <input> checkbox before the task text.
  2. Assign a unique ID to each checkbox and label it as "taskCheckbox."
  3. Add an event listener to each checkbox to listen for the "change" event.
  4. Inside the event listener, toggle the class "completed" on the associated <li> element.
  5. Use CSS to style completed tasks differently, e.g., by changing the text color.

Section 5: Deleting Tasks:Allow users to remove tasks from the list:

  1. Beside each task, add a "Delete" button within a <button> element.
  2. Set a class name "deleteBtn" to the button for identification.
  3. Attach a click event listener to each delete button using addEventListener.
  4. Inside the event listener, use the removeChild method to delete the associated <li> element.

Section 6: Local Storage Integration:Ensure task persistence even after page refresh:

  1. Inside the event listener for adding tasks, after appending the <li>, save tasks to localStorage.
  2. Use the localStorage.setItem method to save tasks as a JSON string.
  3. On page load, retrieve tasks from localStorage using the localStorage.getItem method.
  4. Parse the JSON string back into an array of tasks and display them on the page.

Section 7: Styling and Final Touches:Add a touch of style to the app:

  1. Open "styles.css" and add basic styles to format the container, input, and button.
  2. Style the tasks with proper margins, padding, and alignment.
  3. Apply CSS transitions to create smooth animations for task completion and deletion.

Section 8: Conclusion and Next Steps:Celebrate your achievement and consider what's next:

  • Recap the journey and completed todo app.
  • Explore more JavaScript and web development concepts.
  • Look into frameworks like React or Vue for advanced projects.

Final Thoughts:Building a todo app is a fantastic way to dive into JavaScript and DOM manipulation. As you continue learning, you'll discover countless opportunities to create impressive web applications. Keep coding, exploring, and building!

Complete coding guide of todo app here