As a user one can:

• read a list of tasks.
• add a task using the mouse or keyboard.
• mark any task as completed, using the mouse or keyboard.
• delete any task, using the mouse or keyboard.
• edit any task, using the mouse or keyboard.
• view a specific subset of tasks: All tasks, only the active task, or only the completed tasks.

• Componentizing the App
• React Interactivity:
  • Events and State
  • Editing & Filtering tasks
    • Interactive filter options that filter the tasks in the UI
  • Conditional Rendering the UI
    • View Template
    • Editing Template

<button type="button" className="btn toggle-btn" aria-pressed="true">
  <span className="visually-hidden">Show </span>
  <span>all</span>
  <span className="visually-hidden"> tasks</span>
</button>

aria-pressed tells assistive technology (like screen readers) that the button can be in one of two states: pressed or unpressed. True booleans in JSX are enclosed in curly braces without string literals

With the .visually-hidden class, elements will be from sighted users and still available to screen reader users. They provide more information to screen reader users

Implementing keyboard accessibility in React by ensuring the app is usable by keyboard and not just by mouse

Improve the User's experience managing the browser's focus in between templates by using the useRef hook

When a user toggles a <Todo/> template from viewing to editing, the focus should be on the <input> used to rename it; when they toggle back from editing to viewing, the focus should move back to the "Edit" button.

The ref constants are created in Todo.js for the:

• Edit button in the view template
• edit field in the editing template

const editFieldFocusRef = useRef(null);
const editButtonFocusRef = useRef(null);

<div className="form-group">
  <label className="todo-label" htmlFor={id}>
    New name for {name}
  </label>
  <input
    ref={editFieldFocusRef} // attach the ref attribute to the respective element
    id={id}
    className="todo-text"
    type="text"
    value={newName}
    onChange={handleChange}
  />
</div>

<button
  ref={editButtonFocusRef} // attach the ref attribute to the respective element
  type="button"
  className="btn todo-cancel"
  onClick={() => setIsEditing(false)}
>

Another ref constant is created in App.js for the:

• Focus to shift to the list heading whenever a user deletes a task

const listHeadingFocusRef = useRef(null);

<h2 id="list-heading" ref={listHeadingFocusRef} tabIndex="-1">
  {headingText}
</h2>

The <h2> element can become focusable by add the tabindex="-1" attribute to it tabindex MDN web Docs

This -1 tabIndex value means the element is only focusable with JavaScript

That means the element will be skipped when the user tabs through the elements on the page using the tab key as it's not in the normal tab order

This is typically used for elements that should be focusable by scripts, but are not interactive components that users should be able to tab to directly.

• User stories
• Componentizing the App
• Handling Events
• Variables & Props
• Callback Props(Passing Functions as props from parent to child component)
• Hooks
• useState & useRef hooks
• Controlled Components

Installed the tiny nanoid library in order to generate unique string IDs

Developed courtesy of MDN Web docs React tutorial with a few tweaks