README.md

Todo App - Frontend Mentor Challenge

Goals

• Add new todos to the list
• Mark todos as completed
• Delete todos from the list
• Clear all completed todos
• Filter by all/active/complete todos
• Toggle light and dark mode
• Bonus: Drag and drop to reorder items on the list

UI/UX Features

Toggle light and dark mode on or off. Add todos that are saved in local storage. Full CRUD operations. Todos can be checked with a visual strike through. View todos by all, active, or completed. Drag and drop to reorder todos!

Solutions & Problems Solved

• Delete current todo. Seems like magic!

  setTodos(prev => prev.filter(t => t.id != todo.id))

• Get current item when clicked.

  const currentClicked = todos.filter(t => t.id == todo.id)

• Updating object properties in an array. Copy the previous props with the spread operator, then update the isCompleted prop from the click event. This will update state and local storage and render the checkbox as checked on render or reload.

  const updatedTodos = todos.map(t => {
    if (t.id === currentClicked[0].id) {
      return {
        ...t,
        isCompleted: e.target.checked
      }
    } else {
      return t
    }
  })

• Filtering todos with .filter(), based on React docs, say to use useMemo for performance only. My solution seems to work fine so far. Create a new array from todos array and save it in a variable named filteredTodos, then return those todos matching conditions based on which button/tab is selected.

  let filteredTodos
  
  filteredTodos = todos.filter(t => {
    if (tab === "all") {
      return t
    } else if (tab === "active") {
      return !t.isCompleted
    } else if (tab === "completed") {
      return t.isCompleted
    }
  })

  Then render the filteredTodos.

  {
    filteredTodos.map(todo => <ListItem todo={todo} todos={todos} id={todo.id} key={todo.id} setTodos={setTodos} isLeft={isLeft} />)
  }

  Updating the checked property from the click event.

  <input className="display__li-input" type="checkbox" onChange={handleChange} checked={todo.isCompleted} />

• Drag and Drop Feature

  I wanted a solution that did not require a library. I found this YouTube video on very simple solution using index from the map() array method and React useRef.

  Youtube: [https://www.youtube.com/watch?v=CYKDtVZr_Jw]

  Github: [https://github.com/thebikashweb/react-drag-drop-without-library/blob/master/src/pages/ListSort.tsx]

References

• React Docs

Accessiblity

• aria-labels to announce which item is being checked and deleted.
• changed color gradient on checkboxes to meet WCAG AA Graphical and User Interface Components