JSFiddle - React, Tailwind, and code Playground

[ASSIGNMENT] Close Frontend Application Quiz

by Farzad YZ

HTML

<script src="https://unpkg.com/[email protected]/umd/react.development.js"></script>
<script src="https://unpkg.com/[email protected]/umd/react-dom.development.js"></script>
<div id="root"></div>

CSS

.List {
  margin: 16px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  grid-auto-rows: 60px;
  grid-gap: 16px;
}

.List__item {
  line-height: 60px;
  text-align: center;
  color: white;
  text-shadow: 1px 1px rgba(0, 0, 0, 0.5);
  box-shadow: 0px 1px 1px 0px rgba(0, 0, 0, 0.05);
}

.List__item--selected {
  border: 4px solid red;
}

.List__item__button {
  display: block;
  width: 100%;
  height: 100%;
  background-color: transparent;
  border: none;
  cursor: pointer;
  color: inherit;
}

/* Taken from https://clrs.cc/ */

.List__item--navy {
  background-color: #001f3f;
}

.List__item--blue {
  background-color: #0074d9;
}

.List__item--aqua {
  background-color: #7fdbff;
}

.List__item--teal {
  background-color: #39cccc;
}

.List__item--olive {
  background-color: #3d9970;
}

.List__item--green {
  background-color: #2ecc40;
}

.List__item--lime {
  background-color: #01ff70;
}

.List__item--yellow {
  background-color: #ffdc00;
}

.List__item--orange {
  background-color: #ff851b;
}

.List__item--red {
  background-color: #ff4136;
}

.List__item--maroon {
  background-color: #85144b;
}

.List__item--fuchsia {
  background-color: #f012be;
}

.List__item--purple {
  background-color: #b10dc9;
}

.List__item--black {
  background-color: #111111;
}

.List__item--gray {
  background-color: #aaaaaa;
}

.List__item--silver {
  background-color: #dddddd;
}

React

const { Fragment, useState, useReducer, memo, useCallbackl } = React;


// Implement a feature to allow item selection with the following requirements:
// 1. Clicking an item selects/unselects it.
// 2. Multiple items can be selected at a time.
// 3. Make sure to avoid unnecessary re-renders of each list item in the big list (performance).
// 4. Currently selected items should be visually highlighted.
// 5. Currently selected items' names should be shown at the top of the page.
//
// Feel free to change the component structure at will.

const List = ({ items }) => {
  const [selection, setSelection] = useState(new Set());
  return (
    <Fragment>
      <ul>
        {Array.from(selection).map((name) => (
          <li key={name}>{name}</li>
        ))}
      </ul>
      <ul className="List">
        {items.map((item) => (
          <ListItem
            key={item.name}
            onToggleSelect={() => {
              setSelection((curr) => {
                const newCurr = new Set(curr);
                if (newCurr.has(item.name)) {
                  newCurr.delete(item.name);
                  return newCurr;
                }
                return newCurr.add(item.name);
              });
            }}
            name={item.name}
            color={item.color}
            isSelected={selection.has(item.name)}
          />
        ))}
      </ul>
    </Fragment>
  );
};

const ListItem = memo(
  ({
    name,
    color,
    onToggleSelect,
    isSelected,
  }) => {
    return (
      <li
        key={name}
        className={`List__item List__item--${color} ${
          isSelected ? 'List__item--selected' : ''
        }`}
      >
        <button
          className="List__item__button"
          onClick={() => {
            onToggleSelect();
          }}
        >
          {name}
        </button>
      </li>
    );
  },
  (prev, next) =>
    prev.color === next.color &&
    prev.isSelected === next.isSelected &&
    prev.name === next.name
);

//...