ContextQMD
Back to Freecodecamp

Step 29

curriculum/challenges/english/blocks/workshop-music-player/675057ce9acd418619127da4.md

latest17.7 KB
Original Source

--description--

Now, create a function named getPreviousSong. Make it return the song that can be found at getCurrentSongIndex() minus one in userData.songs, or undefined if the current song is the first one in the playlist.

--hints--

You should have a function named getPreviousSong.

js
assert.isFunction(getPreviousSong);

Your getPreviousSong function should call getCurrentSongIndex.

js
let flag;
const temp = getCurrentSongIndex;
getCurrentSongIndex = () => {flag = true};
try {
  getPreviousSong();
  assert.isTrue(flag);
} finally {
  getCurrentSongIndex = temp;
}

Your getPreviousSong function should return the song before the current song.

js
userData.currentSong = allSongs[4]
assert.equal(getPreviousSong(), allSongs[3]);

userData.currentSong = allSongs[3]
assert.equal(getPreviousSong(), allSongs[2]);

Your getPreviousSong function should return undefined when the current song is the first one in the playlist.

js
userData.currentSong = allSongs[0]
assert.isUndefined(getPreviousSong());

--seed--

--seed-contents--

html
<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <link href="https://fonts.googleapis.com/css2?family=Roboto+Mono&display=swap" rel="stylesheet" />
  <link href="https://fonts.googleapis.com/css2?family=Lato&family=Roboto+Mono&display=swap" rel="stylesheet" />
  <link rel="stylesheet" href="styles.css" />
  <title>
    Build a Music Player App
  </title>
</head>

<body>
  <div class="container">
    <div class="player">
      <div class="player-bar">
        <div class="parallel-lines">
          <div></div>
          <div></div>
        </div>
        <h1 class="fcc-title">freeCodeCamp</h1>
        <div class="parallel-lines">
          <div></div>
          <div></div>
        </div>
      </div>
      <div class="player-content">
        <div id="player-album-art">
          
        </div>
        <div class="player-display">
          <div class="player-display-song-artist">
            <p id="player-song-title"></p>
            <p id="player-song-artist"></p>
          </div>
          <div class="player-buttons">
            <button id="previous" class="previous" aria-label="Previous">
              <svg width="24" height="19" viewBox="0 0 24 19" fill="none" xmlns="http://www.w3.org/2000/svg">
                <path d="M23.2248 0L7.03964 9.5L23.2248 19L23.2248 0Z" />
                <rect width="4.63633" height="18.5453" transform="matrix(-1 0 0 1 4.63633 0)" />
              </svg>
            </button>
            <button id="play" class="play" aria-label="Play">
              <svg width="17" height="19" viewBox="0 0 17 19" fill="none" xmlns="http://www.w3.org/2000/svg">
                <path d="M0 0L16.1852 9.5L1.88952e-07 19L0 0Z" />
              </svg>
            </button>
            <button id="pause" class="pause" aria-label="Pause">
              <svg width="17" height="19" viewBox="0 0 17 19" fill="none" xmlns="http://www.w3.org/2000/svg">
                <path d="M0 6.54013e-07H4.75V19H0V6.54013e-07Z" />
                <path d="M11.4 0H16.15V19H11.4V0Z" />
              </svg>
            </button>
            <button id="next" class="next" aria-label="Next">
              <svg width="24" height="19" viewBox="0 0 24 19" fill="none" xmlns="http://www.w3.org/2000/svg">
                <path d="M0 0L16.1852 9.5L1.88952e-07 19L0 0Z" />
                <rect x="18.5885" width="4.63633" height="18.5453" />
              </svg>
            </button>
          </div>
        </div>
      </div>
    </div>
    <div class="playlist">
      <div class="playlist-bar">
        <div class="parallel-lines">
          <div></div>
          <div></div>
        </div>
        <h2 class="playlist-title" id="playlist">Playlist</h2>
        <div class="parallel-lines">
          <div></div>
          <div></div>
        </div>
      </div>
      <ul id="playlist-songs">
        <li id="song-0" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">Scratching The Surface</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">4:25</span>
          </button>
        </li>

        <li id="song-1" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">Can't Stay Down</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">4:15</span>
          </button>
        </li>

        <li id="song-2" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">Still Learning</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">3:51</span>
          </button>
        </li>

        <li id="song-3" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">Cruising for a Musing</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">3:34</span>
          </button>
        </li>

        <li id="song-4" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">Never Not Favored</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">3:35</span>
          </button>
        </li>

        <li id="song-5" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">From the Ground Up</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">3:12</span>
          </button>
        </li>

        <li id="song-6" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">Walking on Air</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">3:25</span>
          </button>
        </li>

        <li id="song-7" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">Can't Stop Me. Can't Even Slow Me Down.</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">3:52</span>
          </button>
        </li>

        <li id="song-8" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">The Surest Way Out is Through</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">3:10</span>
          </button>
        </li>

        <li id="song-9" class="playlist-song">
          <button class="playlist-song-info" >
            <span class="playlist-song-title">Chasing That Feeling</span>
            <span class="playlist-song-artist">Quincy Larson</span>
            <span class="playlist-song-duration">2:43</span>
          </button>
        </li>
      </ul>
    </div>
  </div>
  <script src="script.js"></script>
</body>

</html>
css
:root {
    /* colors */
    --primary-color: #dfdfe2;
    --secondary-color: #ffffff;
    --app-background-color: #4d4d62;
    --background-color: #1b1b32;
    --foreground-color: #3b3b4f;
    --highlight-color: #f1be32;

    /* font sizes */
    --root-font-size: 16px;
    font-size: var(--root-font-size);

    /* font-families */
    --font-headline: "Roboto Mono", monospace;
    --font-family: "Lato", sans-serif;
  }

  *,
  *::after,
  *::before {
    box-sizing: border-box;
  }

  body {
    background-color: var(--app-background-color);
    color: var(--primary-color);
    font-family: var(--font-family);
  }

  h1 {
    font-size: 1.125rem;
    line-height: 1.6;
  }

  h2 {
    font-size: var(--root-font-size);
  }

  ul {
    margin: 0;
  }

  .container {
    margin-top: 10px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    row-gap: 5px;
  }

  .player,
  .playlist {
    width: 450px;
    background-color: var(--background-color);
    border: 3px solid var(--foreground-color);
  }

  .player {
    height: 260px;
    padding: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    row-gap: 10px;
  }

  .player-bar,
  .playlist-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 5px;
    width: 100%;
    height: 30px;
    background-color: var(--foreground-color);
  }

  .parallel-lines {
    display: flex;
    flex-wrap: wrap;
    row-gap: 6px;
    padding: 0 5px;
  }

  .parallel-lines > div {
    height: 2px;
    width: 100%;
    min-width: 75px;
    background-color: var(--highlight-color);
  }

  .fcc-title,
  .playlist-title {
    color: var(--secondary-color);
    margin: 0 10px;
    font-family: var(--font-headline);
  }

  .player-content {
    display: flex;
    background-color: var(--foreground-color);
    width: 430px;
    height: 200px;
    column-gap: 13px;
    align-items: center;
    justify-content: center;
  }

  #player-album-art {
    background-color: var(--secondary-color);
    border: 6px solid var(--background-color);
  }

  #player-album-art img {
    width: 150px;
    display: block;
  }

  .player-display {
    display: flex;
    flex-direction: column;
    row-gap: 20px;
    padding: 14px;
    background-color: var(--background-color);
    height: 153px;
    width: 226px;
  }

  .player-display-song-artist {
    height: 80px;
  }

  .player-buttons svg {
    fill: var(--primary-color);
  }

  .playing > svg {
    fill: var(--highlight-color);
  }

  .player-buttons {
    display: flex;
    justify-content: space-around;
  }

  button {
    background: transparent;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    font-size: var(--root-font-size);
    outline-color: var(--highlight-color);
    text-align: center;
  }

  .playlist-song {
    outline-color: var(--highlight-color);
  }

  .playlist li:not(:last-child) {
    border-bottom: 1px solid var(--background-color);
  }

  button:focus,
  .playlist-song:focus {
    outline-style: dashed;
    outline-width: 2px;
  }

  /* Playlist */
  .playlist {
    height: auto;
    padding: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    row-gap: 10px;
  }

  #playlist-songs {
    width: 430px;
    height: 100%;
    background-color: var(--foreground-color);
    display: flex;
    flex-direction: column;
    row-gap: 8px;
    padding: 8px 9px;
    visibility: visible;
    justify-content: start;
    list-style: none;
  }

  .playlist-song {
    display: flex;
    height: 55px;
    justify-content: space-between;
    align-items: center;
    padding: 5px;
  }

  [aria-current="true"] {
    background-color: var(--background-color);
  }

  [aria-current="true"] p {
    color: var(--highlight-color);
  }

  .playlist-song-info {
    height: 100%;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-around;
    column-gap: 7px;
    padding: 5px 0;
    font-family: var(--font-family);
  }

  #player-song-title,
  #player-song-artist {
    margin: 0;
  }

  #player-song-artist {
    color: var(--highlight-color);
    font-size: 0.75rem;
  }

  #player-song-title {
    font-size: 1.125rem;
  }

  .playlist-song-title {
    font-size: 0.85rem;
    width: 241px;
    text-align: left;
  }

  .playlist-song-artist {
    font-size: 0.725rem;
    width: 80px;
  }

  .playlist-song-duration {
    font-size: 0.725rem;
    margin: auto;
    font-family: var(--font-headline);
    width: 30px;
  }

  .playlist-song-delete {
    padding: 0;
    width: 20px;
    height: 20px;
  }

  .playlist-song-delete,
  .playlist-song-delete {
    fill: var(--foreground-color);
  }

  .playlist-song-delete:hover circle,
  .playlist-song-delete:focus circle {
    fill: #ff0000;
  }

  @media (max-width: 700px) {
    .player,
    .playlist {
      width: 300px;
    }

    .player {
      height: 340px;
    }

    #playlist-songs {
      height: 280px;
      padding: 5px 6px;
      overflow-y: scroll;
      overflow-x: hidden;
      scrollbar-color: var(--background-color) var(--secondary-color);
      scrollbar-width: thin;
    }

    #playlist-songs::-webkit-scrollbar {
      width: 5px;
    }

    #playlist-songs::-webkit-scrollbar-track {
      background: var(--background-color);
    }

    #playlist-songs::-webkit-scrollbar-thumb {
      background: var(--secondary-color);
    }

    h1 {
      font-size: 0.813rem;
    }

    h2 {
      font-size: 0.75rem;
    }

    .player-bar,
    .playlist-bar,
    .player-content,
    #playlist-songs {
      width: 280px;
    }

    .playlist-song {
      justify-content: space-between;
    }

    .playlist-song-title {
      width: 140px;
    }

    .playlist-song-artist {
      width: 40px;
    }

    .playlist-song-duration > button {
      padding: 0;
    }

    .player-content {
      display: inline;
      position: relative;
      justify-items: center;
      height: 100%;
    }

    #player-album-art {
      z-index: -100;
      height: 280px;
      box-shadow: none;
      background: #000;
    }

    #player-album-art img {
      width: 100%;
      opacity: 0.6;
    }

    .player-display-song-artist {
      padding: 0 10px;
    }

    .player-display-song-artist > p {
      white-space: pre-wrap;
    }

    .player-display {
      position: absolute;
      width: 100%;
      z-index: 1000;
      background-color: transparent;
      top: 0;
      height: 280px;
      justify-content: space-between;
      text-align: center;
    }
  }
js
const playlistSongs = document.getElementById("playlist-songs");
const playButton = document.getElementById("play");
const pauseButton = document.getElementById("pause");
const nextButton = document.getElementById("next");
const previousButton = document.getElementById("previous");
const allSongs = [
  {
    id: 0,
    title: "Scratching The Surface",
    artist: "Quincy Larson",
    duration: "4:25",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/scratching-the-surface.mp3",
  },
  {
    id: 1,
    title: "Can't Stay Down",
    artist: "Quincy Larson",
    duration: "4:15",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/can't-stay-down.mp3",
  },
  {
    id: 2,
    title: "Still Learning",
    artist: "Quincy Larson",
    duration: "3:51",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/still-learning.mp3",
  },
  {
    id: 3,
    title: "Cruising for a Musing",
    artist: "Quincy Larson",
    duration: "3:34",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/cruising-for-a-musing.mp3",
  },
  {
    id: 4,
    title: "Never Not Favored",
    artist: "Quincy Larson",
    duration: "3:35",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/never-not-favored.mp3",
  },
  {
    id: 5,
    title: "From the Ground Up",
    artist: "Quincy Larson",
    duration: "3:12",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/from-the-ground-up.mp3",
  },
  {
    id: 6,
    title: "Walking on Air",
    artist: "Quincy Larson",
    duration: "3:25",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/walking-on-air.mp3",
  },
  {
    id: 7,
    title: "Can't Stop Me. Can't Even Slow Me Down.",
    artist: "Quincy Larson",
    duration: "3:52",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/cant-stop-me-cant-even-slow-me-down.mp3",
  },
  {
    id: 8,
    title: "The Surest Way Out is Through",
    artist: "Quincy Larson",
    duration: "3:10",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/the-surest-way-out-is-through.mp3",
  },
  {
    id: 9,
    title: "Chasing That Feeling",
    artist: "Quincy Larson",
    duration: "2:43",
    src: "https://cdn.freecodecamp.org/curriculum/js-music-player/chasing-that-feeling.mp3",
  },
];

const audio = new Audio();

const userData = {
  songs: allSongs,
  currentSong: null,
  songCurrentTime: 0,
}

const playSong = id => {
  const song = userData.songs.find((song) => song.id === id);
  audio.src = song.src;
  audio.title = song.title;
  if (userData.currentSong === null) {
    audio.currentTime = 0
  } else {
    audio.currentTime = userData.songCurrentTime;
  }
  userData.currentSong = song;
  playButton.classList.add("playing");
  audio.play()
}

const pauseSong = () => {
  userData.songCurrentTime = audio.currentTime;
  playButton.classList.remove("playing");
  audio.pause();
}

const getCurrentSongIndex = () => userData.songs.indexOf(userData.currentSong);

const getNextSong = () => userData.songs[getCurrentSongIndex() + 1];

--fcc-editable-region--

--fcc-editable-region--

const playNextSong = () => {
  if (userData.currentSong === null) {
    playSong(userData.songs[0].id);
    return
  }
  const nextSong = getNextSong();
  if (nextSong) {
    playSong(nextSong.id);
  } else {
    userData.currentSong = null;
    userData.songCurrentTime = 0;
    pauseSong();
  }
}

playButton.addEventListener("click", () => {
  if (userData.currentSong === null) {
    playSong(userData.songs[0].id);
  } else {
    playSong(userData.currentSong.id);
  }
});

const songs = document.querySelectorAll(".playlist-song");

songs.forEach((song) => {
  const id = song.getAttribute("id").slice(5);
  const songBtn = song.querySelector("button");
  songBtn.addEventListener("click", () => {
      playSong(Number(id));
  })
})

pauseButton.addEventListener("click", pauseSong);

nextButton.addEventListener("click", playNextSong);