プログラマーへの道 #39 の補足説明 - プログラマー VTuber 衣亥栖ティオのちょっとした話

こんにちは、プログラマー VTuberの衣亥栖ティオです。
今回は以下の動画の補足説明をします。動画内で実装したソースコードも載せています。

今回の動画で実装したソースコード
JavaScriptで時間を扱う

今回の動画で実装したソースコード

以下が今回実装したソースコードです。

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

<head>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <!-- Bootstrap CSS -->
  <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.0/dist/css/bootstrap.min.css" rel="stylesheet"
    integrity="sha384-KyZXEAg3QhqLMpG8r+8fhAXLRk2vvoC2f3B09zVXn8CA5QIVfZOJ3BCsw2P0p/We" crossorigin="anonymous">

  <title>メモ帳アプリ</title>
</head>

<body>
  <div>
    <h3>メモの登録</h3>
    <button id="id-add-button">メモを登録する</button>
  </div>
  <div>
    <h3>メモの一覧</h3>
    <button id="id-delete-button">削除する</button>
    <table class="table">
      <thead>
        <tr>
          <th scope="col"><input type="checkbox" id="id-delete-all-memos"></th>
          <th scope="col">タイトル</th>
          <th scope="col">作成日</th>
          <th scope="col">更新日</th>
          <th scope="col">編集</th>
        </tr>
      </thead>
      <tbody id="id-memo-list">
      </tbody>
    </table>


    <div class="modal fade" id="exampleModal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <h5 class="modal-title" id="exampleModalLabel">編集</h5>
            <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
          </div>
          <div class="modal-body">
            <div id="id-validation-error-in-edit-modal" class="alert alert-danger" style="display:none;" role="alert">
            </div>
            <div class="input-group mb-3">
              <span class="input-group-text" id="inputGroup-sizing-default">タイトル</span>
              <input type="text" id="id-modal-title" class="form-control" aria-label="Sizing example input"
                aria-describedby="inputGroup-sizing-default">
              <input type="hidden" id="id-memo-id">
            </div>
            <div class="form-floating">
              <textarea class="form-control" style="height: 150px;" placeholder="Leave a comment here"
                id="id-modal-body"></textarea>
              <label for="id-modal-body">本文</label>
            </div>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Close</button>
            <button type="button" id="id-update-button" class="btn btn-primary">更新</button>
          </div>
        </div>
      </div>
    </div>

    <div class="modal fade" id="id-add-modal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <h5 class="modal-title" id="id-add-modal-label">登録</h5>
            <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
          </div>
          <div class="modal-body">
            <div id="id-validation-error-in-add-modal" class="alert alert-danger" style="display:none;" role="alert">
            </div>
            <div class="input-group mb-3">
              <span class="input-group-text" id="inputGroup-sizing-default">タイトル</span>
              <input type="text" id="id-add-modal-title" class="form-control" aria-label="Sizing example input"
                aria-describedby="inputGroup-sizing-default">
            </div>
            <div class="form-floating">
              <textarea class="form-control" style="height: 150px;" placeholder="Leave a comment here"
                id="id-add-modal-body"></textarea>
              <label for="id-add-modal-body">本文</label>
            </div>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Close</button>
            <button type="button" id="id-add-modal-button" class="btn btn-primary">登録</button>
          </div>
        </div>
      </div>
    </div>

  </div>


  <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.0/dist/js/bootstrap.bundle.min.js"
    integrity="sha384-U1DAWAznBHeqEIlVSCgzq+c9gqGAJn5c/t99JyeKa9xxaYpSvHU5awsuZVVFIhvj"
    crossorigin="anonymous"></script>
</body>

<script>
  const myModal = new bootstrap.Modal(document.getElementById('exampleModal'))
  const addModal = new bootstrap.Modal(document.getElementById('id-add-modal'))

  const addButtonInModal = document.getElementById("id-add-modal-button")
  addButtonInModal.addEventListener("click", (event) => {
    const title = document.getElementById("id-add-modal-title").value
    const body = document.getElementById("id-add-modal-body").value

    const errorMessage = document.getElementById("id-validation-error-in-add-modal")
    errorMessage.innerHTML = ""
    if (title.length < 1 || title.length > 30) {
      errorMessage.innerHTML = "タイトルの文字数は1文字以上30文字以下にしてください。<br>"
    }

    if (body.length < 1 || body.length > 100) {
      errorMessage.innerHTML = errorMessage.innerHTML + "本文の文字数は1文字以上100文字以下にしてください。<br>"
    }

    const tmp = document.getElementById("id-memo-list")
    if (tmp.children.length > 0) {
      Array.from(tmp.children).forEach((tr) => {
        const t = document.getElementById("id-title-in-list-" + tr.id).innerText
        if (title == t) {
          errorMessage.innerHTML = errorMessage.innerHTML + "すでに登録済みのタイトルです。<br>"
        }
      })
    }

    if (errorMessage.innerHTML.length > 0) {
      errorMessage.style.display = ""
      return
    }

    const now = new Date()

    //あとでライブラリで実装する
    var min = now.getMinutes()
    if (min < 10) {
      min = "0" + min
    }

    const createdAt = now.getFullYear() + "-" + (now.getMonth() + 1) + "-" + now.getDate() + " " + now.getHours() + ":" + min + ":" + now.getSeconds()
    const updatedAt = "なし"
    const memoId = now.getTime()

    const tr = document.createElement("tr")
    tr.setAttribute("id", memoId)

    const editButtonId = "id-edit-button-" + memoId
    const idTitleInList = "id-title-in-list-" + memoId
    const updatedAtId = "id-updated-at-" + memoId

    tr.innerHTML = '<td><input class="class-checkbox" data-memo-id="' + memoId + '" type="checkbox"></td><td id="' + idTitleInList + '">' + title + '</td><td>' + createdAt + '</td><td id="' + updatedAtId + '">' + updatedAt + '</td><td><button type="button" data-memo-id="' + memoId + '" id="' + editButtonId + '" class="btn btn-primary">編集</button></td>'
    const memoList = document.getElementById("id-memo-list")
    memoList.appendChild(tr)

    const inputForBody = document.createElement("input")
    inputForBody.setAttribute("id", "id-body-in-list-" + memoId)
    inputForBody.setAttribute("type", "hidden")
    inputForBody.value = body
    tr.appendChild(inputForBody)

    const editButton = document.getElementById(editButtonId)
    editButton.addEventListener("click", (event) => {
      const errorMessage = document.getElementById("id-validation-error-in-edit-modal")
      errorMessage.style.display = "none"
      errorMessage.innerHTML = ""

      const memoId = event.currentTarget.dataset.memoId
      document.getElementById("id-memo-id").value = memoId

      const title = document.getElementById("id-title-in-list-" + memoId).innerText
      const titleElement = document.getElementById("id-modal-title")
      titleElement.value = title

      const body = document.getElementById("id-body-in-list-" + memoId).value
      const bodyElement = document.getElementById("id-modal-body")
      bodyElement.value = body

      document.getElementById("exampleModalLabel").innerText = "編集"
      myModal.show()
    })
    addModal.hide()
  })

  const addButton = document.getElementById("id-add-button")
  addButton.addEventListener("click", (event) => {
    document.getElementById("id-add-modal-title").value = ""
    document.getElementById("id-add-modal-body").value = ""
    addModal.show()

    const errorMessage = document.getElementById("id-validation-error-in-add-modal")
    errorMessage.style.display = "none"
    errorMessage.innerHTML = ""
  })

  const deleteButton = document.getElementById("id-delete-button")
  deleteButton.addEventListener("click", (event) => {
    const checkboxes = document.getElementsByClassName("class-checkbox")
    Array.from(checkboxes).forEach((checkbox) => {
      if (checkbox.checked == false) {
        return false
      }

      const memoId = checkbox.dataset.memoId
      document.getElementById(memoId).remove()
    })
  })

  const deleteAllMemos = document.getElementById("id-delete-all-memos")
  deleteAllMemos.addEventListener("change", (event) => {
    const checkboxes = document.getElementsByClassName("class-checkbox")
    if (checkboxes.length == 0) {
      return
    }

    Array.from(checkboxes).forEach((checkbox) => {
      if (deleteAllMemos.checked == true) {
        checkbox.checked = true
      } else {
        checkbox.checked = false
      }
    })
  })

  const updateButton = document.getElementById("id-update-button")
  updateButton.addEventListener("click", (event) => {
    const memoId = document.getElementById("id-memo-id").value

    const title = document.getElementById("id-modal-title").value
    const body = document.getElementById("id-modal-body").value

    const errorMessage = document.getElementById("id-validation-error-in-edit-modal")
    errorMessage.innerHTML = ""
    if (title.length < 1 || title.length > 30) {
      errorMessage.innerHTML = "タイトルの文字数は1文字以上30文字以下にしてください。<br>"
    }

    if (body.length < 1 || body.length > 100) {
      errorMessage.innerHTML = errorMessage.innerHTML + "本文の文字数は1文字以上100文字以下にしてください。<br>"
    }

    const tmp = document.getElementById("id-memo-list")
    if (tmp.children.length > 0) {
      Array.from(tmp.children).forEach((tr) => {
        if (tr.id == memoId) {
          return
        }

        const t = document.getElementById("id-title-in-list-" + tr.id).innerText
        if (title == t) {
          errorMessage.innerHTML = errorMessage.innerHTML + "すでに登録済みのタイトルです。<br>"
        }
      })
    }

    if (errorMessage.innerHTML.length > 0) {
      errorMessage.style.display = ""
      return
    }


    //メモリストのタイトル
    document.getElementById("id-title-in-list-" + memoId).value = title

    //本文
    document.getElementById("id-body-in-list-" + memoId).value = body

    const now = new Date()
    const updatedAt = now.getFullYear() + "-" + (now.getMonth() + 1) + "-" + now.getDate()
    document.getElementById("id-updated-at-" + memoId).innerText = updatedAt

    myModal.hide()
  })

</script>

</html>