圖書查詢

我們可以在顯示某本圖書的頁面，順便帶出這本圖書的借閱記錄，方便我們了解有哪些讀者在哪些時候借閱了這本書。

修改 library/book/views.py 用來處理檢視圖書的視圖類別 BookView，為其新增 get_context_data() 方法：

from django.contrib.auth.mixins import LoginRequiredMixin
from .models import *
from log.models import Log

class BookView(LoginRequiredMixin, DetailView): # 檢視圖書
    model = Book

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['log_list'] = Log.objects.filter(
            book=self.object, 
        ).order_by('-id').select_related('reader')
        return ctx

在 views 中取得所需資料後，接下來就可以修改頁面範本 library/templates/book/book_detail.html 插入第 28 - 58 行將借閱紀錄補上：

  <div class="col-sm-8">
    <div class="card">
      <div class="card-header">{{ book.title }}</div>
      <table class="table">
        <tr>
          <th>作者</th><td>{{ book.author }}</td>
        </tr>
        <tr>
          <th>出版社</th><td>{{ book.publisher }}</td>
        </tr>
      </table>
    </div>
    <div class="card">
      <div class="card-header">
        借閱紀錄
      </div>
      <ul class="list-group">
        {% for log in log_list %}
        <li class="list-group-item d-flex justify-content-between">
          <div>
            <span class="badge">
            {{ log.checkout|date:"Y/m/d H:i" }}
            <i class="fas fa-arrow-alt-circle-right"></i>
            </span>
            {% if log.returned %}
              <span class="badge">
                {{ log.returned|date:"Y/m/d H:i" }}
              </span>
            {% else %}
              <span class="badge badge-warning">借閱中</span>
            {% endif %}
          </div>
          <div>
            <a href="{% url 'reader_view' log.reader.id %}">
              {{ log.reader.realname }}
            </a>
          </div>
        </li>
        {% empty %}
        <li class="list-group-item">無</li>
        {% endfor %}
      </ul>
    </div>
  </div>