Django高校管理系统作业功能URL跳转异常：相对路径拼接错误排查

问题原因 #

核心问题出在全局基础模板base.html的侧边栏导航链接写法上：你使用了无前置斜杠的相对路径（比如href="studentattendancereport"、href="assignment"），浏览器解析相对路径时会自动拼接当前页面的父路径，所以当你处于/abc/pqr路径下时，点击链接就会跳转到/abc/xyz而不是根路径下的/xyz。
你其他功能没出问题大概率是因为那些功能页面都在根路径层级，没有嵌套路径，所以相对路径刚好没出问题，而作业详情页路径是/assignmentupload/xxx属于嵌套路径，就触发了这个问题。 #

修复方案 #

1. 修正base.html的侧边栏链接 #

所有内部链接统一使用Django的{% url %}模板标签生成绝对路径，替换原来的硬编码相对路径：

<!-- 替换前 -->
<a class=" nav-item nav-link {% if url_name == 'studentattendanceview'%}active{% endif %}"
    href="studentattendancereport">Attendance</a>
<a class="nav-item nav-link {% if url_name == 'studentattendanceview'%}active{% endif %}"
    href="marksreportstudent">Marks</a>
<a class="nav-item nav-link {% if url_name == 'assignment' or url_name == 'assignmentupload' %}active{% endif %}"
    href="assignment">Assignment</a>
<a class="nav-item nav-link {% if url_name == 'applyforleave'%}active{% endif %}"
    href="applyforleavestudent">Leave</a>

<!-- 替换后 -->
<a class=" nav-item nav-link {% if url_name == 'studentattendanceview'%}active{% endif %}"
    href="{% url 'studentattendancereport' %}">Attendance</a>
<a class="nav-item nav-link {% if url_name == 'studentattendanceview'%}active{% endif %}"
    href="{% url 'marksreportstudent' %}">Marks</a>
<a class="nav-item nav-link {% if url_name == 'assignment' or url_name == 'assignmentupload' %}active{% endif %}"
    href="{% url 'assignment' %}">Assignment</a>
<a class="nav-item nav-link {% if url_name == 'applyforleave'%}active{% endif %}"
    href="{% url 'applyforleavestudent' %}">Leave</a>

如果不想用{% url %}，也可以给所有硬编码路径加前置斜杠变成根相对路径，比如href="/assignment"，但更推荐用URL模板标签，后续改路径名不需要逐个改模板。

2. 补充修复其他隐藏问题 #

• cmsapp/urls.py路径加斜杠结尾：符合Django的路径规范，避免301重定向跳转的异常：

  path('assignment/', studentviews.assignments, name='assignment'),
  path('assignmentupload/<int:id>/', studentviews.assignment_upload, name='assignmentupload'),
  # 其他路径也统一加末尾斜杠
  

• assignment_report.html更新表单补全action：当前表单action为空，提交时会默认提交到当前页面路径，虽然当前场景可用，但显式写全更稳妥：

  <form action="{% url 'assignmentupload' assignment.id %}" method="POST" class="form-group" enctype="multipart/form-data">
  

• assignment_upload视图补充更新逻辑：现在的POST逻辑只支持新增提交，已提交作业的更新请求会触发重复提交报错，修改POST逻辑适配更新场景：

  def assignment_upload(request, id):
      assignment = Assignment.objects.get(id=id)
      student_id = Student.objects.get(admin=request.user.id)
      assignment_report = Student_Assignment.objects.filter(assignment_id=assignment.id, student_id=student_id).first()
      if request.method == 'POST':
          assignment_file = request.FILES['assignment']
          try:
              if assignment_report:
                  # 已提交就更新
                  assignment_report.document = assignment_file
                  assignment_report.save()
                  messages.success(request, '作业更新成功。')
              else:
                  # 未提交就新增
                  Student_Assignment.objects.create(assignment_id=assignment, student_id=student_id, document=assignment_file)
                  messages.success(request, '作业提交成功。')
              return redirect('assignment')
          except Exception as e:
              messages.error(request, '操作失败，请稍后重试。')
              return redirect('assignment')
      else:
          context = {'assignment':assignment, 'assignment_report':assignment_report, 'student_id':student_id}
          if assignment_report:    
              return render(request, 'cmsapp/student/assignment_report.html', context)
          else:
              return render(request, 'cmsapp/student/assignment_upload.html', context)
  

内容的提问来源于stack exchange，提问作者Akash Saingar