Django 小实例S1 简易学生选课管理系统 11 学生课程业务实现

Django 小实例S1 简易学生选课管理系统 第11节——学生课程业务实现
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作者自我介绍：b站小UP主，时常直播编程+红警三，python1对1辅导老师。

课程模块中，学生需要拥有的功能有：

• 查看课程列表
• 选课撤课
• 结课后评教

1 - 查看课程列表

学生可以按类别view_kind查看课程，view_kind分为

• current: 查看当前课程
• is_end: 查看结课课程
• select: 可选课的
• withdraw: 可撤课的

新建学生查看课程的模板templates/course/student/home.html如下

{% extends "course/nav.html" %}
{% block title %}HomePage{% endblock %}
{% block content %}
    <div class="main-container">
        <div class="main-bar">
            <form class="search-form" method="post">
                {% csrf_token %}
                <input class="input" id="search-key" type="text" name="search" {% if search_key != None %}value="{{ search_key }}" {% endif %}/>
                <input class="button" type="submit" value="搜索课程" />
            </form>

            {% if view_kind != "select"%}
                <input class="button right-button" type="button" value="选课"  onclick='window.open("{% url 'view_course' 'select' %}")' />
            {% endif %}
            {% if view_kind != "withdraw"%}
                <input class="button right-button" type="button" value="撤课"  onclick='window.open("{% url 'view_course' 'withdraw' %}")' />
            {% endif %}
            {% if view_kind != "is_end"%}
                <input class="button right-button" type="button" value="查看结课课程"  onclick='window.open("{% url 'view_course' 'is_end' %}")' />
            {% endif %}
            {% if view_kind != "current"%}
                <input class="button right-button" type="button" value="查看当前课程"  onclick='window.open("{% url 'view_course' 'current' %}")' />
            {% endif %}
        </div>
        <h3>{% if view_kind == "select"%}
                选课
            {% elif view_kind == "withdraw"%}
                撤课
            {% elif  view_kind == "is_end"%}
                查看结课课程
            {% elif view_kind == "current"%}
                查看当前课程
            {% endif %}</h3>
        <table class="item-list course-list">
            <thead>
                <tr>
                    <th class="course-no">课程编号</th>
                    <th class="course-name">名称</th>
                    <th class="course-credit">学分</th>
                    {% if view_kind == "is_end" %}
                        <th class="course-year-semester">年份学期</th>
                    {% else %}
                        <th class="course-number">当前人数/<br>最大人数</th>
                        <th class="course-year">年份</th>
                        <th class="course-semester">学期</th>
                    {% endif %}
                    <th class="course-teacher">教师</th>
                    {% if view_kind == "is_end" %}
                        <th class="course-scores">得分</th>
                        <th class="course-comments">评语</th>
                        <th class="course-rating">学生评分</th>
                        <th class="course-assessment">学生评价</th>
                        <th class="course-operation student-course">操作</th>
                    {% else %}
                        <th class="course-schedule">上课时间</th>
                        <th class="course-operation student-course">操作</th>
                    {% endif %}
                </tr>
            </thead>
            <tbody>
            {% if view_kind == "is_end" %}
                {# end course show student course #}
                {% for sc in course_list %}
                <tr id="course-id-{{ sc.course.id }}">
                    <td class="course-no">{{ sc.course.id }}</td>
                    <td class="course-name">{{ sc.course.name }}</td>
                    <td class="course-credit">{{ sc.course.credit }}</td>
                    <td class="course-year-semester">{{ sc.course.year }} {{ sc.course.get_semester_display }}</td>
                    <td class="course-teacher">{{ sc.course.teacher.name }}</td>
                    <td class="course-scores">{{ sc.scores }}</td>
                    <td class="course-comments">{{ sc.comments }}</td>
                    {% if sc.rating == None %}
                        <td class="course-rating">-</td>
                        <td class="course-assessment">-</td>
                        <td class="course-operation student-course">
                        <input class="button" type="button" value="查看详情" onclick='location.href="{% url 'sview_detail' sc.id%}"' />
                        <input class="button" type="button" value="评教"
                               onclick='window.open("{% url 'evaluate' sc.id %}")' />
                        </td>
                    {% else %}
                        <td class="course-rating">{{ sc.rating }}</td>
                        <td class="course-assessment">{{ sc.assessment }}</td>
                        <td class="course-operation student-course">
                        <input class="button" type="button" value="查看详情" onclick='location.href="{% url 'sview_detail' sc.id%}"' />
                        </td>
                    {% endif %}
                </tr>
                {% endfor %}
            {% else %}
                {% for course in course_list %}
                <tr id="course-id-{{ course.id }}">
                    <td class="course-no">{{ course.id }}</td>
                    <td class="course-name">{{ course.name }}</td>
                    <td class="course-credit">{{ course.credit }}</td>
                    <td class="course-number">{{ course.get_current_count }}/{{ course.max_number }}</td>
                    <td class="course-year">{{ course.year }}</td>
                    <td class="course-semester">{{ course.get_semester_display }}</td>
                    <td class="course-teacher">{{ course.teacher.name }}</td>
                    <td class="course-schedule">
                        {% for schedule in course.get_schedules %}
                            <div>{{ schedule }}</div>
                        {% endfor %}
                    </td>
                        <td class="course-operation student-course">
                        {% if view_kind == "select"%}
                            <input class="button" type="button" value="选课"
                                   onclick='window.open("{% url 'operate_course' course.id 'select' %}")' />
                        {% endif %}
                        {% if view_kind == "withdraw"%}
                            <input class="button" type="button" value="撤课"
                                   onclick='window.open("{% url 'operate_course' course.id 'withdraw' %}")' />
                        {% endif %}
                        {% if view_kind == "current"%}
                            -
                        {% endif %}
                        </td>
                </tr>
                {% endfor %}
            {% endif %}
            </tbody>

        </table>
    </div>
{% endblock %}

然后在course/views.py中添加代码如下

def view_course(request, view_kind):
    """
    :param view_kind:
        current: 查看当前课程
        is_end: 查看结课课程
        select: 选课
        withdraw: 撤课
    """
    user = get_user(request, "student")
    if not user:
        return redirect(reverse("login", kwargs={"kind": "student"}))

    is_search = False
    search_key = ""
    if request.method == "POST":
        search_key = request.POST.get("search")
        if search_key:
            is_search = True

    info = {
        "name": user.name,
        "kind": "student",
    }

    course_list = []

    if view_kind in ["select", "current", "withdraw", "is_end"]:
        if view_kind == "select":
            q = Q(status=2)
            if is_search:
                q = q & (Q(name__icontains=search_key) | Q(teacher__name__icontains=search_key))

            course_list = Course.objects.filter(q)

            my_course = StudentCourse.objects.filter(Q(student=user) & Q(with_draw=False))
            my_cids = [c.course.id for c in my_course]
            course_list = [c for c in course_list if c.id not in my_cids]
        else:
            q = Q(student=user) & Q(with_draw=False)
            if is_search:
                q = q & (Q(name__icontains=search_key) | Q(teacher__name__icontains=search_key))
            my_course = StudentCourse.objects.filter(q)
            if view_kind == "current":
                course_list = [c.course for c in my_course if c.course.status < 4]
            elif view_kind == "withdraw":
                course_list = [c.course for c in my_course if c.course.status == 2]
            elif view_kind == "is_end":
                course_list = [c for c in my_course if c.course.status >= 4]

    else:
        return HttpResponse(INVALID_REQUEST_METHOD)

    context = {
        'info': info,
        'view_kind': view_kind,
        'course_list': course_list
    }
    if is_search:
        context["search_key"] = search_key

    return render(request, 'course/student/home.html', context)

课程主页即学生的个人主页，故修改course/views.py中的原视图方法student_home为

def student_home(request):
    return redirect(reverse("view_course", kwargs={"view_kind": "current"}))

2 - 选课撤课

选课是新建一个学生课程关系记录，撤课则是修改对应的学生课程关系记录。
即学生有两种操作课程方法，operate_kind如下：

• select: 选课
• withdraw: 撤课

如果网页请求发送的方法不在这两种里面，则不符合规范，同时需要将这一信息通过响应返回告知浏览器。
故在constants.py中添加ILLEGAL_KIND = "Illegal kind for you."

在course/views.py中，导入ILLEGAL_KIND，然后添加代码如下

# 在开头导入timezone
from django.utils import timezone

def operate_course(request, operate_kind, course_id):
    """
    :param operate_kind:
        select: 选课
        withdraw: 撤课
    """
    user = get_user(request, "student")
    if not user:
        return redirect(reverse("login", kwargs={"kind": "student"}))

    if operate_kind not in ["select", "withdraw"]:
        return HttpResponse(ILLEGAL_KIND)
    elif operate_kind == "select":
        course = Course.objects.filter(pk=course_id).get()
        new_course = StudentCourse(student=user, course=course)
        new_course.save()
    elif operate_kind == "withdraw":
        q = Q(course__id=course_id) & Q(student=user) & Q(with_draw=False)
        course = StudentCourse.objects.filter(q).get()
        course.with_draw = True
        course.with_draw_time = timezone.now()
        course.save()

    return redirect(reverse("view_course", kwargs={"view_kind": operate_kind}))

3 - 结课后评教

学生给老师评教和老师给学生评分的后端逻辑是一样的，都是修改学生课程关系表内的数据。

先在course/forms.py中添加

class RateForm(forms.ModelForm):
    class Meta:
        model = StudentCourse
        fields = ["course", "scores", "comments", "rating", "assessment"]

    course = forms.CharField(label="课程", disabled=True)
    scores = forms.IntegerField(label="成绩", disabled=True)
    comments = forms.CharField(label="老师评价", disabled=True)

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.initial['course'] = self.instance.course
        self.initial['scores'] = self.instance.scores
        self.initial['comments'] = self.instance.comments

    def clean_course(self):
        return self.initial['course']

    def clean_scores(self):
        return self.initial['scores']

    def clean_comments(self):
        return self.initial['comments']

然后添加模板文件templates/course/student/rating.html：

{% extends "course/nav.html" %}
{% block title %}评教{% endblock %}
{% block content %}
    <h3>评教</h3>
    <div class="form create-update-from">
        <form method="post">
            {% csrf_token %}
            {{form.as_p}}
            <div class="submit-button">
                <input type="submit" value="确定"/>
                <input type="button" value="返回" onclick='location.href="{{ return_url }}"' />
            </div>
        </form>
    </div>
{% endblock %}

再在course/cbvs.py中导入RateForm类，然后添加代码如下

class RateUpdateView(UpdateView):
    model = StudentCourse
    form_class = RateForm
    template_name = 'course/student/rating.html'

    def get(self, request, *args, **kwargs):
        self.object = self.get_object()

        info = {}
        return_url = reverse("view_course", kwargs={"view_kind": "is_end"})
        if self.object:
            student = self.object.student
            info = {
                "name": student.name,
                "kind": "student",
            }

        return self.render_to_response(self.get_context_data(info=info, return_url=return_url))

    def get_success_url(self):
        return reverse("view_course", kwargs={"view_kind": "is_end"})

4 - 学生课程详情页

这个使用CBVs实现起来最快
先添加模板templates/course/student/course.html如下

{% extends "course/nav.html" %}
{% block title %}课程详情{% endblock %}
{% block content %}
    <h3>课程详情</h3>
    <ul class="course-details">
        <li class="course-detail"><span class="detail-name">课程编号</span> {{ object.course.id }}</li>
        <li class="course-detail"><span class="detail-name">课程名</span> {{ object.course.name }}</li>
        <li class="course-detail"><span class="detail-name">学分</span> {{ object.course.credit }}</li>
        <li class="course-detail"><span class="detail-name">课程人数/最大人数</span> {{ object.course.get_current_count }}/{{ object.course.max_number }}</li>
        <li class="course-detail"><span class="detail-name">年份</span> {{ object.course.year }}</li>
        <li class="course-detail"><span class="detail-name">学期</span> {{ object.course.get_semester_display }}</li>

        <li class="course-detail"><span class="detail-name">教师</span> {{ object.course.teacher.name }}</li>
        <li class="course-detail"><span class="detail-name">上课时间</span>
            <span class="course-schedules">
            {% for schedule in object.course.get_schedules %}
                <div class="course-schedule">{{ schedule }}</div>
                <div class="course-schedule">{{ schedule }}</div>
            {% endfor %}
            </span>
        </li>
        <li class="course-detail"><span class="detail-name">得分</span>
            {% if object.scores != None %}{{ object.scores }}{% else %} - {% endif %}
        </li>
        <li class="course-detail"><span class="detail-name">评语</span>
            {% if object.comments != None %}{{ object.comments }}{% else %} - {% endif %}
        </li>
        <li class="course-detail"><span class="detail-name">学生评分</span>
            {% if object.rating != None %}{{ object.rating }}{% else %} - {% endif %}
        </li>
        <li class="course-detail"><span class="detail-name">学生评价</span>
            {% if object.assessment != None %}{{ object.assessment }}{% else %} - {% endif %}
        </li>

    </ul>
    <input type="button" value="返回" onclick='location.href="{% url 'view_course' 'is_end'%}"' />
{% endblock %}

再在course/cbvs.py中添加代码如下

class StudentCourseDetailView(DetailView):
    model = StudentCourse
    template_name = 'course/student/course.html'

    def get(self, request, *args, **kwargs):
        self.object = self.get_object()
        context = self.get_context_data(object=self.object)
        if self.object:
            context["info"] = {
                "name": self.object.student.name,
                "kind": "student",
            }
        return self.render_to_response(context)

5 - 添加路由

上面已经把学生需要的视图方法全部实现完毕了，接下来就是添加到路由里面。
修改后的course/urls.py如下

from django.urls import path
from course.views import *
from course.cbvs import ScoreUpdateView, RateUpdateView, StudentCourseDetailView


urlpatterns = [
    path('<slug:kind>/', home, name="course"),
    path('teacher/create_course', create_course, name="create_course"),
    path('teacher/view_detail/<int:course_id>', view_detail, name="view_detail"),
    path('teacher/create_schedule/<int:course_id>', create_schedule, name="create_schedule"),
    path('teacher/delete_schedule/<int:schedule_id>', delete_schedule, name="delete_schedule"),
    path('teacher/score/<int:pk>', ScoreUpdateView.as_view(), name="score"),
    path('teacher/handle_course/<int:course_id>/<int:handle_kind>', handle_course, name="handle_course"),

    path('student/view/<slug:view_kind>', view_course, name="view_course"),
    path('student/operate/<int:course_id>/<slug:operate_kind>', operate_course, name="operate_course"),

    path('student/evaluate/<int:pk>', RateUpdateView.as_view(), name="evaluate"),
    path('student/view_detail/<int:pk>', StudentCourseDetailView.as_view(), name="sview_detail"),
]

6 - 效果

选课页面

当前课程页面