22、Django实战第22天：课程评论

class CourseCommentView(LoginRequiredMixin, View):
    def get(self, request, course_id):
        course = Course.objects.get(id=course_id)
        return render(request, ‘course-comment.html‘, {
            ‘course‘: course,
        })

...
from .views import  CourseCommentView


urlpatterns = [
    ...
    url(r‘comment/(?P<course_id>\d+)/$‘, CourseCommentView.as_view(), name=‘course_comment‘),
    

]

class CourseCommentView(LoginRequiredMixin, View):
    def get(self, request, course_id):
        course = Course.objects.get(id=course_id)
        all_resource = CourseResource.objects.filter(course=course)

        # 查询用户是否已经关联了该数据
        user_course = UserCourse.objects.filter(user=request.user, course=course)
        if not user_course:
            # 如果没有则写入数据库
            my_course = UserCourse(user=request.user, course=course)
            my_course.save()

        # 该同学还学过
        user_courses = UserCourse.objects.filter(course=course) #获取“用户课程”表里面该课程的所有记录
        user_ids = [user_course.user.id for user_course in user_courses] #获取学过该课程的所有用户id
        all_user_courses = UserCourse.objects.filter(user_id__in=user_ids) #获取这些用户学过的课程记录
        course_ids = [user_course.id for user_course in all_user_courses] #获取这些课程的id
        relate_courses = Course.objects.filter(id__in=course_ids).order_by(‘-click_nums‘)[:5] #根据点击量取出5个
        return render(request, ‘course-comment.html‘, {
            ‘course‘: course,
            ‘all_resource‘: all_resource,
            ‘relate_courses‘: relate_courses,
        })

...
from operation.models import CourseComments
from django.http import HttpResponse


class AddCommentView(View):
    def post(self, request):
        if not request.user.is_authenticated():
            # 判断用户登录状态
            return HttpResponse(‘{"status":"fail", "msg":"用户未登录"}‘, content_type=‘application/json‘)

        course_id = request.POST.get(‘course_id‘, 0)
        comments = request.POST.get(‘comments‘, ‘‘)
        if int(course_id) > 0 and comments:
            course_comments = CourseComments()
            course = Course.objects.get(id=int(course_id))
            course_comments.course = course
            course_comments.comments = comments
            course_comments.user = request.user
            course_comments.save()
            return HttpResponse(‘{"status":"success", "msg":"添加成功"}‘, content_type=‘application/json‘)
        else:
            return HttpResponse(‘{"status":"fail", "msg":"添加失败"}‘, content_type=‘application/json‘)

...
from .views import AddCommentView


urlpatterns = [
    ...
    url(r‘add_comment/$‘, AddCommentView.as_view(), name=‘add_comment‘),


]

class Course(models.Model):
    name = models.CharField(max_length=50, verbose_name=‘课程名‘)
    course_org = models.ForeignKey(CourseOrg, verbose_name=‘课程机构‘)
    desc = models.CharField(max_length=300, verbose_name=‘课程描述‘)
    details = models.TextField(verbose_name=‘课程详情‘)
    degree = models.CharField(verbose_name=‘课程难度‘, choices=((‘cj‘, ‘初级‘), (‘zj‘, ‘中级‘), (‘gj‘, ‘高级‘)), max_length=2)
    learn_times = models.IntegerField(default=0, verbose_name=‘学习时长（分钟）‘)
    students = models.IntegerField(default=0, verbose_name=‘学习人数‘)
    fav_nums = models.IntegerField(default=0, verbose_name=‘收藏人数‘)
    image = models.ImageField(upload_to=‘courses/%Y/%m‘, verbose_name=‘封面图‘, max_length=100)
    click_nums = models.IntegerField(default=0, verbose_name=‘点击数‘)
    category = models.CharField(max_length=10, verbose_name=u‘类别‘, default=‘‘)
    tag = models.CharField(max_length=10, verbose_name=u‘标签‘, default=‘‘)
    teacher = models.ForeignKey(Teacher, verbose_name=‘课程讲师‘, null=True, blank=True)
    youneed_know = models.CharField(default=‘‘, max_length=300, verbose_name=‘课程须知‘)
    teacher_tell = models.CharField(default=‘‘, max_length=300, verbose_name=‘你能学到‘)
    add_time = models.DateTimeField(default=datetime.now, verbose_name=‘添加时间‘)

    class Meta:
        verbose_name = ‘课程‘
        verbose_name_plural = verbose_name

    def get_lesson_nums(self):
        """获取章节数"""
        return self.lesson_set.count()

    def get_lesson(self):
        """获取章节"""
        return self.lesson_set.all()

    def get_students(self):
        """获取3个学习用户"""
        return self.usercourse_set.all()[:3]
    
    def get_comment(self):
        """获取评论"""
        return self.coursecomments_set.all()

    def __str__(self):
        return self.name