class TeacherForm(Form):  #必须继承Form

    # 创建字段，本质上是正则表达式

    username = fields.CharField(

        required=True,     #必填字段

        error_messages={"required":"用户名不能为空！！"},  #显示中文错误提示

        widget=widgets.TextInput(attrs={"placeholder":"用户名","class":"form-control"}),  #自动生成input框

        label="姓名",

        label_suffix=":"

       )

    password = fields.CharField(required=True, error_messages={'required': '密码不能为空'},

                                widget=widgets.PasswordInput(attrs={'placeholder': '密码', 'class': 'form-control'}),

                                label="密码",

                                label_suffix=":"

      )  # 不能为空

    email = fields.EmailField(

        required=True,

        error_messages={"required":"邮箱不能为空！！","invalid":"无效的邮箱"},

        widget=widgets.EmailInput(attrs={"placeholder": "邮箱", "class": "form-control"}),  # 自动生成input框

        label = "邮箱",

        label_suffix = ":"

    ) #不能为空且邮箱格式要一致

from django.core.exceptions import ValidationError

from django.conf import settings

def editteacher(request,nid):

    obj = models.UserInfo.objects.filter(id=nid, ut_id=1).first()

    # print(obj.username)

    if not obj:

        return redirect("/teacherindex/")

    if request.method=="GET":

        print([obj.id for obj in obj.teacher_classes.all()])  #[2]  拿到select框的id是为了要做默认显示的

        form = TeacherForm(initial={"username":obj.username,"password":obj.password,"email":obj.email,"teacher_classes":[obj.id for obj in obj.teacher_classes.all()]}) #就让显示一个input框，并且带有原来哪一行的内容

        return render(request, "editteacher.html", {"form":form})

    else:

        form = TeacherForm(data=request.POST)

        if form.is_valid():#开始校验,注意这要加括号

            cls_list = form.cleaned_data.pop("teacher_classes")

            print(cls_list)

            models.UserInfo.objects.filter(id=nid).update(**form.cleaned_data)

            obj.teacher_classes.set(cls_list)   #更新第三张表

            return redirect("/teacherindex/")

        else:

            return render(request, "editteacher.html", {"form":form})

def addteacher(request):

    if request.method=="GET":

        form = TeacherForm()  #只是让显示一个input框

        return render(request, "addteacher.html", {"form":form})

    else:

        form = TeacherForm(data=request.POST)

        # print(form)  #<QuerySet [<UserInfo: UserInfo object>, <UserInfo: UserInfo object>, <UserInfo: UserInfo object>]>

        if form.is_valid():# 开始验证

            # print('执行成功',form.cleaned_data)          # 所有匹配成功，字典

            # # {'username': 'ghf', 'password': '435', 'email': 'fddfg@qq.com', 'teacher_classes': ['4']}

            cls_list = form.cleaned_data.pop("teacher_classes")

            print("============id",cls_list)

            form.cleaned_data['ut_id'] = 1

            #创建新老师的对象

            teacher_obj = models.UserInfo.objects.create(**form.cleaned_data)

            #创建新老师和班级的关系

            teacher_obj.teacher_classes.add(*cls_list)  #以前添加的是对象，现在也可以吧id添加进去

            return redirect("/teacherindex/")

        else:

            # print("=====?",form.errors,type(form.errors))#返回失败的结果

            # print(form.errors["username"][0])   #拿到返回失败的结果，渲染到页面

            return render(request, "addteacher.html", {"form":form})