Django之Form组件补充

1、定义的规则

class TeacherForm(Form):  #必须继承Form
    # 建立字段，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

 

页面上渲染

用第二种方式须要加上下面的这个：

 2、下拉框的规则

 

3、判断用户民是不存在，存在就不添加了

须要导入：

from django.core.exceptions import ValidationError

、

4、initial  修改时用到

 

5、自定义配置

一、在settings中：

二、导入settings

from django.conf import settings

 三、使用

 6、多对多修改两种方式（用Form）

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是为了要作默认显示的
        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，而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})

 

 

7、多对多添加（用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) # 全部匹配成功，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
            #建立新老师的对象
            teacher_obj = models.UserInfo.objects.create(**form.cleaned_data) #建立新老师和班级的关系
            teacher_obj.teacher_classes.add(*cls_list)  #之前添加的是对象，如今也能够吧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})