Form组件
服务端假设所有用户提交的数据都是不可信任的,所以Django框架内置了form组件来验证用户提交的信息
form组件的2大功能:
1 验证(显示错误信息)
2 保留用户上次输入的信息 3.可以生成html标签
1 验证(显示错误信息)
示例/:注册用户字段校验
模型:models.py:
class UserInfo(models.Model): name=models.CharField(max_length=32) pwd=models.CharField(max_length=32) email=models.EmailField() tel=models.CharField(max_length=32)
模板: register.html:
Title
视图函数:register:
# forms组件from django.forms import widgetswid_01=widgets.TextInput(attrs={ "class":"form-control"})wid_02=widgets.PasswordInput(attrs={ "class":"form-control"})class UserForm(forms.Form): name=forms.CharField(max_length=32, widget=wid_01 ) pwd=forms.CharField(max_length=32,widget=wid_02) r_pwd=forms.CharField(max_length=32,widget=wid_02) email=forms.EmailField(widget=wid_01) tel=forms.CharField(max_length=32,widget=wid_01)def register(request): if request.method=="POST": form=UserForm(request.POST) if form.is_valid(): print(form.cleaned_data) # 所有干净的字段以及对应的值 else: print(form.cleaned_data) # print(form.errors) # ErrorDict : {"校验错误的字段":["错误信息",]} print(form.errors.get("name")) # ErrorList ["错误信息",] return HttpResponse("OK") form=UserForm() return render(request,"register.html",locals())
其中视图函数中关于Widgets的详细使用,可参考:
2. -- 可以生成html标签
生成HTML 标签有三种渲染方式
1. 渲染成文字段落as_p()
Form.as_p()
该方法将form渲染成一系列<p>
标签,每个<p>
标签包含一个字段;
2.渲染方式二循环form表单,利用字段:
rm action="" method="post"> {% csrf_token %} {% for field in form %}{ { field }}{% endfor %}
3.渲染方式三:
3.返回并在界面表示错误
HTML示例:
增加全局钩子和局部钩子的代码示例:
views:
from django.shortcuts import render,HttpResponsefrom django import forms# Create your views here.from django.forms import widgetsfrom django.core.exceptions import ValidationErrorwid_01=widgets.TextInput(attrs={ "class":"form-control"})wid_02=widgets.PasswordInput(attrs={ "class":"form-control"})class UserForm(forms.Form): name=forms.CharField(max_length=32, widget=wid_01 ) pwd=forms.CharField(max_length=32,widget=wid_02) r_pwd=forms.CharField(max_length=32,widget=wid_02) email=forms.EmailField(widget=wid_01) tel=forms.CharField(max_length=32,widget=wid_01) # 局部钩子 def clean_name(self): val = self.cleaned_data.get("name") if not val.isdigit(): return val else: raise ValidationError("用户名不能是纯数字!") # 全局钩子 def clean(self): pwd = self.cleaned_data.get("pwd") r_pwd = self.cleaned_data.get("r_pwd") if pwd == r_pwd: return self.cleaned_data else: raise ValidationError('两次密码不一致!')def register(request): if request.method=="POST": form=UserForm(request.POST) if form.is_valid(): print(form.cleaned_data) # 所有干净的字段以及对应的值 else: clean_error = form.errors.get("__all__") print(form.cleaned_data) # print(form.errors) # ErrorDict : {"校验错误的字段":["错误信息",]} print(form.errors.get("name")) # ErrorList ["错误信息",] return render(request, "register.html", locals()) return HttpResponse("OK") form=UserForm() return render(request,"register.html",locals())
html:
以下几种form表单渲染方式示例,请详看:
# 通过直接form生成的HTML文件如下## 渲染后:# # 通过直接form.as_p生成的HTML文件如下# # 渲染后:# # 直接{ { form }}虽然好,啥都不用操心,但是往往并不是你想要的,比如你要使用CSS和JS,比如你要引入Bootstarps框架,这些都需要对表单内的input元素进行额外控制,那怎么办呢?手动渲染字段就可以了。# 可以通过{ { form.name_of_field }}获取每一个字段,然后分别渲染,如下例所示:# { { form.non_field_errors }}#
# { { form.subject.errors }}# # { { form.subject }}#
# # { { form.message.errors }}# # { { form.message }}#
# # { { form.sender.errors }}# # { { form.sender }}#
# # { { form.cc_myself.errors }}# # { { form.cc_myself }}#
# 渲染后:# < div class ="fieldWrapper" ># < label for ="id_subject" > Email subject:# < input type = "text" name = "subject" maxlength = "100" required = "" id = "id_subject" ># ## < div class ="fieldWrapper" ># < labelfor ="id_message" > Your message:< / label ># < textarea name = "message" cols = "40" rows = "10" required = "" id = "id_message" > < / textarea ># ## < div class ="fieldWrapper" ># < label for ="id_sender" > Your email address:< / label ># < input type = "email" name = "sender" required = "" id = "id_sender" ># ## #
# 4. 循环表单的字段:# 如果你的表单字段有相同格式的HMTL表现,那么完全可以循环生成,不必要手动的编写每个字段,减少冗余和重复代码,只需要使用模板语言中的{% for %}循环,如下所示:# {% for field in form %}# # { { field.errors }}# { { field.label_tag }} { { field }}# {% if field.help_text %}#
# {% endfor %} {
{ field.help_text|safe }}# {% endif %}#
{
{ field }}
中非常有用的属性,这些都是Django内置的模板语言给我们提供的方便:
属性 说明{ { field.label }} 字段对应的label信息{ { field.label_tag }} 自动生成字段的label标签,注意与{ { field.label }}的区别。{ { field.id_for_label }} 自定义字段标签的id{ { field.value }} 当前字段的值,比如一个Email字段的值someone@example.com{ { field.html_name }} 指定字段生成的input标签中name属性的值{ { field.help_text }} 字段的帮助信息{ { field.errors }} 包含错误信息的元素{ { field.is_hidden }} 用于判断当前字段是否为隐藏的字段,如果是,返回True{ { field.field }} 返回字段的参数列表。例如{ { char_field.field.max_length }}
详细可参考: 或
刘江博客: