Forms组件

Django提供的用于数据校验和模板渲染的组件

校验字段功能

from django.forms import widgets

# forms使用bootstrap样式
# widget=widgets.EmailInput(attrs={'class':'form-control'})

wid_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())

总结：

在项目中创建一个py文件

1 写一个类继承Form
2 在类中写属性,写的属性,就是要校验的字段
3 使用:生成一个你写的类的对象myform,把要校验的数据(字典),传到对象中:MyForm(字典)
-数据多?数据少?数据多可以,少不行(required控制)
4 myform.is_valid() 是True表示所有字段都通过校验
5 myform.cleaned_data:是一个字典,所有通过校验的数据放在里面
6 myform.errors:是一个字典,所有的错误字段的信息

在模板中:

{{myform.name}}
{%for item in myform%}
{{item.label}}:{{item}}
{%endfor%}
myform.as_table/as_p/as_ul(不推荐使用)

渲染标签功能

方式一：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
   <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>
<h3>注册页面</h3>
<div class="container">
    <div class="row">
        <div class="col-md-6 col-lg-offset-3">

                <form action="" method="post">
                    {% csrf_token %}
                    <div>
                        <label for="">用户名</label>
                        {{ form.name }}
                    </div>
                    <div>
                        <label for="">密码</label>
                        {{ form.pwd }}
                    </div>
                    <div>
                        <label for="">确认密码</label>
                        {{ form.r_pwd }}
                    </div>
                    <div>
                        <label for=""> 邮箱</label>
                        {{ form.email }}
                    </div>

                    <input type="submit" class="btn btn-default pull-right">
                </form>
        </div>
    </div>
</div>
</body>
</html>

方式二：

<form action="" method="post">
                    {% csrf_token %}

                    {% for field in form %}
                        <div>
                            <label for="">{{ field.label }}</label>
                            {{ field }}
                        </div>
                    {% endfor %}
                    <input type="submit" class="btn btn-default pull-right">

</form>

方式三：

<form action="" method="post">
    {% csrf_token %}

    {{ form.as_p }}
    <input type="submit" class="btn btn-default pull-right">
</form>

渲染错误信息功能

视图函数

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 render(request,"register.html",locals())
    form=UserForm()
    return render(request,"register.html",locals())

模板

<form action="" method="post" novalidate>
    {% csrf_token %}

    {% for field in form %}
        <div>
            <label for="">{{ field.label }}</label>
            {{ field }} <span class="pull-right" style="color: red">{{ field.errors.0 }}</span>
        </div>
    {% endfor %}
    <input type="submit" class="btn btn-default">
</form>

组件的参数配置

class Ret(Form):
    name = forms.CharField(max_length=10, min_length=2, label='用户名',error_messages={'required': '该字段不能为空', 'invalid': '格式错误', 'max_length': '太长','min_length': '太短'},
    widget=widgets.TextInput(attrs={'class':'form-control'}))
    pwd = forms.CharField(max_length=10, min_length=2, widget=widgets.PasswordInput(attrs={'class':'form-control'}))
    email = forms.EmailField(label='邮箱', error_messages={'required': '该字段不能为空', 'invalid': '格式错误'})

局部钩子

from django.core.exceptions import NON_FIELD_ERRORS, ValidationError
def clean_name(self):

        val=self.cleaned_data.get("name")

        ret=UserInfo.objects.filter(name=val)

        if not ret:
            return val
        else:
            raise ValidationError("该用户已注册!")

    def clean_tel(self):

        val=self.cleaned_data.get("tel")

        if len(val)==11:

            return val
        else:
            raise  ValidationError("手机号格式错误")

全局钩子

def clean(self):
        pwd=self.cleaned_data.get('pwd')
        r_pwd=self.cleaned_data.get('r_pwd')

        if pwd and r_pwd:
            if pwd==r_pwd:
                return self.cleaned_data
            else:
                raise ValidationError('两次密码不一致')
        else:

            return self.cleaned_data