Django (Form)

一. Form 

#功能:
#	- 对用户提交的数据进行验证
#	- 保留上次输入内容
#	- 生成HTML标签

#创建Form类时,主要涉及到 字段 和 插件
#     - 字段用于对用户请求数据的验证
#     - 插件用于自动生成HTML 

二. Form 内置字段

Field
    required=True,               是否允许为空
    widget=None,                 HTML插件
    label=None,                  用于生成Label标签或显示内容
    initial=None,                初始值
    help_text='',                帮助信息(在标签旁边显示)
    error_messages=None,         错误信息 {'required': '不能为空', 'invalid': '格式错误'}
    show_hidden_initial=False,   是否在当前插件后面再加一个隐藏的且具有默认值的插件(可用于检验两次输入是否一直)
    validators=[],               自定义验证规则
    localize=False,              是否支持本地化
    disabled=False,              是否可以编辑
    label_suffix=None            Label内容后缀
 
 
CharField(Field)
    max_length=None,             最大长度
    min_length=None,             最小长度
    strip=True                   是否移除用户输入空白
 
IntegerField(Field)
    max_value=None,              最大值
    min_value=None,              最小值
 
FloatField(IntegerField)
    ...
 
DecimalField(IntegerField)
    max_value=None,              最大值
    min_value=None,              最小值
    max_digits=None,             总长度
    decimal_places=None,         小数位长度
 
BaseTemporalField(Field)
    input_formats=None          时间格式化   
 
DateField(BaseTemporalField)    格式:2015-09-01
TimeField(BaseTemporalField)    格式:11:12
DateTimeField(BaseTemporalField)格式:2015-09-01 11:12
 
DurationField(Field)            时间间隔:%d %H:%M:%S.%f
    ...
 
RegexField(CharField)
    regex,                      自定制正则表达式
    max_length=None,            最大长度
    min_length=None,            最小长度
    error_message=None,         忽略,错误信息使用 error_messages={'invalid': '...'}
 
EmailField(CharField)      
    ...
 
FileField(Field)
    allow_empty_file=False     是否允许空文件
 
ImageField(FileField)      
    ...
    注:需要PIL模块,pip3 install Pillow
    以上两个字典使用时,需要注意两点:
        - form表单中 enctype="multipart/form-data"
        - view函数中 obj = MyForm(request.POST, request.FILES)
 
URLField(Field)
    ...
 
 
BooleanField(Field)  
    ...
 
NullBooleanField(BooleanField)
    ...
 
ChoiceField(Field)
    ...
    choices=(),                选项,如:choices = ((0,'上海'),(1,'北京'),)
    required=True,             是否必填
    widget=None,               插件,默认select插件
    label=None,                Label内容
    initial=None,              初始值
    help_text='',              帮助提示
 
 
ModelChoiceField(ChoiceField)
    ...                        django.forms.models.ModelChoiceField
    queryset,                  # 查询数据库中的数据
    empty_label="---------",   # 默认空显示内容
    to_field_name=None,        # HTML中value的值对应的字段
    limit_choices_to=None      # ModelForm中对queryset二次筛选
     
ModelMultipleChoiceField(ModelChoiceField)
    ...                        django.forms.models.ModelMultipleChoiceField
 
 
     
TypedChoiceField(ChoiceField)
    coerce = lambda val: val   对选中的值进行一次转换
    empty_value= ''            空值的默认值
 
MultipleChoiceField(ChoiceField)
    ...
 
TypedMultipleChoiceField(MultipleChoiceField)
    coerce = lambda val: val   对选中的每一个值进行一次转换
    empty_value= ''            空值的默认值
 
ComboField(Field)
    fields=()                  使用多个验证,如下:即验证最大长度20,又验证邮箱格式
                               fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),])
 
MultiValueField(Field)
    PS: 抽象类,子类中可以实现聚合多个字典去匹配一个值,要配合MultiWidget使用
 
SplitDateTimeField(MultiValueField)
    input_date_formats=None,   格式列表:['%Y--%m--%d', '%m%d/%Y', '%m/%d/%y']
    input_time_formats=None    格式列表:['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']
 
FilePathField(ChoiceField)     文件选项,目录下文件显示在页面中
    path,                      文件夹路径
    match=None,                正则匹配
    recursive=False,           递归下面的文件夹
    allow_files=True,          允许文件
    allow_folders=False,       允许文件夹
    required=True,
    widget=None,
    label=None,
    initial=None,
    help_text=''
 
GenericIPAddressField
    protocol='both',           both,ipv4,ipv6支持的IP格式
    unpack_ipv4=False          解析ipv4地址,如果是::ffff:192.0.2.1时候,可解析为192.0.2.1, PS:protocol必须为both才能启用
 
SlugField(CharField)           数字,字母,下划线,减号(连字符)
    ...
 
UUIDField(CharField)           uuid类型
    ...
View Code

a. 字段分类: 

1. 验证

#required
#error_messages
class TestForm(Form):
    t1 = fields.CharField(
        required=True,
        max_length=8,
        min_length=2,
        error_messages={
            "required":"不能为空",
            "max_length":"太长",
            "min_length":"太短",
        }
    )
    t2 = fields.IntegerField(
        min_value=10,
        max_value=1000,
        error_messages={
            "required": "t2不能为空",
            "invalid":"t2格式错误,必须是数字",
            "min_value":"必须大于10",
            "max_value":"必须小于1000",
        }
    )

    t3 = fields.EmailField(
        error_messages={
            "required": "t3不能为空",
            "invalid": "t3格式错误,必须是邮箱格式",
        }
    )
    t4 = fields.URLField()
    t5 = fields.SlugField()
    t6 = fields.GenericIPAddressField()
    t7 = fields.DateField()
    t8 = fields.DateTimeField()
    t9 = fields.RegexField("139d+")
View Code

2. 生成html标签

Field
    widget=None,                 HTML插件
    label=None,                  用于生成Label标签或显示内容
    initial=None,                初始值
    help_text='',                帮助信息(在标签旁边显示)
    show_hidden_initial=False,   是否在当前插件后面再加一个隐藏的且具有默认值的插件(可用于检验两次输入是否一直)
    disabled=False,              是否可以编辑
    label_suffix=None            Label内容后缀
############# views.py

class TestForm(Form):
    t1 = fields.CharField(
        label="用户名",
        label_suffix=":",       #label内容后缀   前端写obj.as_p才显示
        help_text="....",       #提供帮助信息
        initial="666",
        required=True,
        max_length=8,
        min_length=2,
        error_messages={
            "required":"不能为空",
            "max_length":"太长",
            "min_length":"太短",
        }
    )


def test(request):
    if request.method == "GET":
        obj = TestForm()
        return render(request,"test.html",{"obj":obj})
    else:
        obj = TestForm(request.POST)
        if obj.is_valid():
            print(obj.cleaned_data)
        else:
            print(obj.errors)
        return render(request, "test.html")



#前端  html  两种方式显示

#方式一:
<form action="/test/" method="POST">
    {% csrf_token %}
    {{ obj.t1.label }}{{ obj.t1.label_suffix }}
    {{ obj.t1 }}{{ obj.t1.help_text }}
    <input type="submit" value="提交">
</form>

方式二:
<form action="/test/" method="POST">
    {% csrf_token %}
    {{ obj.as_p }}
    <input type="submit" value="提交">
</form>
示例演示

保留上次提交的内容:

#obj = TestForm()
#obj.t1  <input type="text" name=t1/>

#obj = TestForm(request.POST)
#obj.t2  <input type="text" name=t1 values="xxx" />
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<form action="/test/" method="POST" novalidate>
    {% csrf_token %}
    <p>
        {{ obj.t1 }}{{ obj.errors.t1.0 }}
    </p>
    <p>
        {{ obj.t2 }}{{ obj.errors.t2.0 }}
    </p>
    <input type="submit" value="提交">
</form>




</body>
</html>
test.html
from django.shortcuts import render,HttpResponse

# Create your views here.
from django.forms import Form,fields


class TestForm(Form):
    t1 = fields.CharField(required=True,max_length=8,min_length=2,
        error_messages={
            "required":"不能为空",
            "max_length":"太长",
            "min_length":"太短",
        }
    )

    t2 = fields.EmailField()

def test(request):
    if request.method == "GET":
        obj = TestForm()        #没有参数,相当于去创建 #input等标签,<input type="text" name="t2">,没有value
        return render(request,"test.html",{"obj":obj})
    else:
        obj = TestForm(request.POST)    #取到数据
        if obj.is_valid():
            print(obj.cleaned_data)
        else:
            print(obj.errors)
        return render(request, "test.html",{"obj":obj}) #<input type="text" name="t2" value="xx">
View.py

b. Form类参数验证:  

#obj = xxForm({"title":"全栈一期"})		#默认第一个参数是data,要验证
#obj = xxForm(data = {"title":"全栈一期"})	#参数data要验证,有错误前端会提示 obj.errors.title.0
#obj = xxForm(request.POST)			#request.POST默认是data = request.POST

#obj = xxForm(initial = {"title":"全栈一期"})	#initial  #不验证

三. Form 插件 

a. Select框:

#单选
cls_id = fields.IntegerField(
    # widget=widgets.Select(choices=[(1,'上海'),(2,'北京')])
    widget=widgets.Select(choices=models.Classes.objects.values_list('id','title'))
)
 
cls_id = fields.ChoiceField(
    choices=models.Classes.objects.values_list('id','title'),
    widget=widgets.Select(attrs={'class': 'form-control'})
)
 
 
obj = FooForm({'cls_id':1})
 
#多选
xx = fields.MultipleChoiceField(
    choices=models.Classes.objects.values_list('id','title'),
    widget=widgets.SelectMultiple
)
 
obj = FooForm({'cls_id':[1,2,3]}) 
View Code

1. 修复编辑老师时,不能实时更新班级列表 

方式一(推荐): 

from django.forms import Form
from django.forms import widgets
from django.forms import fields
from django.core.validators import RegexValidator

class TeacherForm(Form):
    tname = fields.CharField(min_length=2)
    xx = fields.MultipleChoiceField(
        # choices=models.Classes.objects.values_list("id","title"),
        widget=widgets.SelectMultiple
    )
    def __init__(self,*args,**kwargs):
        super(TeacherForm,self).__init__(*args,**kwargs)
        self.fields["xx"].choices =models.Classes.objects.values_list("id","title")
View Code

方式二:

from django import forms
from django.forms import fields
from django.forms import widgets
from django.forms import models as form_model
from django.core.exceptions import ValidationError
from django.core.validators import RegexValidator


class TeacherForm(Form):
    tname = fields.CharField(min_length=2)
    xx = form_model.ModelMultipleChoiceField(queryset=models.Classes.objects.all())
    # xx = form_model.ModelChoiceField(queryset=models.Classes.objects.all())


class Classes(models.Model):
    title = models.CharField(max_length=32)

    def __str__(self):
        return self.title
View Code

b. checkbox:

class TestForm(Form):
    t1 = fields.CharField(
        widget=widgets.Textarea(attrs={})
    )

    #单选框
    t2 = fields.CharField(
        widget=widgets.CheckboxInput
    )

    #复选框
    t3 = fields.MultipleChoiceField(
        choices=[(1,"篮球"),(2,"足球"),(3,"溜溜球")],
        widget=widgets.CheckboxSelectMultiple
    )


def test(request):
    obj = TestForm(initial={"t3":[2,3]})
    return render(request,"test.html",{"obj":obj})
View Code

c. radio 

class TestForm(Form):
   
    t4 = fields.MultipleChoiceField(
        choices=[(1,"篮球"),(2,"足球"),(3,"溜溜球")],
        widget=widgets.RadioSelect
    )
    t5 = fields.ChoiceField(
        choices=[(1,"篮球"),(2,"足球"),(3,"溜溜球")],
        widget=widgets.RadioSelect
    )



def test(request):
    obj = TestForm()
    return render(request,"test.html",{"obj":obj})
View Code

四. 提交方式 

1. 两种提交方式: 

提交方式:
    - Form提交(刷新,失去上次内容)
    - Ajax提交(不刷新,保留上次内容) 

a. form提交

urlpatterns = [

    url(r'^login/', views.login),
]
urls.py
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <form method="POST" action="/login/">
        {% csrf_token %}
        <p>
            用户:<input type="text" name="username"/>{{ obj.errors.username.0 }}
        </p>
        <p>
            密码:<input type="password" name="password"/>{{ obj.errors.password.0 }}
        </p>
        <input type="submit" value="提交" />{{ msg }}
    </form>
</body>
</html>
login.html
from django.shortcuts import render,HttpResponse,redirect

from django.forms import Form
from django.forms import fields
class LoginForm(Form):
    # 正则验证: 不能为空,6-18
    username = fields.CharField(
        max_length=18,
        min_length=6,
        required=True,
        error_messages={
            'required': '用户名不能为空',
            'min_length': '太短了',
            'max_length': '太长了',
        }
    )
    # 正则验证: 不能为空,16+
    password = fields.CharField(min_length=16,required=True)
    # email = fields.EmailField()
    # email = fields.GenericIPAddressField()
    # email = fields.IntegerField()


def login(request):
    if request.method == "GET":
        return render(request,'login.html')
    else:
       obj = LoginForm(request.POST)
       if obj.is_valid():
           # 用户输入格式正确
           print(obj.cleaned_data) # 字典类型
           return redirect('http://www.baidu.com')
       else:
           # 用户输入格式错误
           return render(request,'login.html',{'obj':obj})

Views.py
Views.py

b. Ajax提交

urlpatterns = [

    url(r'^ajax_login', views.ajax_login),
]
urls.py
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

    <h3>用户登录</h3>
    <form id="f1">
        {% csrf_token %}
        <p>
            <input type="text" name="user">{{ obj.errors.user.0 }}
        </p>
        <p>
            <input type="password" name="pwd">{{ obj.errors.pwd.0 }}
        </p>


        <a onclick="Ajax_sublit()">提交</a>

    </form>

    <script src="/static/jquery-3.2.1.js"></script>
    <script>
        function Ajax_sublit() {
            $(".c1").remove();
            $.ajax({
                url:"/ajax_login/",
                type:"POST",
                data:$("#f1").serialize(),
                dataType:"JSON",
                success:function (arg) {
                    console.log(arg);
                    if(arg.staus){

                    }else {
                        $.each(arg.msg,function (index,value) {
                            console.log(index,value);
                            var tag = document.createElement("span");
{#                            var tag = $("<span>");#}
                            tag.innerHTML = value[0];
{#                            tag.HTML(value[0]);#}
                            tag.className = "c1";
                            $("#f1").find('input[name="'+ index +'"]').after(tag);

                        })
                    }
                }
            })
        }
    </script>


</body>
</html>
login.html
from django.shortcuts import render,HttpResponse

# Create your views here.
from django.forms import Form,fields


class LoginForm(Form):
    user = fields.CharField(required=True)
    pwd = fields.CharField(min_length=6)



def ajax_login(request):
    import json
    ret = {"status":True,"msg":None}
    if request.method == "GET":
        return render(request,"login.html")
    else:
        obj = LoginForm(request.POST)
        if obj.is_valid():
            print(obj.cleaned_data)
        else:
            ret["status"] = False
            ret["msg"] = obj.errors

        v = json.dumps(ret)
        return HttpResponse(v)
View.py
原文地址:https://www.cnblogs.com/golangav/p/7111642.html