Python之路：Django开发之Form和ModelForm组件

1、Django之Form组件

app：models.py

from django.db import models

# Create your models here.

class UserType(models.Model):
    captions = models.CharField(max_length=32)


class UserInfo(models.Model):
    username = models.CharField(verbose_name='用户名', max_length=32)
    email = models.EmailField()
    user_type = models.ForeignKey(to='UserType',to_field='id', on_delete=models.CASCADE)

app：view.py

from django.shortcuts import render
from django import forms
from django.forms import fields
from app0330 import models
# Create your views here.

class UserInfoForm(forms.Form):
    username = fields.CharField(max_length=32)
    email = fields.EmailField()
    user_type = fields.ChoiceField(
        choices = models.UserType.objects.values_list('id', 'captions')
    )

    def __init__(self, *args, **kwargs):
        super(UserInfoForm,self).__init__(*args, **kwargs)
        self.fields['user_type'].choices = models.UserType.objects.values_list('id', 'captions')

def index(request):
    if request.method == "GET":
        obj = UserInfoForm()
        return render(request, 'index.html', {'obj':obj})
    elif request.method == "POST":
        obj = UserInfoForm(request.POST)
        obj.is_valid()
        obj.cleaned_data()
        obj.errors

        # models.UserInfo.objects.create(**obj.cleaned_data)
        # models.UserInfo.objects.filter(id=1).update(**obj.cleaned_data)
        return render(request, 'index.html', {'obj': obj})

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/index/" method="POST">
        {{ obj.as_p }}
        <input type="submit" value="提交"/>
    </form>
</body>
</html>

Form验证

UserInfoForm --> Form --> BaseForm(is_valid等方法)
UserInfoModelForm --> ModelForm --> BaseModelForm --> BaseForm(is_valid等方法)

2、Django之ModelForm组件

  • 1、可以生产HTML标签：class Meta: ...
  • 2、可以带默认值，nid是urls.py中传过来的path('edit-int:nid/', views.user_edit)
    user_obj = models.UserInfo.objects.filter(id=nid).first()
    mf = UserInfoModelForm(request.POST, instance=user_obj)
  • 3、还可以加额外的form字段
    is_rmb = ffields.CharField(widget=fwidgets.CheckboxInput())

app：models.py 与Form的一致
app：view.py

from django.shortcuts import render
from django import forms
from django.forms import fields
from app0330 import models

class UserInfoModelForm(forms.ModelForm):
    class Meta:
        model = models.UserInfo
        fields = '__all__'                              # __all__ 代表全部列
        # fields = ['username', 'email', 'user_type']   # 手动写所有的列
        # exclude = ['user_type']                       # 排除谁

def index(request):
    if request.method == "GET":
        obj = UserInfoModelForm()
        return render(request, 'index.html', {'obj':obj})

    elif request.method == "POST":
        obj = UserInfoModelForm(request.POST)
        print(obj.is_valid())
        print(obj.cleaned_data)
        print(obj.errors)
        return render(request, 'index.html', {'obj': obj})

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/index/" method="POST">
        {% csrf_token %}
        {{ obj.as_p }}
        <input type="submit" value="提交"/>
    </form>
</body>
</html>

介绍一下ModelForm组件：

ModelForm
    a.  class Meta:
            model,                           # 对应Model的类
            fields=None,                     # 字段，表名
            exclude=None,                    # 排除字段，排除表名
            labels=None,                     # 提示信息，在html页面中显示的信息
            help_texts=None,                 # 帮助提示信息
            widgets=None,                    # 自定义插件
            error_messages=None,             # 自定义错误信息（整体错误信息from django.core.exceptions import NON_FIELD_ERRORS）
            field_classes=None               # 自定义字段类 （也可以自定义字段）
            localized_fields=('birth_date',) # 本地化，如：根据不同时区显示数据
            如：
                数据库中
                    2016-12-27 04:10:57
                setting中的配置
                    TIME_ZONE = 'Asia/Shanghai'
                    USE_TZ = True
                则显示：
                    2016-12-27 12:10:57
    b. 验证执行过程
        is_valid -> full_clean -> 钩子 -> 整体错误
 
    c. 字典字段验证
        def clean_字段名(self):
            # 可以抛出异常
            # from django.core.exceptions import ValidationError
            return "新值"
    d. 用于验证
        model_form_obj = XXOOModelForm()
        model_form_obj.is_valid()
        model_form_obj.errors.as_json()
        model_form_obj.clean()
        model_form_obj.cleaned_data
    e. 用于创建
        model_form_obj = XXOOModelForm(request.POST)
        #### 页面显示，并提交 #####
        # 默认保存多对多
            obj = form.save(commit=True)
        # 不做任何操作，内部定义 save_m2m（用于保存多对多）
            obj = form.save(commit=False)
            obj.save()      # 保存单表信息
            obj.save_m2m()  # 保存关联多对多信息
 
    f. 用于更新和初始化
        obj = model.tb.objects.get(id=1)
        model_form_obj = XXOOModelForm(request.POST,instance=obj)
        ...
 
        PS: 单纯初始化
            model_form_obj = XXOOModelForm(initial={...})
posted @ 2022-02-18 17:39  中國颜值的半壁江山  阅读(61)  评论(0)    收藏  举报