Python之路73-Django ModelForm

ModelForm
    a.  class Meta:
            model,                           # 对应Model的
            fields=None,                     # 字段
            exclude=None,                    # 排除字段
            labels=None,                     # 提示信息
            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={...})

views.py

from django.shortcuts import render
from django import forms
from django.forms import fields as Ffields
from django.forms import widgets as Fwidgets
from app01 import models
# Create your views here.

class UserInfoModelForm(forms.ModelForm):
    
    is_rmb = Ffields.CharField(
    widget=Fwidgets.CheckboxInput()
    )
    
    class Meta:
        model = models.UserInfo     # 去哪个类中获取字段
        fields = "__all__"
        # fields = ["username", "email", ]
        # exclude = ["username", ]
        labels = {"username": "用户名",
                  "email": "邮箱"}
        help_texts = {
            "username": "..."
        }
        widgets = {
            "username": Fwidgets.Textarea(attrs={"class": "c1"})
        }
        error_messages = {
            "__all__": {

            },
            "email": {
                "required": "邮箱不能为空",
                "invalid": "邮箱格式错误"
            }
        },
        # fields_classes = {
        #     "email": Ffields.URLField
        # },
        # localized_fields=()

class UserInfoForm(forms.Form):
    username = Ffields.CharField()
    email = Ffields.EmailField()
    user_type = Ffields.ChoiceField(
        choices=models.UserType.objects.values_list("id", "caption")
    )

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

def index(request):
    if request.method == "GET":
        obj = UserInfoModelForm()
        return render(request, "index.html", {"obj": obj})
    elif request.method == "POST":
        obj = UserInfoModelForm(request.POST)
        if obj.is_valid():
            obj.save()
        # models.UserInfo.objects.create(**obj.cleaned_data)
        # models.UserInfo.objects.filter(id=1).update(**obj.cleaned_data)
        return render(request, "index.html", {"obj": obj})

def user_list(request):
    li = models.UserInfo.objects.all().select_related("user_type")
    return render(request, "user_list.html", {"li": li})

def user_edit(request, nid):
    # 获取当前ID对象的用户信息
    # 显示用户已经存在的数据
    if request.method == "GET":
        user_obj = models.UserInfo.objects.filter(id=nid).first()
        mf = UserInfoModelForm(instance=user_obj)
        return render(request, "user_edit.html", {"mf": mf, "nid": nid})
    elif request.method == "POST":
        user_obj = models.UserInfo.objects.filter(id=nid).first()
        mf = UserInfoModelForm(request.POST, instance=user_obj)
        if mf.is_valid():
            mf.save()
        else:
            print(mf.errors.as_json())
        return render(request, "user_edit.html", {"mf": mf, "nid": nid})

models.py

from django.db import models

# Create your models here.

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

class UserGroup(models.Model):
    name = models.CharField(max_length=32)

class UserInfo(models.Model):
    username = models.CharField(max_length=32)
    email = models.EmailField()
    user_type = models.ForeignKey(to="UserType", to_field="id")
    u2g = models.ManyToManyField(UserGroup)

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>

user_list.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <ul>
        {% for row in li %}
            <li>{{ row.username }} - {{ row.user_type.caption }} - <a href="/edit-{{ row.id }}/">编辑</a></li>
        {% endfor %}
    </ul>
</body>
</html>

user_edit.html

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

1. 生成HTML标签：class Meta
2. mf = xxxModelForm(instance=ModelObj)
3. 额外的标签， is_rmb = Ffields.CharField(widget=Fwidgets.CheckboxInput())
4. 各种验证 is_valid() -> 各种钩子
5. mf.save()

   # 或

   instance = mf.save(False)

   instance.save()

   mf.save_m2m()