from和modelform的用法和介绍
一 form
1. form的作用
1. 生成HTML代码
2. 帮我们做数据有效性的校验
3. 保留上次输入内容，显示错误提示
2. form组件校验数据有效性
1. 内置的校验规则
1. require=True 该字段必填
2. max_length 该字段的最大长度
3. min_length 该字段的最小长度
2. 自定义校验规则
1. 如手机号的格式 利用内置的正则校验器
from django.core.validators import RegexValidator
validators=[RegexValidator(r'^1[356789]\d{9}$', "手机号码格式不正确")],
3. 使用钩子函数做校验
1. 局部钩子（hook）
在form类内部定义一个 clean_字段名() 方法
例子
#自定义一个局部钩子函数含有alex的关键字不能提交def clean_title(self):value=self.cleaned_data.get("title") #获取书名if "alex" in value:raise ValidationError("ALEX以备和谐")else:return value
2. 全局钩子
在form类内部定义一个 clean() 方法
4. form组合如何给html标签设置默认值
1. 每一个字段设置默认值
initial="默认值"
实例：关于使用form的例子，使用form之前可以自己写一个单独的form类，我这里一添加book为例：
1 form.py
1 from django import forms 2 from app01 import models 3 from django.core.exceptions import ValidationError #注册功能 4 from django.core.validators import RegexValidator # 检验手机号码是否正确 5 6 # 自己定义一个form类 7 class BookForm(forms.Form): 8 title=forms.CharField( 9 max_length=12, 10 min_length=2, 11 # 如果想让网页显示中文就加上label 12 label="书名", 13 initial="填写书名", 14 # 给tttle生成的input标签加上一个class类 15 widget=forms.widgets.TextInput(attrs={"class":"form-control"}) 16 ) 17 publisher_date=forms.DateField( 18 label="出版日期", 19 # widget 插件 20 widget=forms.widgets.DateInput(attrs={"type":"date","class":"form-control"}) 21 ) 22 phone=forms.CharField( 23 max_length=11, 24 validators=[RegexValidator(r'^1[356789]\d{9}$',"手机号码格式不正确")], # 限制手机号格式 25 widget = forms.widgets.TextInput(attrs={"class": "form-control"}) 26 ) 27 # 用modelchoicefield可以实时显示到页面上面当数据库增加的时候 28 publisher = forms.ModelChoiceField( 29 queryset=models.Publisher.objects.all(), 30 widget=forms.widgets.Select(attrs={"class": "form-control"}), 31 ) 32 authors=forms.ModelMultipleChoiceField( 33 queryset=models.Author.objects.all(), 34 widget=forms.widgets.SelectMultiple(attrs={"class": "form-control"}) 35 ) 36 #自定义一个局部钩子函数含有alex的关键字不能提交 37 def clean_title(self): 38 value=self.cleaned_data.get("title") #获取书名 39 if "alex" in value: 40 raise ValidationError("ALEX以备和谐") 41 else: 42 return value
2 views.py里面的配置做了一些改变
首先要导入你刚才自己定义的BookForm
from app01.forms import BookForm
def add_book(request):form_obj=BookForm()if request.method=="POST":form_obj=BookForm(request.POST)if form_obj.is_valid(): #做数据有效性校验# 因为有多对多的字段，所以需要额外处理authors=form_obj.cleaned_data.pop("authors")# 创建新书籍对象book_obj=models.Book.objects.create(**form_obj.cleaned_data)# 讲书籍对象和作者建立关联book_obj.authors.add(*authors)return redirect("/book_list/")return render(request,"add_book.html",locals())
编辑功能
def edit_book(request,pk):book_obj=models.Book.objects.filter(id=pk).first()from django.forms import model_to_dict # 导入这个模块book_dict=model_to_dict(book_obj) # 转换成字典格式book_dict["publisher_date"]=book_obj.publisher_date.strftime("%Y-%m-%d") # 时间转换成字符串格式form_obj=BookForm(book_dict)if request.method=="POST":form_obj=BookForm(request.POST) # 接受用户传来的数据if form_obj.is_valid(): # 判断数据是否正常book_obj.title=form_obj.cleaned_data.get("title")book_obj.publisher_id=form_obj.cleaned_data.get("publisher_date")book_obj.publisher_id=form_obj.cleaned_data.get("publisher")book_obj.save()book_obj.authors.set(form_obj.cleaned_data.get("authors"))return redirect("/book_list")return render(request,"edit_book.html",locals())
3 html里面也做了一些改变：（一些类的名字也都在forms里面给自动添加上了）
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>添加书籍</title> 6 <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.css" rel="stylesheet"> 7 </head> 8 <body> 9 <div class="container"> 10 <div class="row"> 11 <div class="col-md-8 col-md-offset-2"> 12 <h1>添加书籍</h1> 13 <form action="" method="post" novalidate autocomplete="off"> 14 {% for field in form_obj %} 15 <div class="form-group"> 16 <label for="{{ field.id_for_label }}">{{ field.label }}</label> 17 {{ field }} 18 <p>{{ field.errors.0 }}</p> 19 20 </div> 21 {% endfor %} 22 <input type="submit" class="btn btn-success"> 23 </form> 24 25 </div> 26 27 </div> 28 29 </div> 30 31 </body> 32 </html>
二 model form
1. 必须继承forms.ModelForm
2. class Meta：
model = "一对一关联的model类名"
fields = "__all__"
3. 实例化
1. BookModelForm(instance=book_obj)
2. BookModelForm(request.POST, instance=book_obj)
4. form_obj.save()
要想使用modelform,也必须先写个modelform
modelform例子：
1 modelform.py
from django import forms from django.core.validators import RegexValidator from django.core.exceptions import ValidationError from app01 import modelsclass BookModelForm(forms.ModelForm):class Meta:model=models.Bookfields="__all__" #model类里面所有的字段都展示# fields="title" # 指定展示某些字段# exclude=["title"] # 除了知道字段，其他字段都展示# labels可以设置在网页上面显示的文字labels={"title":"书名","publisher_date":"创建日期","phone":"手机号","publisher":"出版社","authors":"作者",}widgets={ # 设置每个字段的插件信息"title": forms.widgets.TextInput(attrs={"class": "form-control"}),"phone": forms.widgets.TextInput(attrs={"class": "form-control"}),"publisher": forms.widgets.Select(attrs={"class": "form-control"}),"authors": forms.widgets.SelectMultiple(attrs={"class": "form-control"}),}error_messages = { # 设置每个字段的报错提示信息"publisher": {"required": "必须给我选一个出版社！"},"authors":{"required":"必须选择一个作者"}}
2 views.py里面设置：
要先导入你刚才写的那个
from app01.forms import BookModelForm
添加
def add_book(request):form_obj = BookModelForm()if request.method == "POST":form_obj = BookModelForm(request.POST)if form_obj.is_valid():form_obj.save()return redirect("/book_list/")return render(request, "add_book.html", locals())
编辑
def edit_book(request, pk):book_obj = models.Book.objects.filter(id=pk).first()print("我是book_obj", book_obj)# instance实例form_obj = BookModelForm(instance=book_obj) # 实例化的form_objif request.method == "POST":# 获取用户提交过来的数据，用request.POST传过来的数据去更新book_obj这本书form_obj = BookModelForm(request.POST, instance=book_obj)if form_obj.is_valid():form_obj.save()return redirect("/book_list/")return render(request, "edit_book.html", locals())
3 html编辑和添加内容都是一样的
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>添加书籍</title> 6 <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.css" rel="stylesheet"> 7 </head> 8 <body> 9 10 <div class="container"> 11 <div class="row"> 12 <div class="col-md-8 col-md-offset-2"> 13 <h1>添加书籍</h1> 14 15 <form action="" method="post" novalidate autocomplete="off"> 16 {% csrf_token %} 17 18 {% for field in form_obj %} 19 <div class="form-group"> 20 <label for="{{ field.id_for_label }}">{{ field.label }}</label> 21 {{ field }} 22 <p>{{ field.errors.0 }}</p> 23 </div> 24 {% endfor %} 25 <input type="submit" class="btn btn-success"> 26 </form> 27 </div> 28 </div> 29 </div> 30 31 </body> 32 </html>
引用自咳~