知识点
- 如何自定义表单
- 表单验证
简介
参考文档
实验步骤
非自定义表单
简单的Form处理方法
<h1>最原始的Form：全手工写</h1>
<form action="." method="post">
{% csrf_token %}
<label>增加诗词信息: </label>
author:<input id="author" type="text" name="author" value="{[ author ]}">
title:<input id="title" type="text" name="title" value="{[ title ]}">
<input type="submit" value="OK">
</form>
from django.shortcuts import render, HttpResponseRedirect
from .models import Poem
def add(request):
if request.method == 'POST':
form = AddForm(request.POST)
if not form.is_valid():
print('invalid')
return render(request, 'add_poem.html', {'form': AddForm()})
author = form.cleaned_data['author']
title = form.cleaned_data['title']
poem = Poem(author=author, title=title)
poem.save()
return HttpResponseRedirect('/')
else:
return render(request, 'add_poem.html', {'form': AddForm()})
简单的Form处理方法 + 表单验证
前端和后端最后都要做一次校验
<h1>最原始的Form：全手工写+前端表单验证</h1>
<form action="." method="post">
{% csrf_token %}
<label>增加诗词信息: </label>
author:<input id="author2" type="text" name="author" maxlength="10" minlength="1" value="{[ author ]}">
title:<input id="title2" type="text" name="title" value="{[ title ]}">
<input type="submit" value="OK">
</form>
from django.shortcuts import render, HttpResponseRedirect
from .models import Poem
def add(request):
if request.method == 'POST':
author = request.POST.get('author', "")
len_author = len(author)
if len_author < 1 or len_author > 10:
return render(request, 'add_poem.html')
title = request.POST.get('title', "")
poem = Poem(author=author, title=title)
poem.save()
return HttpResponseRedirect('/')
else:
return render(request, 'add_poem.html')
自定义表单
简单实现自定义表单Froms.py
自定义一个表单【Froms.py】
from django import forms
class AddForm(forms.Form):
author = forms.CharField(label="the author", min_length=1, max_length=10)
title = forms.CharField()
将表单导入视图函数输出到模板【views.py】
from django.shortcuts import render, HttpResponseRedirect
from .models import Poem
from .forms import AddForm
def add(request):
#表单验证
if request.method == 'POST':
author = request.POST.get('author', "")
len_author = len(author)
if len_author < 1 or len_author > 10:
return render(request, 'add_poem.html')
title = request.POST.get('title', "")
poem = Poem(author=author, title=title)
poem.save()
return HttpResponseRedirect('/')
else:
return render(request, 'add_poem.html', {'form': AddForm()})
前端模板的使用
可以使用as_p或者as_label
<h1>自定义From表单</h1>
<p>{{ errors }}</p>
<form action="." method="post">
{% csrf_token %}
<label>增加诗词信息: </label>
{{ form.as_table }}
<input type="submit" value="OK">
</form>
优化表单视图函数
通过自定义类来获取数据【views.py】
from django.shortcuts import render, HttpResponseRedirect
from .models import Poem
from .forms import AddForm
# 使用自定义类来获取数据
if request.method == 'POST':
form = AddForm(request.POST)
if not form.is_valid():
print('invalid')
return render(request, 'add_poem.html', {'form': AddForm()})
author = form.cleaned_data['author']
title = form.cleaned_data['title']
poem = Poem(author=author, title=title)
poem.save()
return HttpResponseRedirect('/')
else:
return render(request, 'add_poem.html', {'form': AddForm()})
通过Models来自定义表单
Models的定义【Models.py】
from django.db import models
# Create your models here.
class Poem(models.Model):
author = models.CharField(max_length=10)
title = models.CharField(max_length=10)
自定义一个继承ModelForm表单【Froms.py】
from django import forms
from .models import Poem
# 通过models来自定义表单
class AddForm(forms.ModelForm):
class Meta:
model = Poem
fields = ['author', 'title']
自定义表单的验证
通过Models.py来验证
Models的定义【Models.py】
from django.db import models
from django.core.validators import ValidationError
# 先定义一个用于验证的函数
def validate_pre(value):
print('author validate_pre')
if not value.startswith('a'):
raise ValidationError('u must start with a', code='invalid')
class Poem(models.Model):
# 在对应的字段中引用
author = models.CharField(max_length=10, validators=[validate_pre])
title = models.CharField(max_length=10)
通过Forms.py来验证
# ModelForm自定义表单 + 验证
class AddForm(forms.ModelForm):
class Meta:
model = Poem
fields = ['author', 'title']
# 仅用于测试，只能添加allen这个数据
def clean_author(self):
print('clean author')
data = self.cleaned_data['author']
if 'allen' not in data:
raise ValidationError('not has allen')
return data
# ModelForm自定义表单 + 验证
class AddForm(forms.ModelForm):
class Meta:
model = Poem
fields = ['author', 'title']
# 不允许数据重复
def clean(self):
print('clean')
author = self.cleaned_data['author']
title = self.cleaned_data['title']
object = Poem.objects.filter(author=author, title=title)
if object:
raise ValidationError('dup')
问题
这里有个顺序问题，哪个优先
froms.py > models.py > views.py
