Django Form 组件
Django Form 组件用于对页面进行初始化，生成 HTML 标签，此外还可以对用户提交的数据进行校验（显示错误信息）。
报错信息显示顺序：
- 先显示字段属性中的错误信息，然后再显示局部钩子的错误信息。
- 若显示了字段属性的错误信息，就不会显示局部钩子的错误信息。
- 若有全局钩子，则全局钩子是等所有的数据都校验完，才开始进行校验，并且全局钩子的错误信息一定会显示。
使用 Form 组件，需要先导入 forms：
from django import forms
接下来我们在 app01 目录下创建一个 My_forms.py:
app01/My_forms.py
from django import forms
from django.core.exceptions import ValidationError
from app01 import models
class EmpForm(forms.Form):
name = forms.CharField(min_length=4, label="姓名", error_messages={"min_length": "你太短了", "required": "该字段不能为空!"})
age = forms.IntegerField(label="年龄")
salary = forms.DecimalField(label="工资")
from django.core.exceptions import ValidationError
from app01 import models
class EmpForm(forms.Form):
name = forms.CharField(min_length=4, label="姓名", error_messages={"min_length": "你太短了", "required": "该字段不能为空!"})
age = forms.IntegerField(label="年龄")
salary = forms.DecimalField(label="工资")
字段属性：
- label：输入框前面的文本信息。
- error_message：自定义显示的错误信息，属性值是字典， 其中 required 为设置不能为空时显示的错误信息的 key。
app01/views.py
from django.shortcuts import render, HttpResponse
from app01.My_Forms import EmpForm
from app01 import models
from django.core.exceptions import ValidationError
# Create your views here.
def add_emp(request):
if request.method == "GET":
form = EmpForm()
return render(request, "add_emp.html", {"form": form})
else:
form = EmpForm(request.POST)
if form.is_valid(): # 进行数据校验
# 校验成功
data = form.cleaned_data # 校验成功的值，会放在cleaned_data里。
data.pop('r_salary')
print(data)
models.Emp.objects.create(**data)
return HttpResponse(
'ok'
)
# return render(request, "add_emp.html", {"form": form})
else:
print(form.errors) # 打印错误信息
clean_errors = form.errors.get("__all__")
print(222, clean_errors)
return render(request, "add_emp.html", {"form": form, "clean_errors": clean_errors})
from app01.My_Forms import EmpForm
from app01 import models
from django.core.exceptions import ValidationError
# Create your views here.
def add_emp(request):
if request.method == "GET":
form = EmpForm()
return render(request, "add_emp.html", {"form": form})
else:
form = EmpForm(request.POST)
if form.is_valid(): # 进行数据校验
# 校验成功
data = form.cleaned_data # 校验成功的值，会放在cleaned_data里。
data.pop('r_salary')
print(data)
models.Emp.objects.create(**data)
return HttpResponse(
'ok'
)
# return render(request, "add_emp.html", {"form": form})
else:
print(form.errors) # 打印错误信息
clean_errors = form.errors.get("__all__")
print(222, clean_errors)
return render(request, "add_emp.html", {"form": form, "clean_errors": clean_errors})
app01/urls.py 文件添加以下规则：
path('add_emp/', views.add_emp)
HTML 模版：
app01/add_emp.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<h3>添加员工</h3>
{#1、自己手动写HTML页面#}
<form action="" method="post">
<p>姓名：<input type="text" name="name"></p>
<p>年龄：<input type="text" name="age"></p>
<p>工资：<input type="text" name="salary"></p>
<input type="submit">
</form>
{#2、通过form对象的as_p方法实现#}
{#<form action="" method="post" novalidate>#}
{# {% csrf_token %}#}
{# {{ form.as_p }}#}
{# <input type="submit">#}
{#</form>#}
{#3、手动获取form对象的字段#}
{#<form action="" method="post" novalidate>#}
{# {% csrf_token %}#}
{# <div>#}
{# <label for="id_{{ form.name.name }}">姓名</label>#}
{# {{ form.name }} <span>{{ form.name.errors.0 }}</span>#}
{# </div>#}
{# <div>#}
{# <label for="id_{{ form.age.name }}">年龄</label>#}
{# {{ form.age }} <span>{{ form.age.errors.0 }}</span>#}
{# </div>#}
{# <div>#}
{# <label for="id_salary">工资</label>#}
{# {{ form.salary }} <span>{{ form.salary.errors.0 }}</span>#}
{# </div>#}
{# <input type="submit">#}
{#</form>#}
{#4、用for循环展示所有字段#}
{#<form action="" method="post" novalidate>#}
{# {% csrf_token %}#}
{# {% for field in form %}#}
{# <div>#}
{# <label for="id_{{ field.name }}">{{ field.label }}</label>#}
{# {{ field }} <span>{{ field.errors.0 }}</span>#}
{# </div>#}
{# {% endfor %}#}
{# <input type="submit">#}
{#</form>#}
</body>
</html>
运行结果如下图所示：
局部钩子和全局钩子
定义 Form 类:
app01/My_forms.py
from django import forms
from django.core.exceptions import ValidationError
from app01 import models
class EmpForm(forms.Form):
name = forms.CharField(min_length=5, label="姓名", error_messages={"required": "该字段不能为空!",
"min_length": "用户名太短。"})
age = forms.IntegerField(label="年龄")
salary = forms.DecimalField(max_digits=5, decimal_places=2, label="工资")
r_salary = forms.DecimalField(max_digits=5, decimal_places=2, label="请再输入工资")
def clean_name(self): # 局部钩子
val = self.cleaned_data.get("name")
if val.isdigit():
raise ValidationError("用户名不能是纯数字")
elif models.Emp.objects.filter(name=val):
raise ValidationError("用户名已存在！")
else:
return val
def clean(self): # 全局钩子 确认两次输入的工资是否一致。
val = self.cleaned_data.get("salary")
r_val = self.cleaned_data.get("r_salary")
if val == r_val:
return self.cleaned_data
else:
raise ValidationError("请确认工资是否一致。")
from django.core.exceptions import ValidationError
from app01 import models
class EmpForm(forms.Form):
name = forms.CharField(min_length=5, label="姓名", error_messages={"required": "该字段不能为空!",
"min_length": "用户名太短。"})
age = forms.IntegerField(label="年龄")
salary = forms.DecimalField(max_digits=5, decimal_places=2, label="工资")
r_salary = forms.DecimalField(max_digits=5, decimal_places=2, label="请再输入工资")
def clean_name(self): # 局部钩子
val = self.cleaned_data.get("name")
if val.isdigit():
raise ValidationError("用户名不能是纯数字")
elif models.Emp.objects.filter(name=val):
raise ValidationError("用户名已存在！")
else:
return val
def clean(self): # 全局钩子 确认两次输入的工资是否一致。
val = self.cleaned_data.get("salary")
r_val = self.cleaned_data.get("r_salary")
if val == r_val:
return self.cleaned_data
else:
raise ValidationError("请确认工资是否一致。")
views.py 文件代码：
app01/views.py
def add_emp(request):
if request.method == "GET":
form = EmpForm() # 初始化form对象
return render(request, "add_emp.html", {"form":form})
else:
form = EmpForm(request.POST) # 将数据传给form对象
if form.is_valid(): # 进行校验
data = form.cleaned_data
data.pop("r_salary")
models.Emp.objects.create(**data)
return redirect("/index/")
else: # 校验失败
clear_errors = form.errors.get("__all__") # 获取全局钩子错误信息
return render(request, "add_emp.html", {"form": form, "clear_errors": clear_errors})
if request.method == "GET":
form = EmpForm() # 初始化form对象
return render(request, "add_emp.html", {"form":form})
else:
form = EmpForm(request.POST) # 将数据传给form对象
if form.is_valid(): # 进行校验
data = form.cleaned_data
data.pop("r_salary")
models.Emp.objects.create(**data)
return redirect("/index/")
else: # 校验失败
clear_errors = form.errors.get("__all__") # 获取全局钩子错误信息
return render(request, "add_emp.html", {"form": form, "clear_errors": clear_errors})
模板文件代码如下：
app01/add_emp.html
<form action="" method="post" novalidate>
{% csrf_token %}
<div>
<label for="id_{{ form.name.name }}">姓名</label>
{{ form.name }} <span>{{ form.name.errors.0 }}</span>
</div>
<div>
<label for="id_{{ form.age.name }}">年龄</label>
{{ form.age }} <span>{{ form.age.errors.0 }}</span>
</div>
<div>
<label for="id_salary">工资</label>
{{ form.salary }} <span>{{ form.salary.errors.0 }}{{ clear_errors.0 }}</span>
</div>
<div>
<label for="id_r_salary">请再输入工资</label>
{{ form.r_salary }} <span>{{ form.r_salary.errors.0 }}{{ clear_errors.0 }}</span>
</div>
<input type="submit">
</form>
运行结果如下图所示：
王皓
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat王皓
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat王皓
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat