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.htm", {"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.htm", {"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.htm", {"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.htm", {"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.htm", {"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.htm", {"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.htm
<!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.htm", {"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.htm", {"form": form, "clear_errors": clear_errors})
if request.method == "GET":
form = EmpForm() # 初始化form对象
return render(request, "add_emp.htm", {"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.htm", {"form": form, "clear_errors": clear_errors})
模板文件代码如下：
app01/add_emp.htm
<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：
