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.exceptionsimport 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.exceptionsimport 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.shortcutsimport render, HttpResponse
from app01.My_Formsimport EmpForm
from app01 import models
from django.core.exceptionsimport 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_Formsimport EmpForm
from app01 import models
from django.core.exceptionsimport 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
<!DOCTYPEhtml><htmllang="en"><head><metacharset="UTF-8"><title></title></head><body><h3>添加员工</h3>
{#1、自己手动写HTML页面#}
<formaction=""method="post"><p>姓名：<inputtype="text"name="name"></p><p>年龄：<inputtype="text"name="age"></p><p>工资：<inputtype="text"name="salary"></p><inputtype="submit"></form>
{#2、通过form对象的as_p方法实现#}
{#<formaction=""method="post"novalidate>#}
{# {% csrf_token %}#}
{# {{ form.as_p }}#}
{# <inputtype="submit">#}
{#</form>#}
{#3、手动获取form对象的字段#}
{#<formaction=""method="post"novalidate>#}
{# {% csrf_token %}#}
{# <div>#}
{# <labelfor="id_{{ form.name.name }}">姓名</label>#}
{# {{ form.name }} <span>{{ form.name.errors.0 }}</span>#}
{# </div>#}
{# <div>#}
{# <labelfor="id_{{ form.age.name }}">年龄</label>#}
{# {{ form.age }} <span>{{ form.age.errors.0 }}</span>#}
{# </div>#}
{# <div>#}
{# <labelfor="id_salary">工资</label>#}
{# {{ form.salary }} <span>{{ form.salary.errors.0 }}</span>#}
{# </div>#}
{# <inputtype="submit">#}
{#</form>#}
{#4、用for循环展示所有字段#}
{#<formaction=""method="post"novalidate>#}
{# {% csrf_token %}#}
{# {% for field in form %}#}
{# <div>#}
{# <labelfor="id_{{ field.name }}">{{ field.label }}</label>#}
{# {{ field }} <span>{{ field.errors.0 }}</span>#}
{# </div>#}
{# {% endfor %}#}
{# <inputtype="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.exceptionsimport 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:
returnself.cleaned_data
else:
raise ValidationError("请确认工资是否一致。")
from django.core.exceptionsimport 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:
returnself.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
<formaction=""method="post"novalidate>
{% csrf_token %}
<div><labelfor="id_{{ form.name.name }}">姓名</label>
{{ form.name }} <span>{{ form.name.errors.0 }}</span></div><div><labelfor="id_{{ form.age.name }}">年龄</label>
{{ form.age }} <span>{{ form.age.errors.0 }}</span></div><div><labelfor="id_salary">工资</label>
{{ form.salary }} <span>{{ form.salary.errors.0 }}{{ clear_errors.0 }}</span></div><div><labelfor="id_r_salary">请再输入工资</label>
{{ form.r_salary }} <span>{{ form.r_salary.errors.0 }}{{ clear_errors.0 }}</span></div><inputtype="submit"></form>
运行结果如下图所示：
