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:
from django import forms
from django.core.exceptions import ValidationError
from app01 import modelsclass 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。
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})
app01/urls.py 文件添加以下规则:
path('add_emp/', views.add_emp)
HTML 模版:
<!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:
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 valdef 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_dataelse:raise ValidationError("请确认工资是否一致。")
views.py 文件代码:
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_datadata.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:
<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: