python測試開發django-106.form表單中區域性鉤子(clean_)和全域性鉤子校驗
阿新 • • 發佈:2021-07-06
前言
在實際開發中,不僅僅是對輸入框字元的格式校驗,比如註冊功能,註冊賬號還得校驗資料庫是否已經有賬號被註冊過了。
有些場景不僅僅是對單個輸入框的字元校驗,比如修改密碼的時候,會涉及2個輸入框的資料格式校驗,像這些複雜的場景校驗需用到校驗鉤子來實現。
校驗form表單資料合法性,is_valid()方法呼叫順序:
- 1.欄位規則校驗,字元長度,是否必填等基本校驗
- 2.validators校驗(RegexValidator校驗器或自定義校驗函式)
- 3.區域性鉤子(類中定義的以clean_欄位名命名的函式,校驗正常必須返回該欄位的值self.cleaned_data.get('name'))
- 4.全域性鉤子(類中定義的函式名clean,校驗正常必須返回該物件的校驗結果值return self.cleaned_data)
- 5.每一步通過校驗單結果都以字典形式儲存在類物件的cleaned_data屬性中
註冊示例
登錄檔單RegisterForm
from django import forms from django.core.exceptions import ValidationError # 作者-上海悠悠 QQ交流群:717225969 # blog地址 https://www.cnblogs.com/yoyoketang/ class RegisterForm(forms.Form): """登錄檔單""" username = forms.CharField(label="使用者名稱", required=True, min_length=3, max_length=20, error_messages={'required': '不能為空', }) password = forms.CharField(max_length=16, min_length=6, required=True, label="密碼", widget=forms.PasswordInput, error_messages={ 'required': '密碼不能為空', 'min_length': '密碼不能少於6位字元', 'max_length': '密碼不能大於16位字元', }) email = forms.EmailField(required=False, error_messages={'invalid': '郵箱引數不合法'})
註冊檢視
from django.shortcuts import render from django.contrib.auth.models import User # 作者-上海悠悠 QQ交流群:717225969 # blog地址 https://www.cnblogs.com/yoyoketang/ def registerView(request): """註冊檢視""" if request.method == "GET": form_obj = RegisterForm() return render(request, "register_form.html", locals()) if request.method == "POST": form_obj = RegisterForm(request.POST) if form_obj.is_valid(): username = form_obj.cleaned_data.get("username") password = form_obj.cleaned_data.get("password") email = form_obj.cleaned_data.get("email") try: user = User.objects.create_user(username=username, password=password, email=email) user.save() error_msg = "註冊成功!" except Exception as msg: error_msg = "註冊賬號異常" print("註冊賬號異常:", msg) return render(request, "register_form.html", locals())
註冊模板
<form action="" method="POST" id="login-form" style="text-align:center;">
{% csrf_token %}
{% for field in form_obj %}
<p>
{{ field.label_tag }}
{{ field }}
{{ field.errors }}
</p>
{% endfor %}
<p>
{{ error_msg }}
</p>
<p>
<input type="submit" value="立即註冊" >
</p>
</form>
當註冊一個已存在的賬號test,會報註冊賬號異常: (1062, "Duplicate entry 'test' for key 'username'")
因為資料庫已經存在賬號test, 寫入資料庫時會報這個錯:Duplicate entry
區域性鉤子
在Form類裡面定義區域性鉤子,校驗資料庫,格式 clean_校驗欄位(self):
from django import forms
from django.core.exceptions import ValidationError
# 作者-上海悠悠 QQ交流群:717225969
# blog地址 https://www.cnblogs.com/yoyoketang/
class RegisterForm(forms.Form):
"""登錄檔單"""
username = forms.CharField(label="使用者名稱",
required=True,
min_length=3,
max_length=20,
error_messages={'required': '不能為空',
})
password = forms.CharField(max_length=16,
min_length=6,
required=True,
label="密碼",
widget=forms.PasswordInput,
error_messages={
'required': '密碼不能為空',
'min_length': '密碼不能少於6位字元',
'max_length': '密碼不能大於16位字元',
})
email = forms.EmailField(required=False,
error_messages={'invalid': '郵箱引數不合法'})
# 區域性鉤子
def clean_username(self):
"""判斷資料庫是否已存在"""
val = self.cleaned_data.get('username') # 獲取username欄位值
user = User.objects.filter(username=val) # 在資料庫中判斷是否存在使用者名稱
if not user:
return val # 如果通過校驗,那麼把值直接原封不動返回即可
else:
raise ValidationError('使用者已經註冊')
重複註冊的時候,就會提示使用者已被註冊
全域性鉤子
在forms.py裡面的BaseForm類可以看到clean方法,此方法是在每個Field欄位校驗之後觸發,校驗失敗錯誤資訊儲存到 errors {'all':[e,]}。
校驗成功返回self.cleaned_data
def clean(self):
"""
Hook for doing any extra form-wide cleaning after Field.clean() has been
called on every field. Any ValidationError raised by this method will
not be associated with a particular field; it will have a special-case
association with the field named '__all__'.
"""
return self.cleaned_data
於是可以重寫clean()方法,校驗輸入的2次密碼是不是一致
# 作者-上海悠悠 QQ交流群:717225969
# blog地址 https://www.cnblogs.com/yoyoketang/
class RegisterForm(forms.Form):
"""登錄檔單"""
......
# 全域性鉤子
def clean(self):
"""在通過基礎驗證的乾淨資料中get獲取欄位"""
pwd1 = self.cleaned_data.get('password')
pwd2 = self.cleaned_data.get('password2')
if pwd1 and pwd2: # 這裡判斷2個欄位都是經驗通過
if pwd1 == pwd2:
# 資料沒問題,那麼原封不動返回即可
return self.cleaned_data
else:
# 錯誤資訊儲存到 errors {'__all__':[e,]}
raise ValidationError('兩次密碼輸入不同')
else:
return self.cleaned_data
在檢視函式中可以拿到全域性鉤子錯誤資訊:form_obj.errors.get('all')[0]
# 作者-上海悠悠 QQ交流群:717225969
# blog地址 https://www.cnblogs.com/yoyoketang/
def registerView(request):
"""註冊檢視"""
if request.method == "GET":
form_obj = RegisterForm()
return render(request, "register_form.html", locals())
if request.method == "POST":
form_obj = RegisterForm(request.POST)
if form_obj.is_valid():
username = form_obj.cleaned_data.get("username")
password = form_obj.cleaned_data.get("password")
email = form_obj.cleaned_data.get("email")
try:
user = User.objects.create_user(username=username,
password=password,
email=email)
user.save()
error_msg = "註冊成功!"
except Exception as msg:
error_msg = "註冊賬號異常"
print("註冊賬號異常:", msg)
else:
# 全域性鉤子自定義錯誤提示獲取
print(form_obj.errors.get('__all__')[0])
error_msg = form_obj.errors.get('__all__')[0]
return render(request, "register_form.html", locals())
兩次密碼輸入不一樣後,在頁面上的效果