I. Content review
Model
- Database operations
- validate
class A(MOdel):
user =
email =
pwd =
Form
- class LoginForm(Form):
email = ()
user =
pwd =- is_valid -> regularize every field (field built-in regularity) + clean_fields -> clean(__all__) -> _post_clean
- cleand_data
- error
--------> Recommended Form <---------
ModelForm operation and validation
Model + Form ==> ModelForm. combination of model and form, so has the following functionality:
data validation
database operation
The model has fields to manipulate the database, and the form validation also has those fields, although the coupling is reduced, but the code is duplicated. If you utilize the fields in the model, is it that the fields in the form don't need to be written.
1. Model + Form (previous operation)
class UserType(): caption = (max_length=32) class UserInfo(): username = (max_length=32) email = () user_type = (to='UserType',to_field='id')
from django import forms
from import fields
class UserInfoForm():
# username = (max_length=32)<-- models
username = (max_length=32)
# email = ()<-- models
email = ()
# user_type = (to='UserType',to_field='id')<-- models
user_type = (
choices=.values_list('id','caption')
)
# The following action is to have the data updated in real time on the web page.
def __init__(self, *args, **kwargs):
super(UserInfoForm,self).__init__(*args, **kwargs)
['user_type'].choices = .values_list('id','caption')
<body>
<form action="/index/" method="POST" novalidate="novalidate">
{% csrf_token %}
{{ obj.as_p }}
<input type="submit" value="Submit">
</form>
</body>
novalidate : HTML5 input types and browser validation
Django will use HTML5 input types like url, email, and number if the form contains URLField, EmailField, and other integer fields similarly. By default, browsers may perform their own validations on these fields, which may be stricter than Django's validations. If you want to disable this behavior, set the novalidate attribute of the form tag or formulate a different field such as TextInput.
2、ModelForm basic operation
class UserInfoModelForm(): class Meta: model = # Dependencies established with models fields = "__all__"
def index(request):
if == "GET":
obj = UserInfoModelForm()
return render(request,"",{'obj':obj})
elif == "POST":
obj = UserInfoModelForm()
print(obj.is_valid()) # Here's the method, don't forget the brackets #
print(obj.cleaned_data)
print()
return render(request,"",{'obj':obj})
Customized field names
How to define the field defined on http, customize it to write in Chinese? The previous use is to write the label in the Form. model Form definition to use verbose_name
class UserInfo(): username = (max_length=32, verbose_name='User') email = (verbose_name='Mailbox') user_type = (to='UserType',to_field='id', verbose_name='Type')
If not defined in the model, implemented in the modelForm, using labels
class UserInfoModelForm():
class Meta:
model =
fields = "__all__"
labels = {
'username':'Username',
'email':'Mailbox',
}
Show specified columns
fields = "__all__" # Show all fields fields = ['username','email'] # Display the specified column exclude = ['username'] # Exclude Specified Columns
Why can I do validation in modelForm as well?
Inside the form are is_valid, cleaned_data, errors.
# Form Validation: UserInfoForm -> Form -> BaseForm( embodyis_validand other methods) # ModelForm validation: UserInfoModelForm -> ModelForm -> BaseModelForm -> BaseForm
3、ModelForm component
ModelForm
a. class Meta:
model, # Corresponding to Model
fields=None, # field
exclude=None,# Excluded fields
labels=None, # Tips
help_texts=None, # Helpful Hints
widgets=None,# Custom Plug-ins
error_messages=None, # Customized error messages (overall error messages from import NON_FIELD_ERRORS)
field_classes=None # Custom field classes (can also customize fields)
localized_fields=('birth_date',) # localization，as if：Display of data according to different time zones
As:
databases
2016-12-27 04:10:57
Configuration in Setting
TIME_ZONE = 'Asia/Shanghai'
USE_TZ = True
Then show:
2016-12-27 12:10:57
b. Validation of the implementation process
is_valid -> full_clean -> hook -> overall error
c. Dictionary field validation
def clean_field name(self): # Can throw an exception # from import ValidationError return "New value"
d. For validation
model_form_obj = XXOOModelForm() model_form_obj.is_valid() model_form_obj.errors.as_json() model_form_obj.clean() model_form_obj.cleaned_data
e. For the creation of
model_form_obj = XXOOModelForm() #### Page displayed and submitted ##### # Save many-to-many by default obj = (commit=True) # do nothing, internally define save_m2m (for saving many-to-many) obj = (commit=False) () # Save sheet information obj.save_m2m() # Save associated many-to-many information
f. For updating and initialization
obj = (id=1) model_form_obj = XXOOModelForm(,instance=obj) ...
PS: Simple initialization
model_form_obj = XXOOModelForm(initial={...})
Note: Import module names (fields, widgets) and field names are duplicated, so import with individual names.
from django import forms
from import fields as Ffields
from import widgets as Fwidgets
class UserInfoModelForm():
is_rmb = (widget=())
class Meta:
model =
fields = '__all__'
# fields = ['username','email']
# exclude = ['username']
labels = {
'username': 'Username',
'email': 'Mailbox',
}
help_texts = {
'username': '...'
}
widgets = {
'username': (attrs={'class': 'c1'})
}
error_messages = {
'__all__':{# Overall error messages
},
'email': {
'required': 'Mailbox cannot be empty',
'invalid': 'Mailbox format error...',
}
}
field_classes = { # What is the class that defines the field
# 'email': # This can only be filled with classes, with parentheses it's an object.
}
# localized_fields=('ctime',) # which fields to localize
4, ModelForm database operations
4.1 Create data save
If the data validation is ok, then save, which creates the data directly in the database.
if obj.is_valid():
() # Create data
In the following one-to-many and many-to-many relationships:
class UserType(): caption = (max_length=32) class UserGroup(): name = (max_length=32) class UserInfo(): username = (max_length=32) email = () user_type = (to='UserType',to_field='id') u2g = (UserGroup)
In that case, executing the above () will add data to both the UserInfo table and the many-to-many relationship table.
def index(request):
if == "GET":
obj = UserInfoModelForm()
return render(request,'',{'obj': obj})
elif == "POST":
obj = UserInfoModelForm()
if obj.is_valid():
() # Equivalent to the following three sentences
# instance = (False)
# ()
# obj.save_m2m()
return render(request,'',{'obj': obj})
4.2 What does save do?
save source code:
def save(self, commit=True): """""" if commit: ()# refers to the current model object self._save_m2m()# Refers to: preservation of m2m objects else: self.save_m2m = self._save_m2m return # Objects of the model class """"""
So instance = (False) operates nothing.
if obj.is_valid(): instance = (False) () # Current object table data creation obj.save_m2m() # Many-to-many table data creation # These three sentences above are completed with the above routine。Take it apart and you can customize the operation
4.3 Modification of data
To modify the table data, remember to pass in the instance information as well, otherwise it's new data, not a modification of a row of data.
Edit user information, new url method retains default data
url(r'^user_list/', views.user_list),
url(r'^edit-(\d+)/', views.user_edit),
def user_list(request):
li = ().select_related('user_type') # Only foreign keys are allowed here, not even many-to-many fields #
return render(request,'user_list.html',{'li': li})
def user_edit(request, nid):
# Get user information for the current id object
# Show user already exists data
if == "GET":
user_obj = (id=nid).first()
mf = UserInfoModelForm(instance=user_obj) # Pass in the default data
return render(request,'user_edit.html',{'mf': mf, 'nid': nid})
elif == 'POST':
# Information on data modification, to which row of the database is the modification made?
user_obj = (id=nid).first()
mf = UserInfoModelForm(,instance=user_obj) # Designate to whom changes are to be made
if mf.is_valid():
()
else:
print(.as_json())
return render(request,'user_edit.html',{'mf': mf, 'nid': nid})
user_list.html
<body>
<ul>
{% for row in li %}
<li>{{ }} - {{ row.user_type.caption }} - <a href="/edit-{{ }}/" rel="external nofollow" >compiler</a></li>
{% endfor %}
</ul>
</body>
user_edit.html
<body>
<form method="POST" action="/edit-{{ nid }}/">
{% csrf_token %}
{{ mf.as_p }}
<input type="submit" value="Submit" />
</form>
</body>
5. ModelForm hooks, extra fields
Data Validation Hooks
From the above Form and ModelForm, they both inherit from BaseForm, and is_valid is defined in BaseForm, so ModelForm can also use various hooks as well as Form
additional field
Like the checkbox on the web page, do I use submit to the database for one month without login? This just needs session and cookie settings.
class UserInfoModelForm(): is_rmb = (widget=()) # Additional fields class Meta: model = fields = '__all__'
6. Summary
1. Generate HTML tags: class Meta: ...
2. mf = xxxModelForm(instance=ModelObj) Generate Default Values
3. additional label, is_rmb = (widget=())
4. various validations is_valid() -> various hooks...
5. ()
# or instance = (False) () mf.save_m2m()
ModelForm because the model and form coupling is too close, so generally write small programs with it.
Additional knowledge:Django - rest serialization (custom serializers)
from import render
from rest_framework.views import APIView
from rest_framework.response import Response
from repository import models
from rest_framework import serializers
class MyField():
# Return data to to_respresentation
def get_attribute(self, instance):
teacher_list = ()
return teacher_list
# Formatted data
def to_representation(self, value):
ret = []
for row in value:
({'id': ,'name':})
return ret
class TestSerializer():
# get_attribute, get the value from the database
# to_representation, displaying the value in the page
# level_name = (source='get_level_display') # obj.get_level_display
# test_char= (source='') # as . across tables
x1 = ()
xx = MyField()
class Meta:
model =
fields = ['name','level_name']
def get_x1(self,obj):
pass
directly in the ModelSerializer as get_field
class CouserDetailSerializer():
course_name = (source='')
recommend_courses_list = ()
price_policy_list = ()
class Meta:
model =
fields = ['id','course_name','recommend_courses_list']
def get_recommend_courses_list(self,obj):
ret = []
course_list = obj.recommend_courses.all()
for item in course_list:
({'id':,'name':})
return ret
def get_price_policy_list(self,obj):
# All pricing strategies for the current course
# ret = []
# price_policy_list = .price_policy.all()
# return ret
# ret = []
# price_policy_list = (content_type__app_label='repository',
# content_type__model='course',
# object_id=obj.couser_id)
# return ret
return "ssss"
Above this Django ModelForm operation and validation methods is all that I have shared with you, I hope to give you a reference, and I hope you will support me more.