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What this article shares to you is about how to rewrite admin save_model. The editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

1. Save_model rewriting of admin

Our background project is useful to the admin backend module of django. Some configuration functions can be realized through django, and there is no need to develop the management page at the front end, but some operations need to be customized, such as the QR code rule of a certain Mini Program. After admin saves the configuration, you need to call the WeChat interface to update the corresponding configuration. The interface exposed by admin only saves the data to the database. After saving the implementation, you need to overwrite the source code save_mode method of admin to call the Wechat api API, as shown below:

From django.contrib import admin

# Register your models here.from index.models import QrCode

Class QrCodeAdmin (admin.ModelAdmin):

Def save_model (self, request, obj, form, change):

Content = form.cleaned_data.get ("content") # gets the information filled in the page form. It is a dictionary type try: now = json.loads (content) except Exception as e: raise TypeError ("QR code rule configuration must be formatted by json") if change: # (if added, change is False True when modifying the data) old = self.get_object (request Obj.id) # this method can get the unsaved object old = old.content old = json.loads (old) if old! = now: # if you modify the QR code parameter # get appid pt_appid_ = AppletServer.objects.filter (qr_code=obj.id) .values_list ("app_id" Flat=True) # third-party platform appid set_pt_appid = set (pt_appid_) apps_id = MiniApp.objects.filter (AppId__in=set_pt_appid) .values_list ("app_id", flat=True) for appid in apps_id: add_qr_code (app_id=appid Json_kwargs=now) obj.save () # Save the result admin.site.register (QrCode, QrCodeAdmin) # register the model with admin

When you click Save in the following figure, admin calls the save_model method above, and comments are added to the code.

Second, customize the query set of the model model.

For example, we used to have a model Customer, and all previous queries about Customer used Customer.objects.all (). But recently we have a need to add a field to Customer whether it is the default user of Wechat. In that case, we have to add a filter condition to the original Cusomer query, so that the previously written statement code about the Customer query has to be changed in many places. But this can rewrite the management class object method to achieve the above requirements, without having to change so much code. Effects such as:

The Customer.objects.all () query is not the customer of Wechat's default user

Customer.all_objects.all () queries all customer

The code is as follows:

Class AllCustomerManager (models.Manager): # change the result set of the query def all (self): # 1. Call the all of the parent class to get all the data customers = super (). All () # 2. The books returned is a QuerySet collection, and you can continue to use all query return customers

Class CustomerManager (models.Manager): # change the result set of the query def get_queryset (self): return super (CustomerManager, self). Get_queryset (). Filter (is_default_wx=False)

Class Customer (models.Model, CustomerMixin): user = models.OneToOneField (BaseUser, on_delete=models.PROTECT, related_name= "customer", null=True) is_default_wx = models.BooleanField (verbose_name= "Wechat default user", default=True)

Class Meta: ordering = ["- id",] db_table = "customer" verbose_name = "customer"

# def _ _ str__ (self): # return self.company_name

All_objects = AllCustomerManager () # Custom a customer's management class object objects = CustomerManager () # Custom a customer's management class object above is how to rewrite the save_model of admin. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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