[英]Django-Tables2 add extra columns from dictionary
抱歉,如果您之前曾提出過此問題,但我找不到特定的用例回答。
我有一個顯示基本產品信息的表。 產品詳細信息(例如價格,銷售數量和銷售商數量)會定期進行抓取,並存儲在單獨的數據庫表中。 現在,我想使用tables2在前端的一個表中同時顯示基本產品信息和詳細信息。 為此,我在產品模型中編寫了一個函數,以獲取最新的詳細信息並將其作為字典返回,從而可以使用單個Accessor調用。
# models.py
class Product(models.Model):
created_at = models.DateTimeField(auto_now_add=True)
name = models.CharField(max_length=256)
brand = models.ForeignKey(Brand)
category = models.CharField(max_length=128, choices=CATEGORY_CHOICES)
def __unicode__(self):
return self.name
def currentState(self):
currentDetailState = ProductDetailsState.objects.filter(
product=self
).latest('created_at')
# return current details as a dictionary
return {
price: currentDetailState.price,
num_sellers: currentDetailState.num_sellers,
num_sales: currentDetailState.num_sales
}
class ProductDetailsState(models.Model):
product = models.ForeignKey(Product)
created_at = models.DateTimeField(auto_now_add=True)
price = models.DecimalField(max_digits=6, decimal_places=2, null=True)
num_sellers = models.IntegerField(null=True)
num_sales = models.IntegerField(null=True)
def __unicode__(self):
return self.created_at
# tables.py
class ProductTable(tables.Table):
productBrand = tables.Column(
accessor=Accessor('brand.name'),
verbose_name='Brand'
)
currentRank = tables.Column(
accessor=Accessor('currentRank')
)
class Meta:
model = Product
...
現在如何使用此返回的字典並將其拆分為“產品”表中的列? 除了我的使用方式,還有其他使用訪問器的方法嗎?
您可以使用Accessor
遍歷dict,因此應執行以下操作:
class ProductTable(tables.Table):
# brand is the name of the model field, if you use that as the column name,
# and you have the __unicode__ you have now, the __unicode__ will get called,
# so you can get away with jus this:
brand = tables.Column(verbose_name='Brand')
currentRank = tables.Column()
# ordering on the value of a dict key is not possible, so better to disable it.
price = tables.Column(accessor=tables.A('currentState.price'), orderable=False)
num_sellers = tables.Column(accessor=tables.A('currentState.num_sellers'), orderable=False)
num_sales = tables.Column(accessor=tables.A('currentState.num_sales'), orderable=False)
class Meta:
model = Product
雖然這可行,但排序也很不錯。 為此,您的'currentState'方法有點麻煩,您應該更改傳遞給表的QuerySet。 此視圖顯示了它如何工作:
from django.db.models import F, Max
from django.shortcuts import render
from django_tables2 import RequestConfig
from .models import Product, ProductDetailsState
from .tables import ProductTable
def table(request):
# first, we make a list of the post recent ProductDetailState instances
# for each Product.
# This assumes the id's increase with the values of created_at,
# which probably is a fair assumption in most cases.
# If not, this query should be altered a bit.
current_state_ids = Product.objects.annotate(current_id=Max('productdetailsstate__id')) \
.values_list('current_id', flat=True)
data = Product.objects.filter(productdetailsstate__pk__in=current_state_ids)
# add annotations to make the table definition cleaner.
data = data.annotate(
price=F('productdetailsstate__price'),
num_sellers=F('productdetailsstate__num_sellers'),
num_sales=F('productdetailsstate__num_sales')
)
table = ProductTable(data)
RequestConfig(request).configure(table)
return render(request, 'table.html', {'table': table})
使用上面創建的注釋可以簡化表的定義:
class ProductTable(tables.Table):
brand = tables.Column(verbose_name='Brand')
currentRank = tables.Column()
price = tables.Column()
num_sellers = tables.Column()
num_sales = tables.Column()
class Meta:
model = Product
您可以在github上找到完整的django項目
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