在Django中自定義filter并在template中的使用詳解
Django內置的filter有很多,然而我們由于業務邏輯的特殊要求,有時候仍然會不夠用,這個時候就需要我們自定義filter來實現相應的內容。接下來讓我們從自定義一個get_range(value)來產生列表的filter開始吧。
首先在你的django app的models.py的同級目錄建立一個templatetags的文件夾,并在里面新建一個init.py的空文件,這個文件確保了這個文件夾被當做一個python的包。在添加了templatetags模塊之后,我們需要重新啟動服務器才能使其有效。
polls/ __init__.py models.py templatetags/ __init__.py views.py
然后在templatetags中新建一個python文件,文件名就是以后需要加載到頁面的自定義庫的名字。在這里我們新建一個generalfilters.py文件。
polls/ __init__.py models.py templatetags/ __init__.py generalfilters.py views.py
為了讓庫生效,必須在文件里添加一個模塊級別的register變量。它是template.Library的實例,確保了標簽和過濾器的有效性。
編輯generalfilters.py,添加
from django import templateregister=template.Library()@register.filterdef get_range(value): return range(value)
上述代碼中定義了一個生成列表的函數,@register.filter表示這個函數是一個過濾器。至此我們的生成列表的過濾器就已經寫好了。接下來我們需要把這個過濾器的庫加載到模板里。
在你想要使用的模板的頂部加上{% load generalfilters %},就可以使用這個過濾器了。
{% for i in 5|get_range_bet_within %} {{i}}{% endfor %}
運行結果
補充知識:Django 自定義篩選器:重寫DateFieldListFilter
我就廢話不多說了,大家還是直接看代碼吧!
class MyDateTimeFilter(admin.filters.DateFieldListFilter): def __init__(self, *args, **kwargs): super(MyDateTimeFilter, self).__init__(*args, **kwargs) now = timezone.now() # When time zone support is enabled, convert 'now' to the user’s time # zone so Django’s definition of 'Today' matches what the user expects. if timezone.is_aware(now): now = timezone.localtime(now) filter_end_date = now.replace(hour=0, minute=0, second=0, microsecond=0) filter_start_date_for_one_week = filter_end_date - datetime.timedelta(days=7) month_with_day31 = [1,3,5,7,8,10,12] if filter_end_date.month in month_with_day31 and filter_end_date.day == 31 and filter_end_date.month != 3: if filter_end_date.month == 1:filter_start_date_for_one_month = filter_end_date.replace(year=filter_end_date.year-1, month=12) else:filter_start_date_for_one_month = filter_end_date.replace(month=filter_end_date.month-1, day=30) elif filter_end_date.month == 3 and filter_end_date.day in [29, 30, 31]: if is_leap_year(filter_end_date.year):filter_start_date_for_one_month = filter_end_date.replace(month=filter_end_date.month-1, day=29) else:filter_start_date_for_one_month = filter_end_date.replace(month=filter_end_date.month-1, day=28) else: if filter_end_date.month == 1:filter_start_date_for_one_month = filter_end_date.replace(year=filter_end_date.year-1, month=12) else:filter_start_date_for_one_month = filter_end_date.replace(month=filter_end_date.month-1)filter_start_date_for_six_month = ’’ filter_start_date_for_six_month_month = (filter_end_date.month - 6 + 12) % 12 if filter_start_date_for_six_month_month == 0: filter_start_date_for_six_month_month = 12 if filter_start_date_for_six_month_month in month_with_day31: if filter_end_date.month > 6:filter_start_date_for_six_month = filter_end_date.replace(month=filter_start_date_for_six_month_month) else:filter_start_date_for_six_month = filter_end_date.replace(year=filter_end_date.year-1, month=filter_start_date_for_six_month_month) elif filter_start_date_for_six_month_month == 2: if filter_end_date.day in [29, 30, 31]:if is_leap_year(filter_end_date.year): filter_start_date_for_six_month = filter_end_date.replace(month=filter_start_date_for_six_month_month, day=29)else: filter_start_date_for_six_month = filter_end_date.replace(month=filter_start_date_for_six_month_month, day=28) else:filter_start_date_for_six_month = filter_end_date.replace(month=filter_start_date_for_six_month_month) else: if filter_end_date.day == 31 and filter_end_date.month >6:filter_start_date_for_six_month = filter_end_date.replace(month=filter_start_date_for_six_month_month, day=30) elif filter_end_date.day == 31 and filter_end_date.month <=6:filter_start_date_for_six_month = filter_end_date.replace(year=filter_end_date.year-1, month=filter_start_date_for_six_month_month, day=30) elif filter_end_date.day <31 and filter_end_date.month >6:filter_start_date_for_six_month = filter_end_date.replace(month=filter_start_date_for_six_month_month) else:filter_start_date_for_six_month = filter_end_date.replace(year=filter_end_date.year-1, month=filter_start_date_for_six_month_month) filter_end_date = filter_end_date + datetime.timedelta(days=1) self.links = (( (’------’, {}), (’Past week’, {self.lookup_kwarg_since: str(filter_start_date_for_one_week),self.lookup_kwarg_until: str(filter_end_date), }), (’Past month’, {self.lookup_kwarg_since: str(filter_start_date_for_one_month),self.lookup_kwarg_until: str(filter_end_date), }), (’Past 6 months’, {self.lookup_kwarg_since: str(filter_start_date_for_six_month),self.lookup_kwarg_until: str(filter_end_date), }), (’All’, {}), ))
以上這篇在Django中自定義filter并在template中的使用詳解就是小編分享給大家的全部內容了,希望能給大家一個參考,也希望大家多多支持好吧啦網。
相關文章:
