django上个月查看，上个月的url

Question

我按照上个月视图 (https://docs.djangoproject.com/en/1.9/ref/class-based-views/generic-date-based/) 上的说明进行操作，但它并没有完全显示上个月的网址。

在我的索引页面上，我以特定格式显示当前事件，然后我在顶部有即将到来的和上一个的链接，前一个转到不同的模板，我试图加载前一个月的视图。

如您所见，错误在于网址，我不太确定如何正确获取网址

urls.py

from django.conf.urls import url
from . import views

from maintenance.views import EventMonthArchiveView


app_name = 'maintenance'
urlpatterns = [
    url(r'^$', views.index, name='index'),
    url(r'^previous/(?P<year>[0-9]{4})/(?P<month>[0-9]+)/$',
        EventMonthArchiveView.as_view(month_format='%m'),
        name="previous"),
    url(r'^upcoming$', views.upcoming, name='upcoming'),

views.py

from django.views.generic.list import ListView
from django.shortcuts import get_object_or_404, render, render_to_response
from django.http import HttpResponse
from datetime import date, datetime, timedelta, time
from django.views.generic.dates import MonthArchiveView

from .models import Maintenance
from .models import MaintenanceType
from .models import ServiceType

# Create your views here.
def index(request):
    today = date.today()
    ObjMaintenance = Maintenance.objects.filter(StartTime__gt=today)

    return render(request, 'maintenance/index.html', {'Maintenance': ObjMaintenance,})

class EventMonthArchiveView(MonthArchiveView):
    queryset = Maintenance.objects.all()
    date_field = "StartTime"
    allow_future = False

index.html

{% extends 'home/base.html' %}
{% block content %}

    <h2>IT Maintenance Schedule</h2>
        <div id="page-content-header">
            <div class="float-left">
                <a href="{% url 'maintenance:previous|date:"F Y"' %}"><< Previous Maintenance</a>
            </div>
            <div class="float-middle">
                <a href="{% url 'maintenance:index' %}">Maintenance Today</a>
            </div>
            <div class="float-right">
                <a href="{% url 'maintenance:upcoming' %}">Upcoming Maintenance >></a>
            </div>
        </div>
        <div class='clear'>&nbsp;</div>
        <div id='content-body'>
            {% for event in Maintenance %}
            <p>
                {{ event.Title }}
            </p>
            {% empty %}
            <p>There is no maintenance scheulded for today.</p>
            {% endfor%}
        </div>
    {% endblock %}

错误

u'previous|date' is not a registered namespace inside 'maintenance'
Request Method: GET
Request URL:    http://it.wrenkitchens.com/maintenance/
Django Version: 1.9.6
Exception Type: NoReverseMatch
Exception Value:    
u'previous|date' is not a registered namespace inside 'maintenance'

Answer 1

首先，考虑如何在特定月份（例如 2016 年 4 月）使用 url 标签：

{% url 'maintenance:previous' '2016' '04' %}

如果你想让这个动态，那么你需要一个包含上个月的上下文变量。如果您使用 [MonthArchiveView][1], then Django includesprevious_monthin the template context for you. This is a Python date representing the first day of the previous month. You then use thedate` 过滤器将该日期时间转换为年份和月份字符串。

{% url 'maintenance:previous' previous_month|date:"Y" previous_month|date:"m" %}

请注意，我使用的是“m”，而不是“F”，因为您在网址中使用的是“04”，而不是“April”。

最后，如果您想在索引视图中使用此链接，您需要自己将previous_month 传递给模板上下文。您可以通过获取当月的第一天，然后减去一天来获得上个月的最后一天。因为你只需要

from datetime import date, timedelta

def index(request):
    today = date.today()
    previous_month = (today.replace(day=1) - timedelta(1)).replace(day=1)
    ObjMaintenance = Maintenance.objects.filter(StartTime__gt=today)

    return render(request, 'maintenance/index.html', {
        'Maintenance': ObjMaintenance,
        'previous_month': previous_month,
    })