在一對多關係模型中動態過濾對象

Question

我想訪問屬於特定課程的內容列表。我應該如何編寫我的觀點和網址來訪問它。我已經寫了意見和URL來取課程名單，但一些如何不能得到內容每門課程裏面

from django.contrib.auth.models import User 
from django.db import models 
import datetime 
from django.utils import timezone 
from django.template.defaultfilters import slugify 



class PostManager(models.Manager): 
    def live(self): 
     return self.model.objects.filter(published=True) 



class Course(models.Model): 
    course_name = models.CharField(max_length=200) 
    slug = models.SlugField(max_length=200, blank=True, default='') 
    pub_date = models.DateTimeField('date published') 
    author = models.ForeignKey(User, related_name="courses") 
    published_course = models.BooleanField(default=True) 
    objects = PostManager() 

    class Meta: 
     ordering = ["-pub_date", "course_name"] 

    def __unicode__(self): 
     return self.course_name 

    def was_published_recently(self): 
     now = timezone.now() 
     return now - datetime.timedelta(days=1) <= self.pub_date < now 

    was_published_recently.admin_order_field = 'pub_date' 
    was_published_recently.boolean = True 
    was_published_recently.short_description = 'Published recently ?' 

    def save(self, *args, **kwargs): 
     if not self.slug: 
      self.slug = slugify(self.course_name) 
     super(Course, self).save(*args, **kwargs) 

    @models.permalink 
    def get_absolute_url(self): 
     return ("course:detail",(), {"slug": self.slug}) 


class Content(models.Model): 
    course = models.ForeignKey(Course) 
    topic_name = models.CharField(max_length=200) 
    slug_topic_name = models.SlugField(max_length=200, blank=True, default='') 
    desc = models.TextField() 
    published = models.BooleanField(default=True) 
    objects = PostManager() 

    def __unicode__(self): 
     return self.topic_name 

    def save(self, *args, **kwargs): 
     if not self.slug_topic_name: 
      self.slug_topic_name = slugify(self.topic_name) 
     super(Content, self).save(*args, **kwargs) 

    @models.permalink 
    def get_absolute_url(self): 
     return ("content:detail",(), {"slug_topic_name": self.slug_topic_name}) 

我的課程/ views.py

from django.views.generic import ListView, DetailView 

from .models import Course, Content 


class CourseListView(ListView): 
    model = Course 

    def get_queryset(self): 
     queryset = super(CourseListView, self).get_queryset() 
     return queryset.filter(published_course=True) 

class CourseContentListView(ListView): 

    context_object_name = 'content_list' 
    queryset = Content.objects.filter(course__course_name='HTML5') 
    template_name = 'content/content_list.html' 

我的課程/ urls.py

from django.conf.urls import patterns, url 

from . import views 

urlpatterns = patterns('', 
    url(r"^$", views.CourseListView.as_view(), name="list"), 
    url(r"^(?P<course_name>[\w-]+)/$", views.CourseContentListView.as_view(), name="list"), 
) 

項目/ urls.py

from django.conf.urls import patterns, include, url 
from django.contrib import admin 


from . import views 

admin.autodiscover() 

urlpatterns = patterns('', 
    # Examples: 
    # url(r'^$', 'kodeworms.views.home', name='home'), 
    # url(r'^kodeworms/', include('kodeworms.foo.urls')), 
    url(r"^$", views.HomepageView.as_view(), name="home"), 
    url(r"^course/", include("course.urls", namespace="course")), 
    url(r"^course/content", include("course.urls", namespace="content")), 

    url(r'^admin/', include(admin.site.urls)), 
) 

項目\課程\模板\課程\ course_list.html

{% extends "_layouts/base.html" %} 
{% load url from future %} 

{% block page_title %}Course List | {% endblock %} 

{% block page_content %} 
<h2>Course Grid</h2> 

<ul> 
    {% for course in course_list %} 
    <li><a href="{% url 'content:list' %}">{{ course.course_name }}</a></li> 
    {% empty %} 
    <li>Sorry, no courses yet. Check back soon! </li> 
    {% endfor %} 
    <p><a href="{% url 'home' %}">&larr; Home</a></p> 
</ul> 
{% endblock %} 

項目\課程\模板\內容\ content_list.html

{% extends "_layouts/base.html" %} 

{% block page_title %}{{ course.course_name }} | {% endblock %} 


{% block page_content %} 
<h2>{{ course.course_name }}</h2> 
{{ course.content|linebreaks }} 

<ul> 
    {% for content in object_list %} 
    <li>{{ content.topic_name }}</li> 
    {% empty %} 
    <li>Sorry, no content yet. Check back soon! </li> 
    {% endfor %} 
</ul> 

<p><a href="{% url 'course:list' %}">&larr; Course List</a></p> 
{% endblock %} 

在上面的代碼中，我有硬編碼課程名稱及其內容。我想爲任何任意的過程動態獲取它。另外我的pk = 1給出錯誤，pk = 8/9/10有值。可有人請幫助

Answer 1

好吧，這是我的第一個Web項目和偏離輪詢後的第一個Django項目。所以這個soln。是爲那些像我一樣的新手/初學者進入編程/網絡開發的世界。

我的pk從pk = 8開始，所以我不知道如何訪問內容列表。但隨後用一些Django文檔閱讀和從這個Link得到的答案，我能夠找出問題並按照我的方式通過它。無論如何，這裏的修改代碼是

views.py - >早些時候，課程被硬編碼以訪問內容列表，我也試圖用主鍵動態訪問內容（我不成功）。所以現在我試圖用slu access訪問它，並取得了成功。

class CourseContentListView(ListView): 

    template_name = 'course/content_list.html' 

    def get_queryset(self): 
     self.course = get_object_or_404(Course, slug=self.kwargs['slug']) 
     return Content.objects.filter(course=self.course, published=True) 

我也看了一些更多關於Django模板從官方的文檔，並找出正確的方式來命名和訪問的URL，並更改了course_list.html訪問內容列表

course_list.html

<ul> 
    {% for course in course_list %} 
    <li><a href="{% url 'course:content_list' course.slug %}">{{ course.course_name }}</a></li> 
    {% empty %} 
    <li>Sorry, no courses yet. Check back soon! </li> 
    {% endfor %} 
    <p><a href="{% url 'home' %}">&larr; Home</a></p> 

</ul> 

更改urls.py正確指向相應的URL

我urls.py

urlpatterns = patterns('', 
    url(r"^$", views.CourseListView.as_view(), name="list"), 
    url(r"^(?P<slug>[\w-]+)/$", views.CourseContentListView.as_view(), name="content_list"), 
) 

我還在學習上面的代碼中可能會出現錯誤，或者更好/優雅的方式來做到這一點。但是，再次，這個代碼爲我工作。

Answer 2

a = Course.objects.get(pk=1) 
# List of contents for this course 
course_contents = a.content_set.all() 

Answer 3

您應該將CourseContentListView更改爲：

class CourseContentListView(ListView): 

    model = Content 
    context_object_name = 'content_list' 
    template_name = 'content/content_list.html' 

    def get_queryset(self): 
     queryset = super(CourseContentListView, self).get_queryset() 
     course_name = self.kwargs.get('course_name') 
     course = Course.objects.get(course_name=course_name) 
     queryset = queryset.filter(course=course) 
     return queryset