Skip to main content

联合馈送框架

Django提供了一个高级的联合馈送生成框架,使创建 RSSAtom 饲料变得容易。

要创建任何联合供稿,所需要做的就是编写一个简短的Python类。您可以根据需要创建任意数量的Feed。

Django还提供了一个较低级别的feed生成API。如果您想在Web上下文之外或以其他较低级别的方式生成Feed,请使用此选项。

高级框架

概述

高级馈源生成框架由 Feed 类提供。要创建Feed,请编写 Feed 类并指向其在 URLconf 中的实例。

Feed

Feed 类是表示联合供稿的Python类。馈送可以是简单的(例如,“站点新闻”馈送或显示博客的最新条目的基本馈送)或更复杂(例如,显示特定类别中的所有博客条目的馈送,其中类别是可变的)。

Feed类的子类 django.contrib.syndication.views.Feed。他们可以在你的代码库中的任何地方。

Feed 类的实例是可以在您的 URLconf 中使用的视图。

一个简单的例子

这个简单的例子,从假设的警察拍卖新闻网站,描述了最新的五个新闻项目的饲料:

from django.contrib.syndication.views import Feed
from django.urls import reverse
from policebeat.models import NewsItem

class LatestEntriesFeed(Feed):
    title = "Police beat site news"
    link = "/sitenews/"
    description = "Updates on changes and additions to police beat central."

    def items(self):
        return NewsItem.objects.order_by('-pub_date')[:5]

    def item_title(self, item):
        return item.title

    def item_description(self, item):
        return item.description

    # item_link is only needed if NewsItem has no get_absolute_url method.
    def item_link(self, item):
        return reverse('news-item', args=[item.pk])

要将URL连接到此Feed,请在您的 URLconf 中放入Feed对象的实例。例如:

from django.conf.urls import url
from myproject.feeds import LatestEntriesFeed

urlpatterns = [
    # ...
    url(r'^latest/feed/$', LatestEntriesFeed()),
    # ...
]

注意:

  • Feed类将 django.contrib.syndication.views.Feed 子类化。

  • titlelinkdescription 分别对应于标准RSS <title><link><description> 元件。

  • 简单来说,items() 是一种方法,它返回应该作为 <item> 元素包含在Feed中的对象的列表。虽然此示例使用Django的 对象关系映射器 返回 NewsItem 对象,但 items() 不必返回模型实例。虽然你通过使用Django模型获得了一些功能“免费”,items() 可以返回你想要的任何类型的对象。

  • 如果您要创建Atom订阅源,而不是RSS订阅源,请设置 subtitle 属性,而不是 description 属性。参见 Publishing Atom and RSS feeds in tandem,后面的例子。

有一件事要做。在RSS源中,每个 <item> 具有 <title><link><description>。我们需要告诉框架什么数据放入这些元素。

  • 对于 <title><description> 的内容,Django尝试在 Feed 类上调用方法 item_title()item_description()。它们被传递单个参数 item,它是对象本身。这些是可选的;默认情况下,对象的unicode表示形式用于两者。

    如果要对标题或描述进行任何特殊格式设置,可以改用 Django模板。它们的路径可以用 Feed 类的 title_templatedescription_template 属性指定。为每个项呈现模板,并传递两个模板上下文变量:

    请参阅下面的使用描述模板的 a complex example

    Feed.get_context_data(**kwargs)

    如果您需要提供超过前面提到的两个变量,还有一种方法可以将附加信息传递到标题和描述模板。您可以在 Feed 子类中提供 get_context_data 方法的实现。例如:

    from mysite.models import Article
    from django.contrib.syndication.views import Feed
    
    class ArticlesFeed(Feed):
        title = "My articles"
        description_template = "feeds/articles.html"
    
        def items(self):
            return Article.objects.order_by('-pub_date')[:5]
    
        def get_context_data(self, **kwargs):
            context = super(ArticlesFeed, self).get_context_data(**kwargs)
            context['foo'] = 'bar'
            return context
    

    和模板:

    Something about {{ foo }}: {{ obj.description }}
    

    此方法将由 items() 返回的列表中的每个项目调用一次,并使用以下关键字参数:

    • item:当前项。出于向后兼容性的原因,此上下文变量的名称为 {{ obj }}

    • objget_object() 返回的对象。默认情况下,这不暴露给模板,以避免与 {{ obj }} (见上文)混淆,但您可以在您的 get_context_data() 实现中使用它。

    • site:如上所述的当前位点。

    • request:当前请求。

    get_context_data() 的行为模仿 通用视图 的行为 - 你应该调用 super() 从父类检索上下文数据,添加您的数据并返回修改的字典。

  • 要指定 <link> 的内容,您有两个选项。对于 items() 中的每个项目,Django首先尝试调用 Feed 类上的 item_link() 方法。以类似的方式对标题和描述,它传递一个单一参数,item。如果该方法不存在,Django尝试对该对象执行 get_absolute_url() 方法。 get_absolute_url()item_link() 都应将项目的URL作为普通的Python字符串返回。与 get_absolute_url() 一样,item_link() 的结果将直接包含在URL中,因此您负责在方法本身内执行所有必要的URL引用和转换为ASCII。

一个复杂的例子

该框架还通过参数支持更复杂的feed。

例如,网站可以为城市中的每个警察节拍提供最近犯罪的RSS源。为每个警察打败创建一个单独的 Feed 类是愚蠢的;这将违反 DRY原理 并且将数据耦合到编程逻辑。相反,联合框架允许您访问从 URLconf 传递的参数,以便Feed可以根据Feed的网址中的信息输出项目。

警察击败饲料可以通过这样的URL访问:

  • /beats/613/rss/ - 返回最近的犯规,第613节。

  • /beats/1424/rss/ - 返回1424年最近的犯罪。

这些可以与 URLconf 线匹配,例如:

url(r'^beats/(?P<beat_id>[0-9]+)/rss/$', BeatFeed()),

与视图一样,URL中的参数与请求对象一起传递到 get_object() 方法。

以下是这些特定于节拍的Feed的代码:

from django.contrib.syndication.views import Feed

class BeatFeed(Feed):
    description_template = 'feeds/beat_description.html'

    def get_object(self, request, beat_id):
        return Beat.objects.get(pk=beat_id)

    def title(self, obj):
        return "Police beat central: Crimes for beat %s" % obj.beat

    def link(self, obj):
        return obj.get_absolute_url()

    def description(self, obj):
        return "Crimes recently reported in police beat %s" % obj.beat

    def items(self, obj):
        return Crime.objects.filter(beat=obj).order_by('-crime_date')[:30]

为了生成饲料的 <title><link><description>,Django使用 title()link()description() 方法。在前面的例子中,它们是简单的字符串类属性,但是这个例子说明它们可以是字符串 or 方法。对于 titlelinkdescription 中的每一个,Django遵循此算法:

  • 首先,它尝试调用一个方法,传递 obj 参数,其中 objget_object() 返回的对象。

  • 如果没有,它试图调用没有参数的方法。

  • 如果没有,它使用类属性。

还要注意,items() 也遵循相同的算法 - 首先,它尝试 items(obj),然后 items(),然后最终 items 类属性(它应该是一个列表)。

我们正在使用模板作为项目描述。它可以很简单:

{{ obj.description }}

但是,您可以根据需要自由添加格式。

下面的 ExampleFeed 类提供了关于 Feed 类的方法和属性的完整文档。

指定Feed的类型

默认情况下,此框架中生成的Feed使用RSS 2.0。

要改变它,添加一个 feed_type 属性到你的 Feed 类,像这样:

from django.utils.feedgenerator import Atom1Feed

class MyFeed(Feed):
    feed_type = Atom1Feed

请注意,您将 feed_type 设置为类对象,而不是实例。

目前可用的Feed类型包括:

附件

要指定机箱(例如用于创建播客馈送的机箱),请使用 item_enclosures 挂钩,或者,如果每个项目只有一个机箱,则使用 item_enclosure_urlitem_enclosure_lengthitem_enclosure_mime_type 挂接。有关使用示例,请参见下面的 ExampleFeed 类。

Changed in Django 1.9:

通过 item_enclosures 挂钩添加了每个Feed项目对多个机箱的支持。

语言

由联合框架创建的Feed自动包括适当的 <language> 标记(RSS 2.0)或 xml:lang 属性(Atom)。这直接来自您的 LANGUAGE_CODE 设置。

网址

link 方法/属性可以返回绝对路径(例如 "/blog/")或具有完全限定域和协议(例如 "https://www.example.com/blog/")的URL。如果 link 不返回域,联合框架将根据您的 SITE_ID setting 插入当前网站的域。

Atom订阅源需要一个 <link rel="self">,用于定义Feed的当前位置。联合框架根据 SITE_ID 设置使用当前站点的域自动填充此框架。

串联发布Atom和RSS Feed

一些开发人员喜欢提供他们的Feed的Atom and RSS版本。这很容易做到Django:只需创建一个你的 Feed 类的子类,并将 feed_type 设置为不同的东西。然后更新您的URLconf以添加额外的版本。

这里有一个完整的例子:

from django.contrib.syndication.views import Feed
from policebeat.models import NewsItem
from django.utils.feedgenerator import Atom1Feed

class RssSiteNewsFeed(Feed):
    title = "Police beat site news"
    link = "/sitenews/"
    description = "Updates on changes and additions to police beat central."

    def items(self):
        return NewsItem.objects.order_by('-pub_date')[:5]

class AtomSiteNewsFeed(RssSiteNewsFeed):
    feed_type = Atom1Feed
    subtitle = RssSiteNewsFeed.description

注解

在此示例中,RSS订阅源使用 description,而Atom订阅源使用 subtitle。这是因为Atom Feed不提供Feed级别的“说明”,但是 do 提供了一个“字幕”。

如果您在您的 Feed 类中提供 description,Django将 not 自动将其放入 subtitle 元素,因为字幕和描述不一定是同一件事。相反,您应该定义一个 subtitle 属性。

在上面的例子中,我们只需将Atom feed的 subtitle 设置为RSS feed的 description,因为它已经很短。

和附带的URLconf:

from django.conf.urls import url
from myproject.feeds import RssSiteNewsFeed, AtomSiteNewsFeed

urlpatterns = [
    # ...
    url(r'^sitenews/rss/$', RssSiteNewsFeed()),
    url(r'^sitenews/atom/$', AtomSiteNewsFeed()),
    # ...
]

Feed 类引用

class views.Feed

此示例说明了 Feed 类的所有可能的属性和方法:

from django.contrib.syndication.views import Feed
from django.utils import feedgenerator

class ExampleFeed(Feed):

    # FEED TYPE -- Optional. This should be a class that subclasses
    # django.utils.feedgenerator.SyndicationFeed. This designates
    # which type of feed this should be: RSS 2.0, Atom 1.0, etc. If
    # you don't specify feed_type, your feed will be RSS 2.0. This
    # should be a class, not an instance of the class.

    feed_type = feedgenerator.Rss201rev2Feed

    # TEMPLATE NAMES -- Optional. These should be strings
    # representing names of Django templates that the system should
    # use in rendering the title and description of your feed items.
    # Both are optional. If a template is not specified, the
    # item_title() or item_description() methods are used instead.

    title_template = None
    description_template = None

    # TITLE -- One of the following three is required. The framework
    # looks for them in this order.

    def title(self, obj):
        """
        Takes the object returned by get_object() and returns the
        feed's title as a normal Python string.
        """

    def title(self):
        """
        Returns the feed's title as a normal Python string.
        """

    title = 'foo' # Hard-coded title.

    # LINK -- One of the following three is required. The framework
    # looks for them in this order.

    def link(self, obj):
        """
        # Takes the object returned by get_object() and returns the URL
        # of the HTML version of the feed as a normal Python string.
        """

    def link(self):
        """
        Returns the URL of the HTML version of the feed as a normal Python
        string.
        """

    link = '/blog/' # Hard-coded URL.

    # FEED_URL -- One of the following three is optional. The framework
    # looks for them in this order.

    def feed_url(self, obj):
        """
        # Takes the object returned by get_object() and returns the feed's
        # own URL as a normal Python string.
        """

    def feed_url(self):
        """
        Returns the feed's own URL as a normal Python string.
        """

    feed_url = '/blog/rss/' # Hard-coded URL.

    # GUID -- One of the following three is optional. The framework looks
    # for them in this order. This property is only used for Atom feeds
    # (where it is the feed-level ID element). If not provided, the feed
    # link is used as the ID.

    def feed_guid(self, obj):
        """
        Takes the object returned by get_object() and returns the globally
        unique ID for the feed as a normal Python string.
        """

    def feed_guid(self):
        """
        Returns the feed's globally unique ID as a normal Python string.
        """

    feed_guid = '/foo/bar/1234' # Hard-coded guid.

    # DESCRIPTION -- One of the following three is required. The framework
    # looks for them in this order.

    def description(self, obj):
        """
        Takes the object returned by get_object() and returns the feed's
        description as a normal Python string.
        """

    def description(self):
        """
        Returns the feed's description as a normal Python string.
        """

    description = 'Foo bar baz.' # Hard-coded description.

    # AUTHOR NAME --One of the following three is optional. The framework
    # looks for them in this order.

    def author_name(self, obj):
        """
        Takes the object returned by get_object() and returns the feed's
        author's name as a normal Python string.
        """

    def author_name(self):
        """
        Returns the feed's author's name as a normal Python string.
        """

    author_name = 'Sally Smith' # Hard-coded author name.

    # AUTHOR EMAIL --One of the following three is optional. The framework
    # looks for them in this order.

    def author_email(self, obj):
        """
        Takes the object returned by get_object() and returns the feed's
        author's email as a normal Python string.
        """

    def author_email(self):
        """
        Returns the feed's author's email as a normal Python string.
        """

    author_email = 'test@example.com' # Hard-coded author email.

    # AUTHOR LINK --One of the following three is optional. The framework
    # looks for them in this order. In each case, the URL should include
    # the "http://" and domain name.

    def author_link(self, obj):
        """
        Takes the object returned by get_object() and returns the feed's
        author's URL as a normal Python string.
        """

    def author_link(self):
        """
        Returns the feed's author's URL as a normal Python string.
        """

    author_link = 'https://www.example.com/' # Hard-coded author URL.

    # CATEGORIES -- One of the following three is optional. The framework
    # looks for them in this order. In each case, the method/attribute
    # should return an iterable object that returns strings.

    def categories(self, obj):
        """
        Takes the object returned by get_object() and returns the feed's
        categories as iterable over strings.
        """

    def categories(self):
        """
        Returns the feed's categories as iterable over strings.
        """

    categories = ("python", "django") # Hard-coded list of categories.

    # COPYRIGHT NOTICE -- One of the following three is optional. The
    # framework looks for them in this order.

    def feed_copyright(self, obj):
        """
        Takes the object returned by get_object() and returns the feed's
        copyright notice as a normal Python string.
        """

    def feed_copyright(self):
        """
        Returns the feed's copyright notice as a normal Python string.
        """

    feed_copyright = 'Copyright (c) 2007, Sally Smith' # Hard-coded copyright notice.

    # TTL -- One of the following three is optional. The framework looks
    # for them in this order. Ignored for Atom feeds.

    def ttl(self, obj):
        """
        Takes the object returned by get_object() and returns the feed's
        TTL (Time To Live) as a normal Python string.
        """

    def ttl(self):
        """
        Returns the feed's TTL as a normal Python string.
        """

    ttl = 600 # Hard-coded Time To Live.

    # ITEMS -- One of the following three is required. The framework looks
    # for them in this order.

    def items(self, obj):
        """
        Takes the object returned by get_object() and returns a list of
        items to publish in this feed.
        """

    def items(self):
        """
        Returns a list of items to publish in this feed.
        """

    items = ('Item 1', 'Item 2') # Hard-coded items.

    # GET_OBJECT -- This is required for feeds that publish different data
    # for different URL parameters. (See "A complex example" above.)

    def get_object(self, request, *args, **kwargs):
        """
        Takes the current request and the arguments from the URL, and
        returns an object represented by this feed. Raises
        django.core.exceptions.ObjectDoesNotExist on error.
        """

    # ITEM TITLE AND DESCRIPTION -- If title_template or
    # description_template are not defined, these are used instead. Both are
    # optional, by default they will use the unicode representation of the
    # item.

    def item_title(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        title as a normal Python string.
        """

    def item_title(self):
        """
        Returns the title for every item in the feed.
        """

    item_title = 'Breaking News: Nothing Happening' # Hard-coded title.

    def item_description(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        description as a normal Python string.
        """

    def item_description(self):
        """
        Returns the description for every item in the feed.
        """

    item_description = 'A description of the item.' # Hard-coded description.

    def get_context_data(self, **kwargs):
        """
        Returns a dictionary to use as extra context if either
        description_template or item_template are used.

        Default implementation preserves the old behavior
        of using {'obj': item, 'site': current_site} as the context.
        """

    # ITEM LINK -- One of these three is required. The framework looks for
    # them in this order.

    # First, the framework tries the two methods below, in
    # order. Failing that, it falls back to the get_absolute_url()
    # method on each item returned by items().

    def item_link(self, item):
        """
        Takes an item, as returned by items(), and returns the item's URL.
        """

    def item_link(self):
        """
        Returns the URL for every item in the feed.
        """

    # ITEM_GUID -- The following method is optional. If not provided, the
    # item's link is used by default.

    def item_guid(self, obj):
        """
        Takes an item, as return by items(), and returns the item's ID.
        """

    # ITEM_GUID_IS_PERMALINK -- The following method is optional. If
    # provided, it sets the 'isPermaLink' attribute of an item's
    # GUID element. This method is used only when 'item_guid' is
    # specified.

    def item_guid_is_permalink(self, obj):
        """
        Takes an item, as returned by items(), and returns a boolean.
        """

    item_guid_is_permalink = False  # Hard coded value

    # ITEM AUTHOR NAME -- One of the following three is optional. The
    # framework looks for them in this order.

    def item_author_name(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        author's name as a normal Python string.
        """

    def item_author_name(self):
        """
        Returns the author name for every item in the feed.
        """

    item_author_name = 'Sally Smith' # Hard-coded author name.

    # ITEM AUTHOR EMAIL --One of the following three is optional. The
    # framework looks for them in this order.
    #
    # If you specify this, you must specify item_author_name.

    def item_author_email(self, obj):
        """
        Takes an item, as returned by items(), and returns the item's
        author's email as a normal Python string.
        """

    def item_author_email(self):
        """
        Returns the author email for every item in the feed.
        """

    item_author_email = 'test@example.com' # Hard-coded author email.

    # ITEM AUTHOR LINK -- One of the following three is optional. The
    # framework looks for them in this order. In each case, the URL should
    # include the "http://" and domain name.
    #
    # If you specify this, you must specify item_author_name.

    def item_author_link(self, obj):
        """
        Takes an item, as returned by items(), and returns the item's
        author's URL as a normal Python string.
        """

    def item_author_link(self):
        """
        Returns the author URL for every item in the feed.
        """

    item_author_link = 'https://www.example.com/' # Hard-coded author URL.

    # ITEM ENCLOSURES -- One of the following three is optional. The
    # framework looks for them in this order. If one of them is defined,
    # ``item_enclosure_url``, ``item_enclosure_length``, and
    # ``item_enclosure_mime_type`` will have no effect.

    def item_enclosures(self, item):
        """
        Takes an item, as returned by items(), and returns a list of
        ``django.utils.feedgenerator.Enclosure`` objects.
        """

    def item_enclosures(self):
        """
        Returns the ``django.utils.feedgenerator.Enclosure`` list for every
        item in the feed.
        """

    item_enclosures = []  # Hard-coded enclosure list

    # ITEM ENCLOSURE URL -- One of these three is required if you're
    # publishing enclosures and you're not using ``item_enclosures``. The
    # framework looks for them in this order.

    def item_enclosure_url(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        enclosure URL.
        """

    def item_enclosure_url(self):
        """
        Returns the enclosure URL for every item in the feed.
        """

    item_enclosure_url = "/foo/bar.mp3" # Hard-coded enclosure link.

    # ITEM ENCLOSURE LENGTH -- One of these three is required if you're
    # publishing enclosures and you're not using ``item_enclosures``. The
    # framework looks for them in this order. In each case, the returned
    # value should be either an integer, or a string representation of the
    # integer, in bytes.

    def item_enclosure_length(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        enclosure length.
        """

    def item_enclosure_length(self):
        """
        Returns the enclosure length for every item in the feed.
        """

    item_enclosure_length = 32000 # Hard-coded enclosure length.

    # ITEM ENCLOSURE MIME TYPE -- One of these three is required if you're
    # publishing enclosures and you're not using ``item_enclosures``. The
    # framework looks for them in this order.

    def item_enclosure_mime_type(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        enclosure MIME type.
        """

    def item_enclosure_mime_type(self):
        """
        Returns the enclosure MIME type for every item in the feed.
        """

    item_enclosure_mime_type = "audio/mpeg" # Hard-coded enclosure MIME type.

    # ITEM PUBDATE -- It's optional to use one of these three. This is a
    # hook that specifies how to get the pubdate for a given item.
    # In each case, the method/attribute should return a Python
    # datetime.datetime object.

    def item_pubdate(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        pubdate.
        """

    def item_pubdate(self):
        """
        Returns the pubdate for every item in the feed.
        """

    item_pubdate = datetime.datetime(2005, 5, 3) # Hard-coded pubdate.

    # ITEM UPDATED -- It's optional to use one of these three. This is a
    # hook that specifies how to get the updateddate for a given item.
    # In each case, the method/attribute should return a Python
    # datetime.datetime object.

    def item_updateddate(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        updateddate.
        """

    def item_updateddate(self):
        """
        Returns the updateddate for every item in the feed.
        """

    item_updateddate = datetime.datetime(2005, 5, 3) # Hard-coded updateddate.

    # ITEM CATEGORIES -- It's optional to use one of these three. This is
    # a hook that specifies how to get the list of categories for a given
    # item. In each case, the method/attribute should return an iterable
    # object that returns strings.

    def item_categories(self, item):
        """
        Takes an item, as returned by items(), and returns the item's
        categories.
        """

    def item_categories(self):
        """
        Returns the categories for every item in the feed.
        """

    item_categories = ("python", "django") # Hard-coded categories.

    # ITEM COPYRIGHT NOTICE (only applicable to Atom feeds) -- One of the
    # following three is optional. The framework looks for them in this
    # order.

    def item_copyright(self, obj):
        """
        Takes an item, as returned by items(), and returns the item's
        copyright notice as a normal Python string.
        """

    def item_copyright(self):
        """
        Returns the copyright notice for every item in the feed.
        """

    item_copyright = 'Copyright (c) 2007, Sally Smith' # Hard-coded copyright notice.

低级框架

在后台,高级RSS框架使用较低级别的框架来生成订阅源的XML。这个框架存在于单个模块中:django/utils/feedgenerator.py

您自己使用此框架,用于生成较低级别的Feed。您还可以创建自定义Feed生成器子类以与 feed_type Feed 选项一起使用。

SyndicationFeed

feedgenerator 模块包含一个基类:

和几个子类:

这三个类中的每一个都知道如何将某种类型的feed呈现为XML。他们共享这个接口:

SyndicationFeed.__init__()

使用给定的元数据字典初始化Feed,该元数据字典应用于整个Feed。必需的关键字参数为:

  • title

  • link

  • description

还有一堆其他可选关键字:

  • language

  • author_email

  • author_name

  • author_link

  • subtitle

  • categories

  • feed_url

  • feed_copyright

  • feed_guid

  • ttl

任何传递给 __init__ 的额外关键字参数将存储在 self.feed 中,以便与 custom feed generators 一起使用。

所有参数都应该是Unicode对象,除了 categories,它应该是一个Unicode对象序列。请注意,某些控制字符是XML文档中的 不允许。如果您的内容中有部分内容,则在制作Feed时可能会遇到 ValueError

SyndicationFeed.add_item()

向具有给定参数的Feed中添加项目。

必需的关键字参数为:

  • title

  • link

  • description

可选的关键字参数为:

  • author_email

  • author_name

  • author_link

  • pubdate

  • comments

  • unique_id

  • enclosure

  • enclosures

  • categories

  • item_copyright

  • ttl

  • updateddate

将为 custom feed generators 存储额外的关键字参数。

所有参数,如果给定,应该是Unicode对象,除了:

1.9 版后已移除: enclosure 关键字参数已弃用,以支持 enclosures 关键字参数。

SyndicationFeed.write()

将给定编码中的Feed输出为outfile,它是一个类文件对象。

SyndicationFeed.writeString()

以给定编码中的字符串形式返回Feed。

例如,要创建Atom 1.0订阅源并将其打印到标准输出:

>>> from django.utils import feedgenerator
>>> from datetime import datetime
>>> f = feedgenerator.Atom1Feed(
...     title="My Weblog",
...     link="https://www.example.com/",
...     description="In which I write about what I ate today.",
...     language="en",
...     author_name="Myself",
...     feed_url="https://example.com/atom.xml")
>>> f.add_item(title="Hot dog today",
...     link="https://www.example.com/entries/1/",
...     pubdate=datetime.now(),
...     description="<p>Today I had a Vienna Beef hot dog. It was pink, plump and perfect.</p>")
>>> print(f.writeString('UTF-8'))
<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">
...
</feed>

自定义Feed生成器

如果您需要生成自定义Feed格式,您有几个选项。

如果Feed格式是完全自定义的,您需要将 SyndicationFeed 子类化并完全替换 write()writeString() 方法。

但是,如果Feed格式是RSS或Atom的分支(即 GeoRSS,Apple的 iTunes podcast format 等),则您有更好的选择。这些类型的feed通常向底层格式添加额外的元素和/或属性,并且有一组方法,SyndicationFeed 调用以获得这些额外的属性。因此,您可以对相应的Feed生成器类(Atom1FeedRss201rev2Feed)进行子类化,并扩展这些回调。他们是:

SyndicationFeed.root_attributes(self, )

返回要添加到根馈给元素(feed/channel)的属性的 dict

SyndicationFeed.add_root_elements(self, handler)

回调以在根馈送元素(feed/channel)中添加元素。 handler 是来自Python内置的SAX库的 XMLGenerator;你将调用它上面的方法来添加到正在处理的XML文档。

SyndicationFeed.item_attributes(self, item)

返回 dict 的属性以添加到每个项目(item/entry)元素。参数 item 是传递给 SyndicationFeed.add_item() 的所有数据的字典。

SyndicationFeed.add_item_elements(self, handler, item)

回调为每个项目(item/entry)元素添加元素。 handleritem 如上所述。

警告

如果您覆盖任何这些方法,请务必调用超类方法,因为它们为每种Feed格式添加了必需的元素。

例如,您可能开始实现iTunes RSS Feed生成器:

class iTunesFeed(Rss201rev2Feed):
    def root_attributes(self):
        attrs = super(iTunesFeed, self).root_attributes()
        attrs['xmlns:itunes'] = 'http://www.itunes.com/dtds/podcast-1.0.dtd'
        return attrs

    def add_root_elements(self, handler):
        super(iTunesFeed, self).add_root_elements(handler)
        handler.addQuickElement('itunes:explicit', 'clean')

显然,对于一个完整的自定义feed类,还有很多工作要做,但上面的例子应该展示基本的想法。