联合供稿框架

Django提供了一个高级别的联合供稿生成框架,可以轻松地创建RSSAtom

要创建任何联合供稿,您只需编写一个简短的Python类。 您可以根据需要创建尽可能多的Feed。

Django还附带了一个较低级别的Feed生成API。 如果要在Web上下文之外或其他更低级别的方式中生成提要,请使用此选项。

高级框架

概述¶ T0>

高级Feed生成框架由Feed类提供。 要创建一个feed,请写一个Feed类,并在你的URLconf中指向它的一个实例。

Feed

一个Feed类是一个表示联合供稿的Python类。 Feed可以是简单的(例如,“网站新闻”Feed或显示博客的最新条目的基本Feed)或更复杂的(例如,显示特定类别中的所有博客条目的Feed )。

Feed类的子类django.contrib.syndication.views.Feed 他们可以生活在你的代码库的任何地方。

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,来自一个假设的警察新闻网站,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连接到此提要,请将Feed对象的实例放入URLconf中。 例如:

from django.urls import path
from myproject.feeds import LatestEntriesFeed

urlpatterns = [
    # ...
    path('latest/feed/', LatestEntriesFeed()),
    # ...
]

注意:

  • Feed类的子类django.contrib.syndication.views.Feed
  • title, link and description correspond to the standard RSS <title>, <link> and <description> elements, respectively.
  • items() is, simply, a method that returns a list of objects that should be included in the feed as <item> elements. Although this example returns NewsItem objects using Django’s object-relational mapper, items() doesn’t have to return model instances. 虽然使用Django模型“免费”获得了一些功能,但是items()可以返回任何类型的对象。
  • 如果要创建Atom提要而不是RSS提要,请设置subtitle属性而不是description属性。 稍后参见发布Atom和RSS提要,作为示例。

还有一件事要做。 In an RSS feed, each <item> has a <title>, <link> and <description>. 我们需要告诉框架将哪些数据放入这些元素。

  • For the contents of <title> and <description>, Django tries calling the methods item_title() and item_description() on the Feed class. 他们传递了一个参数,item,它是对象本身。 这些是可选的;默认情况下,该对象的字符串表示被用于两者。

    如果您想对标题或描述进行特殊的格式化,可以使用Django templates 它们的路径可以通过Feed类中的title_templatedescription_template属性指定。 为每个项目呈现模板并传递两个模板上下文变量:

    请参阅下面使用描述模板的复杂示例

    饲料。 get_context_data T0>( ** kwargs T1>)¶ T2>

    如果您需要提供比前面提到的两个变量更多的信息,还可以将其他信息传递给标题和描述模板。 您可以在您的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().get_context_data(**kwargs)
            context['foo'] = 'bar'
            return context
    

    和模板:

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

    这个方法将被items()返回的列表中的每个项目调用一次,其关键字参数如下:

    • item: the current item. 为了兼容性的原因,这个上下文变量的名字是{{ obj }}
    • obj:由get_object()返回的对象。 默认情况下,这不会暴露给模板,以避免与{{ obj }}混淆(见上文) ,但可以在实现get_context_data()时使用它。
    • site:如上所述的当前网站。
    • request: current request.

    The behavior of get_context_data() mimics that of generic views - you’re supposed to call super() to retrieve context data from parent class, add your data and return the modified dictionary.

  • 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类中的item_link()方法。 In a similar way to the title and description, it is passed it a single parameter, item. 如果该方法不存在,Django会尝试在该对象上执行get_absolute_url()方法。 Both get_absolute_url() and item_link() should return the item’s URL as a normal Python string. get_absolute_url()一样,item_link()的结果将直接包含在URL中,因此您需要负责在URL中进行所有必要的URL引用和转换。方法本身。

一个复杂的例子

该框架还通过参数支持更复杂的提要。

例如,一个网站可以提供每个警察在城市中最近犯罪的RSS源。 It’d be silly to create a separate Feed class for each police beat; that would violate the DRY principle and would couple data to programming logic. 相反,联合框架允许您访问从URLconf传递的参数,以便提要可以根据Feed的URL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/ - 返回节拍613的近期犯罪。
  • /beats/1424/rss/ - 返回最近的1424次犯罪。

这些可以与URLconf行匹配,例如:

path('beats/<int:beat_id>/rss/', BeatFeed()),

就像一个视图一样,URL中的参数和请求对象一起被传递给get_object()方法。

以下是这些特定于节拍的提要的代码:

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]

To generate the feed’s <title>, <link> and <description>, Django uses the title(), link() and description() methods. 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方法。 对于titlelinkdescription中的每一个,Django都遵循以下算法:

  • 首先,它会尝试调用一个方法,传递obj参数,其中obj是由get_object()返回的对象。
  • 否则,它会尝试调用一个没有参数的方法。
  • 否则,它使用类属性。

Also note that items() also follows the same algorithm – first, it tries items(obj), then items(), then finally an items class attribute (which should be a list).

我们正在使用项目描述的模板。 它可以非常简单:

{{ 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Feed类的方法和属性的完整文档。

指定供稿的类型

默认情况下,此框架中生成的供稿使用RSS 2.0。

要改变这个,给你的Feed类添加一个feed_type属性,如下所示:

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类型是:

外壳¶ T0>

要指定附件(如用于创建Podcast Feed的附件),请使用item_enclosures挂钩,或者,如果每个项目只有一个附件,item_enclosure_urlitem_enclosure_lengthitem_enclosure_mime_type挂钩。 有关使用示例,请参阅下面的ExampleFeed类。

语言¶ T0>

由联合框架创建的源自动包含适当的<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¶ T0>

link方法/属性可以返回绝对路径(例如"/blog/")或带有完全限定的域和协议的URL(例如"https://www.example.com/blog/" 如果link没有返回域,联合框架会根据您的SITE_ID setting

Atom提要需要&lt; link rel =“self”&gt;来定义提要的当前位置。 联合框架根据SITE_ID设置自动填充当前站点的域。

共同发布Atom和RSS feed

一些开发者喜欢提供他们的Feed的Atom RSS版本。 使用Django很容易:只需创建一个Feed类的子类,并将feed_type设置为不同的东西。 然后更新你的URLconf来添加额外的版本。

这是一个完整的例子:

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

注意

在本例中,RSS提要使用description,而Atom提要使用subtitle That’s because Atom feeds don’t provide for a feed-level “description,” but they do provide for a “subtitle.”

如果您在Feed类中提供description,则Django将不自动将subtitle 相反,你应该定义一个subtitle属性。

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

和随附的URLconf:

from django.urls import path
from myproject.feeds import RssSiteNewsFeed, AtomSiteNewsFeed

urlpatterns = [
    # ...
    path('sitenews/rss/', RssSiteNewsFeed()),
    path('sitenews/atom/', AtomSiteNewsFeed()),
    # ...
]

Feed类引用

观点。饲料 T0> ¶ T1>

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 string 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

在幕后,高层次的RSS框架使用较低层的框架来生成提要的XML。 这个框架存在于一个模块中:django / utils / feedgenerator.py

您可以自己使用此框架,以生成较低级别的Feed。 您还可以创建与feed_type Feed选项一起使用的自定义Feed生成器子类。

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。 他们分享这个接口:

SyndicationFeed .__的init __()

使用适用于整个Feed的元数据字典初始化Feed。 所需的关键字参数是:

  • 标题
  • 链接
  • 描述

还有其他一些可选的关键字:

  • 语言
  • AUTHOR_EMAIL
  • AUTHOR_NAME
  • author_link
  • 字幕
  • 类别
  • FEED_URL
  • feed_copyright
  • feed_guid
  • TTL

您传递给__init__的任何额外关键字参数将存储在self.feed中,以便与自定义Feed生成器一起使用。

所有参数都应该是字符串,除了categories,它应该是一串字符串。 Beware that some control characters are not allowed in XML documents. 如果你的内容有一些,你可能会遇到一个ValueError生产饲料。

SyndicationFeed.add_item()

使用给定参数向Feed添加项目。

所需的关键字参数是:

  • 标题
  • 链接
  • 描述

可选的关键字参数是:

  • AUTHOR_EMAIL
  • AUTHOR_NAME
  • author_link
  • pubdate的
  • 注释
  • 唯一身份
  • 机箱
  • 类别
  • item_copyright
  • TTL
  • updateddate

额外的关键字参数将被存储为定制的饲料生成器

所有参数,如果给出,应该是字符串,除了:

SyndicationFeed.write()
将给定编码中的feed输出到outfile,这是一个类似文件的对象。
SyndicationFeed.writeString()
以给定编码中的字符串形式返回提要。

例如,要创建一个Atom 1.0提要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,则有几个选项。

如果Feed格式是完全自定义的,那么您需要继承SyndicationFeed并完全替换write()writeString()方法。

However, if the feed format is a spin-off of RSS or Atom (i.e. GeoRSS, Apple’s iTunes podcast format, etc.), you’ve got a better choice. These types of feeds typically add extra elements and/or attributes to the underlying format, and there are a set of methods that SyndicationFeed calls to get these extra attributes. 因此,您可以继承相应的Feed生成器类(Atom1FeedRss201rev2Feed)并扩展这些回调。 他们是:

SyndicationFeed.root_attributes(self,
返回属性的dict以添加到根提要元素(feed / channel)。
SyndicationFeed.add_root_elements(self, 处理程序)
回调在根Feed元素(feed / channel)内添加元素。 handler是Python内置的SAX库中的XMLGenerator您将调用其中的方法来添加到正在处理的XML文档中。
SyndicationFeed.item_attributes(self, item)
返回属性的dict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)
回调为每个项目添加元素(item / entry)元素。 handleritem如上所述。

警告

如果您重写这些方法中的任何一个,请务必调用超类方法,因为它们为每个提要格式添加了必需的元素。

例如,您可能会开始实施iTunes RSS Feed生成器,如下所示:

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

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

很明显,要完成一个完整的自定义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。