联合提要框架 — Django 文档

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Django/docs/2.2.x/ref/contrib/syndication
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Feed 聚合框架

Django 附带了一个高级联合提要生成框架,可以轻松创建 RSSAtom 提要。

要创建任何联合提要,您所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提要。

Django 还带有一个较低级别的提要生成 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提要,请使用此选项。

高级框架

概况

高级提要生成框架由 Feed 类提供。 要创建提要,请编写一个 Feed 类并在您的 URLconf 中指向它的一个实例。


Feed 类

Feed 类是表示联合提要的 Python 类。 提要可以很简单(例如,“站点新闻”提要,或显示博客最新条目的基本提要)或更复杂(例如,显示特定类别中所有博客条目的提要,其中类别是可变的)。

提要类子类 django.contrib.syndication.views.Feed。 它们可以存在于您的代码库中的任何位置。

Feed 类的实例是可以在 URLconf 中使用的视图。


一个简单的例子

这个简单的例子取自一个假设的警察节拍新闻网站,描述了最新五个新闻项目的提要:

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 对象的实例放入您的 URLconf。 例如:

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

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

注意:

  • Feed 类是 django.contrib.syndication.views.Feed 的子类。
  • titlelinkdescription 分别对应于标准 RSS <title><link><description> 元素。
  • items() 简单地说,就是一个方法,它返回一个对象列表,这些对象应该作为 <item> 元素包含在提要中。 尽管此示例使用 Django 的 对象关系映射器 返回 NewsItem 对象,但 items() 不必返回模型实例。 尽管您可以通过使用 Django 模型“免费”获得一些功能,但 items() 可以返回您想要的任何类型的对象。
  • 如果您要创建 Atom 提要,而不是 RSS 提要,请设置 subtitle 属性而不是 description 属性。 有关示例,请参阅稍后的 串联发布 Atom 和 RSS 提要

剩下要做的一件事。 在 RSS 提要中,每个 <item> 都有一个 <title><link><description>。 我们需要告诉框架将哪些数据放入这些元素中。

  • 对于 <title><description> 的内容,Django 尝试调用 Feed 类上的方法 item_title()item_description()。 它们被传递一个参数,item,它是对象本身。 这些是可选的; 默认情况下,对象的字符串表示用于两者。

    如果你想对标题或描述做任何特殊的格式化,可以使用 Django 模板 代替。 它们的路径可以用 Feed 类上的 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:

    请参阅下面的 使用描述模板的复杂示例

    Feed.get_context_data(**kwargs)

    如果您需要提供比前面提到的两个变量更多的变量,还有一种方法可以将附加信息传递给标题和描述模板。 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().get_context_data(**kwargs)
            context['foo'] = 'bar'
            return context

    还有模板:

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

    此方法将针对 items() 返回的列表中的每个项目使用以下关键字参数调用一次:

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

    • objget_object()返回的对象。 默认情况下,这不会暴露给模板以避免与 模板:Obj(见上文)混淆,但您可以在 get_context_data() 的实现中使用它。

    • site:如上所述的当前站点。

    • request:当前请求。

    get_context_data() 的行为模仿 通用视图 的行为 - 您应该调用 super() 从父类检索上下文数据,添加数据并返回修改后的字典。

  • 要指定 <link> 的内容,您有两种选择。 对于 items() 中的每个项目,Django 首先尝试调用 Feed 类上的 item_link() 方法。 与标题和描述类似,它传递了一个参数,item。 如果该方法不存在,Django 会尝试对该对象执行 get_absolute_url() 方法。 get_absolute_url()item_link() 都应该以普通 Python 字符串的形式返回项目的 URL。 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部进行所有必要的 URL 引用和转换为 ASCII。


一个复杂的例子

该框架还支持更复杂的 feed,通过参数。

例如,一个网站可以为一个城市的每一个警察殴打提供最近犯罪的 RSS 提要。 为每个警察节拍创建一个单独的 Feed 类是愚蠢的; 这将违反 DRY 原则 ,并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,以便提要可以根据提要 URL 中的信息输出项目。

可以通过这样的网址访问警察局 feed:

  • /beats/613/rss/ – 返回第 613 节的最近犯罪。
  • /beats/1424/rss/ – 返回第 1424 节的最近犯罪。

这些可以与 URLconf 行匹配,例如:

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

像视图一样,URL 中的参数与请求对象一起传递给 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]

要生成提要的 <title><link><description>,Django 使用 title()link()description() 方法。 在前面的示例中,它们是简单的字符串类属性,但此示例说明它们可以是字符串 方法。 对于 titlelinkdescription 中的每一个,Django 遵循以下算法:

  • 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。
  • 如果失败了,它就会尝试调用一个没有参数的方法。
  • 如果失败了,它就会使用类属性。

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

我们正在为项目描述使用模板。 它可以非常简单:

{{ obj.description }}

但是,你可以根据需要自由添加格式。

下面的 ExampleFeed 类给出了关于 Feed 类的方法和属性的完整文档。


指定 feed 的类型

默认情况下,这个框架中产生的 feed 使用 RSS 2.0。

要更改它,请将 feed_type 属性添加到您的 Feed 类,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 类型有:


封面

要指定附件,例如用于创建播客提要的附件,请使用 item_enclosures 挂钩,或者,如果每个项目只有一个附件,则使用 item_enclosure_urlitem_enclosure_length , 和 item_enclosure_mime_type 挂钩。 有关用法示例,请参阅下面的 ExampleFeed 类。


语言

联合框架创建的提要自动包含适当的 <language> 标签 (RSS 2.0) 或 xml:lang 属性 (Atom)。 这直接来自您的 :setting:`LANGUAGE_CODE` 设置。


网址

link 方法/属性可以返回一个绝对路径(例如 "/blog/") 或具有完全限定域和协议的 URL(例如 "https://www.example.com/blog/%22)。 如果link不返回域,联合框架将插入当前站点的域,根据您的 :setting:`SITE_ID 设置 ` .

Atom 提要需要一个 <link rel="self"> 来定义提要的当前位置。 联合框架根据 :setting:`SITE_ID` 设置使用当前站点的域自动填充它。


同时发布 Atom 和 RSS feed

一些开发人员喜欢提供 Atom RSS 版本的提要。 用 Django 做到这一点很容易:只需创建 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

笔记

在此示例中,RSS 提要使用 description,而 Atom 提要使用 subtitle。 这是因为 Atom 提要不提供提要级别的“描述”,但它们 确实 提供了“字幕”。

如果您在 Feed 类中提供 description,Django 将 not 自动将其放入 subtitle 元素中,因为副标题和描述不是必然是同一件事。 相反,您应该定义 subtitle 属性。

在上面的示例中,我们只是将 Atom 提要的 subtitle 设置为 RSS 提要的 description,因为它已经很短了。


以及随附的 URLconf:

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

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

Feed 类参考

class views.Feed

此示例说明 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,高级 RSS 框架使用低级框架来生成提要的 XML。 该框架存在于单个模块中::source:`django/utils/feedgenerator.py`

您可以自己使用此框架来生成较低级别的提要。 您还可以创建自定义提要生成器子类以与 feed_type Feed 选项一起使用。

SyndicationFeed 类

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提要呈现为 XML。 他们共享这个接口:

SyndicationFeed.__init__()

使用给定的元数据字典初始化提要,该字典适用于整个提要。 必须的关键字参数是:

  • 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

您传递给 __init__ 的任何额外关键字参数都将存储在 self.feed 中,以便与 自定义提要生成器 一起使用。

所有参数都应该是字符串,除了 categories,它应该是一个字符串序列。 请注意,某些控制字符在 XML 文档中 不允许 。 如果您的内容包含其中一些,则在生成提要时可能会遇到 ValueError

SyndicationFeed.add_item()

用给定的参数将一个项目添加到 feed 中。

必须的关键字参数是:

  • title

  • link

  • description

可选的关键字参数是:

  • author_email

  • author_name

  • author_link

  • pubdate

  • comments

  • unique_id

  • enclosures

  • categories

  • item_copyright

  • ttl

  • updateddate

将为 自定义提要生成器 存储额外的关键字参数。

所有参数,如果给定,都应该是字符串,除了:

  • pubdate 应该是一个 Python datetime 对象。

  • updateddate 应该是一个 Python datetime 对象。

  • enclosures 应该是 django.utils.feedgenerator.Enclosure 实例的列表。

  • categories 应该是一个字符串序列。

SyndicationFeed.write()

将给定编码的 feed 输出到 outfile,一个类似文件的对象。

SyndicationFeed.writeString()

以给定编码的字符串形式返回 feed。

例如,要创建 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提要格式,您有几个选择。

如果提要格式是完全自定义的,您需要子类化 SyndicationFeed 并完全替换 write()writeString() 方法。

但是,如果提要格式是 RSS 或 Atom 的衍生品(即 GeoRSS、苹果的iTunes 播客格式等),你有更好的选择。 这些类型的提要通常会向底层格式添加额外的元素和/或属性,并且有一组 SyndicationFeed 调用的方法来获取这些额外的属性。 因此,您可以子类化适当的提要生成器类(Atom1FeedRss201rev2Feed)并扩展这些回调。 他们是:

SyndicationFeed.root_attributes(self)
返回 dict 属性以添加到根提要元素 (feed/channel)。
SyndicationFeed.add_root_elements(self, handler)
回调以在根提要元素 (feed/channel) 内添加元素。 handler 是来自 Python 内置 SAX 库的 XMLGenerator; 您将调用它的方法以添加到正在处理的 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)
回调以向每个项目 (item/entry) 元素添加元素。 handleritem 同上。

警告

如果你覆盖了这些方法中的任何一个,一定要调用超级类方法,因为它们为每种 feed 格式添加了所需的元素。


例如,您可能会开始实现一个 iTunes RSS 提要生成器,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')

显然,一个完整的自定义提要类还有很多工作要做,但上面的例子应该展示了基本思想。