我正在使用 Django Feeds Framework，它非常好，非常直观且易于使用。但是，我认为在 HTML 中创建指向提要的链接时存在问题。
例如：
<link rel="alternate" type="application/rss+xml" title="{{ feed_title }}" href="{{ url_of_feed }}" />
链接的HREF属性很容易找到，只需使用reverse()
但是，TITLE属性呢？模板引擎应该在哪里寻找这个？更重要的是，如果提要是动态构建的并且标题取决于参数（像这样）怎么办？
我想不出一个对我来说“似乎”干的解决方案......我能想出的只是使用上下文处理器或模板标签，但是当上下文处理器/模板标签必须找到参数时它会变得混乱构建 Feed 类，并写下这个我意识到我什至不知道如何在视图中自己创建一个 Feed 实例。
如果我把所有这些逻辑都放在视图中，它就不仅仅是一个视图。此外， 的值TITLE将在视图和提要中。
只是一个猜测（因为我还没有在我的 django 应用程序中使用提要），但是您可以使用提要对象为提要添加一个特殊的 template_context 并在 base.html 中使用它。
我对这个解决方案并不完全满意，它可能会破坏提要，Request并且依赖于一种神奇的方法。它是这样的：
#coding:utf-8
# Author: Armando Pérez Marqués <mandx@rbol.org>
# Purpose: Django TemplateTag to output feed links in templates in a DRY way
# Created: 05/07/2010
import re
from django import template
from django.conf import settings
from django.contrib.syndication.views import Feed
from django.core.urlresolvers import reverse, resolve, NoReverseMatch
from django.template import Node
from django.template import TemplateSyntaxError
from django.utils.encoding import smart_str
from django.utils.html import escape as html_escape
from django.utils.safestring import mark_safe
register = template.Library()
kwarg_re = re.compile(r"(?:(\w+)=)?(.+)")
class FeedInfoNode(Node):
def __init__(self, view_name, args, kwargs, asvar):
self.view_name = view_name
self.args = args
self.kwargs = kwargs
self.asvar = asvar
def render(self, context):
args = [arg.resolve(context) for arg in self.args]
kwargs = dict([(smart_str(k,'ascii'), v.resolve(context))
for k, v in self.kwargs.items()])
# Try to look up the URL twice: once given the view name, and again
# relative to what we guess is the "main" app. If they both fail,
# re-raise the NoReverseMatch unless we're using the
# {% feed_info ... as var %} construct in which cause return nothing.
url = ''
try:
url = reverse(self.view_name, args=args, kwargs=kwargs, current_app=context.current_app)
except NoReverseMatch, e:
if settings.SETTINGS_MODULE:
project_name = settings.SETTINGS_MODULE.split('.')[0]
try:
url = reverse(project_name + '.' + self.view_name,
args=args, kwargs=kwargs, current_app=context.current_app)
except NoReverseMatch:
if self.asvar is None:
# Re-raise the original exception, not the one with
# the path relative to the project. This makes a
# better error message.
raise e
else:
if self.asvar is None:
raise e
if 'request' in context:
request = context['request']
else:
request = None
feed_instance, feed_args, feed_kwargs = resolve(url)
if not isinstance(feed_instance, Feed):
raise NoReverseMatch, \
'feed_info can only reverse class-based feeds'
feed_obj = feed_instance.get_object(request, *feed_args, **feed_kwargs)
feed_data = {
'url': url,
'obj': feed_instance,
'args': feed_args,
'kwargs': feed_kwargs,
#'title': html_escape(feed_instance.__get_dynamic_attr('title', obj)),
'title': html_escape(
feed_instance._Feed__get_dynamic_attr('title', feed_obj)
),
'type': feed_instance.feed_type.mime_type,
}
if self.asvar:
context[self.asvar] = feed_data
return ''
else:
return mark_safe(
'<link rel="alternate" type="%(type)s" title="%(title)s" href="%(url)s" />' \
% feed_data
)
def feed_info(parser, token):
"""
Returns an mapping containing populated info about the reversed feed
Works exactly as the url tag, but the mapping is not returned, instead
a variable is always set in the context.
This is a way to define links that aren't tied to a particular URL
configuration::
{% feed_info path.to.some_feed_view_class arg1 arg2 as feed_info_var %}
or
{% feed_info path.to.some_feed_view_class name1=value1 name2=value2 as feed_info_var %}
"""
bits = token.split_contents()
if len(bits) < 2:
raise TemplateSyntaxError("'%s' takes at least one argument"
" (path to a feed view)" % bits[0])
viewname = bits[1]
args = []
kwargs = {}
asvar = None
bits = bits[2:]
if len(bits) >= 2 and bits[-2] == 'as':
asvar = bits[-1]
bits = bits[:-2]
# Backwards compatibility: check for the old comma separated format
# {% url urlname arg1,arg2 %}
# Initial check - that the first space separated bit has a comma in it
if bits and ',' in bits[0]:
check_old_format = True
# In order to *really* be old format, there must be a comma
# in *every* space separated bit, except the last.
for bit in bits[1:-1]:
if ',' not in bit:
# No comma in this bit. Either the comma we found
# in bit 1 was a false positive (e.g., comma in a string),
# or there is a syntax problem with missing commas
check_old_format = False
break
else:
# No comma found - must be new format.
check_old_format = False
if check_old_format:
# Confirm that this is old format by trying to parse the first
# argument. An exception will be raised if the comma is
# unexpected (i.e. outside of a static string).
match = kwarg_re.match(bits[0])
if match:
value = match.groups()[1]
try:
parser.compile_filter(value)
except TemplateSyntaxError:
bits = ''.join(bits).split(',')
# Now all the bits are parsed into new format,
# process them as template vars
if len(bits):
for bit in bits:
match = kwarg_re.match(bit)
if not match:
raise TemplateSyntaxError("Malformed arguments to url tag")
name, value = match.groups()
if name:
kwargs[name] = parser.compile_filter(value)
else:
args.append(parser.compile_filter(value))
return FeedInfoNode(viewname, args, kwargs, asvar)
feed_info = register.tag(feed_info)
我从{% url %}模板标签的代码开始，然后，在获取到feed的URL后，使用resolve()来获取Feed子类实例，然后获取需要的属性。
注意事项
request 上下文处理器None，因为如果它不存在于上下文中，则传递。