Question

I want to provide rss feed under google app engine/python.

I’ve tried to use usual request handler and generate xml response. When I access the feed url directly, I can see the feed correctly, however, when I’m trying to subscribe to the feed in google reader, it says that

‘The feed being requested cannot be found.’

I wonder whether this approach is right. I was considering using a static xml file and updating it by cron jobs. But while GAE doesn’t support file i/o, this approach seems not going to work.

How to solve this? Thanks!

Answer 1

There’re 2 solutions I suggest:

1. GAE-REST you can just add to your project and configure and it will make RSS for you but the project is old and no longer maintained.

2. Do like I do, use a template to write a list to and like this I could succeed generating RSS (GeoRSS) that can be read via google reader where template is:

   <title>{{host}}</title>
   <link href="http://{{host}}" rel="self"/>
   <id>http://{{host}}/</id>
   <updated>2011-09-17T08:14:49.875423Z</updated>
   <generator uri="http://{{host}}/">{{host}}</generator>
   
   {% for entity in entities %}
   
   <entry>
   
   <title><![CDATA[{{entity.title}}]]></title>
   <link href="http://{{host}}/vi/{{entity.key.id}}"/>
   <id>http://{{host}}/vi/{{entity.key.id}}</id>
   <updated>{{entity.modified.isoformat}}Z</updated>
   <author><name>{{entity.title|escape}}</name></author>
   <georss:point>{{entity.geopt.lon|floatformat:2}},{{entity.geopt.lat|floatformat:2}}</georss:point>
   <published>{{entity.added}}</published>
   <summary type="xhtml"><div xmlns="http://www.w3.org/1999/xhtml">{{entity.text|escape}}</div>
   </summary>
   
   </entry>
   
   {% endfor %}
   
   </feed>
   

My handler is (you can also do this with python 2.7 as just a function outside a handler for a more minimal solution):

class GeoRSS(webapp2.RequestHandler):

    def get(self):
        start = datetime.datetime.now() - timedelta(days=60)
        count = (int(self.request.get('count'
                 )) if not self.request.get('count') == '' else 1000)
        try:
            entities = memcache.get('entities')
        except KeyError:
            entity = Entity.all().filter('modified >',
                                  start).filter('published =',
                    True).order('-modified').fetch(count)
        memcache.set('entities', entities)
        template_values = {'entities': entities, 'request': self.request,
                           'host': os.environ.get('HTTP_HOST',
                           os.environ['SERVER_NAME'])}
        dispatch = 'templates/georss.html'
        path = os.path.join(os.path.dirname(__file__), dispatch)
        output = template.render(path, template_values)
        self.response.headers['Cache-Control'] = 'public,max-age=%s' \
            % 86400
        self.response.headers['Content-Type'] = 'application/rss+xml'
        self.response.out.write(output)

I hope some of this works for you, both ways worked for me.