Atom feed thumbnails

[maiki interi]

Not entirely on topic with #658 or #659, but related.

My expectation was for the atom feed to contain the thumbnail of the image (or equivalent of other media types). This is important to me, as I want to widgetize/aggregate the feed on other sites.

I found two places where feeds are generated, mediagoblin/user_pages/views.py and mediagoblin/listings/views.py:

for entry in cursor:
    feed.add(entry.get('title'),
        entry.get('description_html'),
        content_type='html',
        author=request.matchdict['user'],
        updated=entry.get('created'),
        url=entry.url_for_self(request.urlgen))

I am not sure what the thumbnail is, but I am betting it is a summary or maybe content (see the werkzeug atom docs). I think this is important, even if we are moving to make it a full ActivityStream, since the federation I have in mind is something akin to a dashboard view of new photos posted on my friends' sites.

So, can we get a thumbnail in there? =]

[Christopher Allan Webber]

Yes we certainly need a way to share this...

[Inconexo ø]

I have done a try. Not very happy because I had to:

1. Write html code inside python code. I don't feel that very orthodox.
2. Img comes inside html content. I don't know if there is a better way to include this, but I haven't found it inside the atom library documentation.

Please, tell me any comment that would improve my implementation.

git: [https://gitorious.org/_{inconexo/mediagoblin/inconexos-mediagoblin](https://gitorious.org/}inconexo/mediagoblin/inconexos-mediagoblin) branch: 676_feed_thumbs

[Christopher Allan Webber]

Hey Inconexo, thanks for the work on this. :)

I think the best route would be to actually shift over the work to making our own atom feed generator... I think we'll need to for #659 anyway. And this would avoid such grossness as we're extending that code.

Inconexo: if you're interested in pushing us toward a beautiful federated future, a good way to start might be to help write an atom feed generator using lxml :) http://lxml.de/tutorial.html

If you're interested in this, let me know! If you are interested but have no experience with lxml, read that tutorial and ping me on irc... you'll find it's pretty easy though, I think.

[Inconexo ø]

Well, finally, feed library is written. Please notice I am a beginner with Python. Please comment any problem and I will fix it.

I have kept two goals:

1. Same interface as Werkzeurg's. This way, changing one feed generator to other is changing the import.
2. Extensibility. I have made a generator class. If we wanted to generate RSS or other feed systems, we could write another generator, reusing a lot of code.

I have also added thumbnails capabilities. First, I added media:thumbnails elements, but it doesn't seem to work with firefox' and other's agregators. Any help with that is appreciated. So, I used the same old trick: including the thumbnail inside the content.

Anyway, you can take a look:

git: [https://gitorious.org/_{inconexo/mediagoblin/inconexos-mediagoblin](https://gitorious.org/}inconexo/mediagoblin/inconexos-mediagoblin) branch: feed_library

[Elrond]

Okay, this one diverged somewhat into "we need a feed library". And one was created. This is actually bug #711. So made this one block'd by 711.

When 711 is done, we should revisit this one.

[Will Kahn-Greene]

The original url for this bug was ​http://bugs.foocorp.net/issues/676 .
Relations:
#310: related, #311: related, #358: blocked

[spaetz]

To post media in the atom feed, we'll need to add something like:

<link rel="enclosure" type="image/jpeg" href="​http://farm9.staticflickr.com/8343/8187137313_2e211c431f_b.jpg" />

to the atom feed. At least this is what the flickr atom feed does.

[spaetz]

I pushed a Work-In-Progess branch 328_media_in_atom_feed to my repo at ​git://gitorious.org/~spaetz/mediagoblin/spaetz-mediagoblin.git

It does not implement a new Atom feed generator, but at least it embeds the posted media as a
<link href="....jpg" rel="enclosure"/> which is what the flickr atom feed also does to convey the posted media.

I stumbled upon 2 roadblocks while implementing: mg_globals.public_store.file_url(media_entry) returns a relativ URL without HOST and we need a real fully external URL there. How can we achieve that?

Second, how can I determine the media type of the media so that browsers detect it correctly? Right now I hardcoded 'type': 'image/jpeg' which is obviously bad.

[Will Kahn-Greene]

Given that this is about thumbnails and not enclosing the actual media item, it's not corrrect to use <link href="..." rel="enclosure"/>. That's for enclosing media items like for podcasts, picturecasts, etc. Flickr encloses the entire media item.

To have thumbnails, you should use the MRSS module:

​http://www.feedforall.com/mediarss.htm

Firefox feed preview shows enclosures, but not thumbnails (weirdly, I helped write that).

What YouTube does is create an HTML thingy with the thumbnail in that and put that in the description. I suggest you do something like that. That's very common with podcast-like feeds.