Adding categories to blog.

[guusdk]

Currently, all blog posts are in the same default category 'misc'. This PR adds some other categories.

Certain posts could go into two categories, but I've yet to figure out how that's done. Comma-separated won't work, nor will adding the header twice.

Feel free to improve or add to this.

[tfar]

Many constraints in pelican are by design, so is that a post can only be in one category, see getpelican/pelican#350 . It can have more than one tag though.

[guusdk]

Ah, ok. Should we move to tags then, or is a single category good enough?

[tfar]

I imagine there are use case for tags and categories. With tags you can have multiple and categories can build hierarchies I think. I'd go with only tags as we probably won't need a hierarchy in our blog posts and tags provide more flexibility.

[guusdk]

Meh. Not sure how to proceed. When I switch 'categorie' for 'tags', then nothing visually changes (as compared to before I started this PR). When I use 'tag' (instead of 'tags'), Pelican throws this error during page generation:

Traceback (most recent call last):
  File "/usr/local/bin/pelican", line 11, in <module>
    sys.exit(main())
  File "/usr/local/lib/python2.7/dist-packages/pelican/__init__.py", line 465, in main
    pelican.run()
  File "/usr/local/lib/python2.7/dist-packages/pelican/__init__.py", line 179, in run
    p.generate_output(writer)
  File "/usr/local/lib/python2.7/dist-packages/pelican/generators.py", line 599, in generate_output
    self.generate_feeds(writer)
  File "/usr/local/lib/python2.7/dist-packages/pelican/generators.py", line 300, in generate_feeds
    self.settings['FEED_ALL_ATOM'])
  File "/usr/local/lib/python2.7/dist-packages/pelican/writers.py", line 123, in write_feed
    self._add_item_to_the_feed(feed, elements[i])
  File "/usr/local/lib/python2.7/dist-packages/pelican/writers.py", line 49, in _add_item_to_the_feed
    link = '%s/%s' % (self.site_url, item.url)
  File "/usr/local/lib/python2.7/dist-packages/pelican/contents.py", line 326, in url
    return self.get_url_setting('url')
  File "/usr/local/lib/python2.7/dist-packages/pelican/contents.py", line 188, in get_url_setting
    return self._expand_settings(key)
  File "/usr/local/lib/python2.7/dist-packages/pelican/contents.py", line 182, in _expand_settings
    return self.settings[fq_key].format(**self.url_format)
  File "/usr/local/lib/python2.7/dist-packages/pelican/contents.py", line 175, in url_format
    'tag': self.tag.slug if hasattr(self, 'tag') else '',
AttributeError: 'unicode' object has no attribute 'slug'

[tfar]

tags was probably correct. However, our theme doesn't use tags yet in the UI. If you take a look at https://github.com/xsf/xmpp.org/blob/master/xmpp.org-theme/templates/article.html it only mentions category. So it seems using tags would require further adjustments to our theme. Happy to go with categories instead then.

[guusdk]

I tend to agree. Let's ping @bear (ping!) to see if switching from categories to tags in the theme is easy, but if not, let's go with categories.

[bear]

it doesn't really matter which is used as long as the code that generates the feeds is also updated

[guusdk]

Where is the code that updates the feed? Is that the same code as what @stpeter mentions is broken in xsf/xeps#1179 ?

[bear]

probably - it may end up just being a config issue

[guusdk]

After the merge, categories popped up, and the single blog feed that we already had did not break. I'm declaring this a success. ;)