Get at tags for blog posts programmatically

Question

I wonder how to get at tags in blog posts (WordPress, Blogger, or Blogspot) programmatically (API, RSS feed, XML, other methods). Preferably a solution usable in Ruby on Rails.

Answer 1

If either of those have an API, i'd start by reading their documentation; outside of that; you can roll your own screenscraper (which is likely to be useless, given the amount of DOM content that is script generated these days)

Wordpress API

Blogger API

Answer 2

See what the life streaming Rails apps such as kakuteru are using. Tagging across multiple Web2.0 style streams is important to kakuteru and I think they may employ a number of techniques. The also employ zemanta which has an API to generate tags from content. You can see zemanta's example of getting tags using ruby