I often click on a post's feed, so as to go to the post's site, just to make sure I'm not reading outdated information. Does Google Reader update the post's contents, so I don't have to keep doing this?
Simple answer is no.
More complex answer is...
As far as I know, Google Reader is only a RSS reader. A good one, but only a reader. If you don't know the RSS format (or Atom, for that purpose, there is no difference), just follow me a little.
A RSS file contains a list of dated events. Basically, in a feed, there are some infos for each event:
What Google Reader displays is the event text. And absolutely no source site text content. However, there are some cases where the source site can send new events when the content is modified. In such cases, Google Reader will display both events, with different text.
According to Tshepang
Not unless the URL back to the source has changed since Google Reader took its copy of the feed item.
When the RSS reader grabs a feed, it will be a copy of it as it was at that time. The only reason why a reader would download a new version of the post is if it detects a new feed item with a
But, it will only download a new copy and won't update an existing feed item.
This is why if your favourite blog moves domains you'll see a repeat of old posts turning up as "new" in your feedbox. That's because according to the URL of the posts and items, they are new. Even if it's the same body content.
Yes, Google Reader updates a post's content if it is modified though not immediately.
I have subscribed to my own blog's feed (hosted on Blogger) & whenever I update an older post with new info, the modified content appears in an hour or so.