Question

I am working on a chrome bookmarking extension with google app engine as the backend. I am the only user now but I thought that if in the future there are other users the url needs to include the user name for the extension to interact with the backend. So I was thinking to change

http://ting-1.appspot.com/useradminpage

to

http://ting-1.appspot.com/user_name/useradminpage

where “user_name” is the gmail user id.

But I looked at twitter url and I see that they have

http://twitter.com/#!/user_name/

What is the purpose of “#!”? Is my scheme good enough in this case?

Answer 1

The # in a URL signifies the ‘fragment identifier’. Historically this has been used to identify a part of a document identified by an ‘anchor’ tag, but recently webapp developers have begun to use it to pass information about the page state to Javascript code running in the page. This is used because it’s possible for Javascript code to modify the fragment of the current page without causing the page to reload – meaning it can update as you browse through the webapp, and go right back to where you were when you reload the page.

The fragment is not sent to the server when the browser loads a page, so Twitter’s server just sees a request for twitter.com; it’s up to the Javascript code in the page to examine the fragment and determine what to do after that.

In your particular case, assuming you’re using the App Engine User service to authenticate users, you have a number of options for how to distinguish users in your URLs:

1. Use their email address. In theory this can change, and users may not want their address in a URL they will share. If the URLs are private, this is more or less a moot point.
2. Use their user_id. This is opaque and reveals no useful information about the user, so it’s safe, but it’s also meaningless and hard to remember.
3. Let users pick a nickname for their URLs, like Facebook and other services do, on a first-in, first-served basis.