URL structure, was Re: Quick rants about your BTS

[Christian Robottom Reis]

On Tue, Mar 28, 2006 at 05:09:44PM +0900, Kai Hendry wrote:
> >   https://launchpad.net/products/malone/+filebug
>
> I wonder why on earth there is a + sign in the URL.

The URL structure in Launchpad follows some rules which are pretty
simple but perhaps obscure to most people:

    - A path component can have one or more literal components under it.
      Examples are:

        /products/+new
        /products/malone/+filebug
        /distros/ubuntu/+allpackages

      In the first example above, the string "+new" is attached to the
      /products component.

    - A path component can be "traversed" using a custom function which
      generally produces components based on data (I'm calling them
      "data URL components"). Examples are:

        /products/malone

            There is a traversal function attached to the component
            "/products"; the word "malone" identifies a product by its
            unique name.

        /distros/ubuntu

            There is a traversal function attached to the component
            "/distros"; the word "ubuntu" identifies a distribution by its
            unique name.

        /products/malone/+bugs/1

            There is a traversal function attached to the component
            "+bugs" (which itself is a literal component attached to the
            product "malone"); the value "1" identifies a bug by its
            unique ID.

The reason literal components have a plus is generally to disambiguate
the literal component in the URL from a "data URL component". For
instance, compare

    /products/+new

with

    /products/new

If we didn't use a plus to prefix the literal component, and someone
registered a product called "new", we'd have a pathname clash.

I don't like the plusses very much, myself, but I have grown used to
them. One alternative to them is blacklisting names (so creating a
product called "new" would be forbidden); that approach is not very
future-proof, however, and we haven't considered changing yet.

Note that we are not entirely consistent with the use of plusses when a
component has no data traversal under it; that's perhaps the reason why
we have launchpad.net/malone and launchpad.net/products but also
launchpad.net/+builds.
-- 
Christian Robottom Reis | http://async.com.br/~kiko/ | [+55 16] 3376 0125