Support empty hashes in rewrite rules (or forcedefault option)

[François Marier]

In order to avoid having to hardcode an "unknown" email address into client code, it would be good if the following were to always return the default image:

  http://cdn.libravatar.org/avatar/

(which it currently does) but also parse the size and default parameters so that we can use this URL to output a 128x128 image for example:

  http://cdn.libravatar.org/avatar/?s=128

or this one to output a 128x128 "mystery man"

  http://cdn.libravatar.org/avatar/?s=128&d=mm

Gravatar does support this:

  http://www.gravatar.com/avatar/?s=128&d=mm
  http://www.gravatar.com/avatar/?s=128&d=mm

Note that it does NOT need to redirect to Gravatar since the image will not be there either.

Fixing this will make changes like these unnecessary:

  https://github.com/fmarier/libravatar-wordpress/commit/283be47fd654f6b5edd27b056d66d3cb0a7010fe

[François Marier (fmarier)]

We should also support the "force default" (f=y) option:

  http://en.gravatar.com/site/implement/images/#force-default

[James Dearing (dearingj)]

There are two uses I can think of for this:

1) To demo different settings. I'm currently writing a WordPress plugin to make it use Libravatar (I know there's one out there already, but I decided to write my own) and Libravatar not supporting the forcedefault option makes it look like my plugin doesn't work right, because the settings page shows all the same avatars.

2) Hypothetically, some site administrators might decide they like the generated avatars, and so don't want to allow non-generated ones. If they switch to Libravatar, any page that displays user avatars would be messed up because Libravatar provides the "wrong" pictures.

So yeah, it's not exactly the most important feature, but it is expected functionality if people are going to replace Gravatar.

On a side note, if forcedefault does get implemented: WordPress currently uses "forcedefault=1" rather than "forcedefault=y". So consider allowing both 1 and y.