Avatars

An avatar is the small round picture beside an account’s name. The avatar package builds its address on the server, so every screen draws the same avatar for the same account. It uses the standard library alone and reads no setting. Your application reads its own avatar settings and passes them in:

options := avatar.Options{Mode: mode, Default: image, Rating: rating}
src := avatar.Address(user.Name, user.Email, 48, options)

Put the address in the src of an <img>. An empty address means no avatar.

The three modes

• initials, the default, draws a circle with the first letter of the name in capitals. The picture is held inside the address itself (a data: address of an SVG drawing), so nothing leaves your application. It uses the six colours of godmin’s InitialsAvatar, picked from the name the same way.
• gravatar asks Gravatar for the picture the account’s owner uploaded there. The address carries the SHA-256 hash of the email, never the email itself.
• off draws nothing, and the address is empty.

Gravatar settings

They copy the Avatars section of the WordPress Discussion screen. The default image is what Gravatar shows for an email with no picture: mystery (the default), blank, gravatar_default (the Gravatar logo), identicon, wavatar, monsterid, retro, robohash, initials or color. With initials, the address also carries up to two letters of the name, as WordPress sends them. The rating is the most mature picture an avatar may show: G (the default), PG, R or X.

Reading settings

ParseMode, ParseDefault and ParseRating turn a stored setting into an option. An empty setting gives the default, and a value they do not know is refused with an error that names it. ParseSize reads a size from a request. It keeps 1 to 2048 pixels, Gravatar’s own limit, and gives 96 for an empty value, as WordPress does. Address brings any other size to the nearest bound.