Using Custom Headers for Avatars

Some themes like to use the admin account’s avatar, if available, in the header of the theme to highlight the author. However, it’s nice to be able to change that image if the admin email’s avatar is not appropriate nor changeable.

The free Automattic theme Writr, by our very own Thomas Guillot, takes the approach of using Custom Headers for customizing the avatar image. In short, we’ll be using Custom Headers to output our image, and its default image argument will allow us to insert the avatar when no custom header image has been uploaded. Let’s get started!

In header.php, we output our Custom Header image as usual.

<!--?php 	$header_image = get_header_image(); 	if ( ! empty( $header_image ) ) : ?-->
	<a class="site-logo" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" href="<?php echo esc_url( home_url( '/' ) ); ?>" rel="home">
		<img class="no-grav header-image" alt="" src="<?php header_image(); ?>" width="<?php echo get_custom_header()->width; ?>" height="<?php echo get_custom_header()->height; ?>" />
	</a>
<!--?php endif; ?-->

While declaring support for Custom Headers, we set the default-image argument to be a function (which we’ll use for our avatar logic).

function writr_custom_header_setup() {
	add_theme_support( 'custom-header', apply_filters( 'writr_custom_header_args', array(
		'default-image'          => writr_get_default_header_image(),
		...
	) ) );
}
add_action( 'after_setup_theme', 'writr_custom_header_setup' );

Finally, our writr_get_default_header_image function fetches an image from the Gravatar service. If there’s no account matching the admin email sent, we can request another image to be returned from Gravatar; we’ll try to match it to the “Default Avatar” value in Settings → Discussion (that’s all that $default business). More detail on the arguments being sent can be found in the Gravatar Image Requests documentation.

function writr_get_default_header_image() {

	// Get default from Discussion Settings.
	$default = get_option( 'avatar_default', 'mystery' ); // Mystery man default
	if ( 'mystery' == $default )
		$default = 'mm';
	elseif ( 'gravatar_default' == $default )
		$default = '';

	$protocol = ( is_ssl() ) ? 'https://secure.' : 'http://';
	$url = sprintf( '%1$sgravatar.com/avatar/%2$s/', $protocol, md5( get_option( 'admin_email' ) ) );
	$url = add_query_arg( array(
		's' => 120,
		'd' => urlencode( $default ),
	), $url );

	return esc_url_raw( $url );
} // writr_get_default_header_image

That’s it; we automatically get the avatar of the admin email (or an appropriate substitute) from Gravatar, or we can simply upload a new custom header image to override it. Have fun!