Fix ‘ID “email” already defined’ validation error using Sociable plugin for WordPress

The Sociable plug-in for WordPress can cause a W3C validation conflict because both the plug-in’s e-mail button and the WordPress comment form’s e-mail field have the ID “email.” Here’s how to fix it.

Sociable is a great plug-in that adds buttons at the bottom of your posts for readers to print, e-mail or share the posts on social networking sites.

If you use Sociable’s “E-mail this story to a friend!” button, you may get a validation error, “ID ‘email’ already defined,” if the blog post also has the WordPress comment form showing.

This is because both Sociable’s e-mail button and the comment form’s e-mail field use the same ID: “email.”

The fix is easy. Open up sociable.php and find the following section (it’s right after a comment that begins “Start building the link …”):


$link .= '<a rel="nofollow"';
$link .= ' id="'.esc_attr(strtolower($sitename)).'"';
if (get_option('sociable_usetargetblank')) {
$link .= " target=\"_blank\"";
}
$link .= " href=\"javascript:window.location='".urlencode($url)."';\" title=\"$description\">";

Immediately before this section, add the following:

if ($sitename=='email') {
$sitename .= '-sociable';
}

This will add “-sociable” to the ID of the Sociable e-mail button, making it “email-sociable” instead of simply “email.” Because the name is different, there will be no more “ID ‘email’ already defined” validation error.