New Default

After over 8 hours of research and trial-and-error, I’ve devised a pseudo-way of achieving this:

add_filter( 'shortcode_atts_wpcf7', 'custom_shortcode_atts_wpcf7_filter', 10, 3 );
function custom_shortcode_atts_wpcf7_filter( $out, $pairs, $atts ) {
        $my_attr = 'your-message';
        $user_id = get_current_user_id();
        if ( isset( $atts[$my_attr] ) and $user_id != 0 ) {
                $description = get_user_meta( $user_id , 'description', true );
                $out[$my_attr] = $description;
        } 
        return $out;
}

This filter allows me to set the default from the user’s bio (description), as long as I add the attribute to the shortcode and set the form’s field to default to it.

In this snippet, it doesn’t matter what the attr ‘your-message’ is set to in the shortcode – in the form, it will default to the user’s description regardless of the attribute’s content, as long as the attribute is set.

If you want to adapt this code to your own form, change $my_attr to the name of the field you want to default, add default:shortcode_attr to the field in the form editor and add whatever you set $my_attr to into the end of the shortcode on your page.

Hope someone else finds this useful to justify my 8+ hours of suffering ??