Dynamically populate drop down in Gravity Forms with list of users with author role

gistfile1.txt

//replace 72 below with your form id number

add_filter( 'gform_pre_render_72', 'populate_posts' );
add_filter( 'gform_pre_validation_72', 'populate_posts' );
add_filter( 'gform_pre_submission_filter_72', 'populate_posts' );
add_filter( 'gform_admin_pre_render_72', 'populate_posts' );


function populate_posts( $form ) {

    foreach ( $form['fields'] as &$field ) {

        if ( $field->type != 'select' || strpos( $field->cssClass, 'populate-posts' ) === false ) {
            continue;
        }

        // You can change authors to another role. You'd change that here
        $users = get_users( 'role=author' );

        $choices = array();

        foreach ( $users as $user ) {
            $choices[] = array( 'text' => $user->display_name, 'value' => $user->display_name );
        }

        // update 'Select a Post' to whatever you'd like the instructive option to be
        $field->placeholder = 'Select a sales rep';
        $field->choices = $choices;

    }

    return $form;
}