重力表单，如何动态填充多列列表（选择为列）

I believe with this snippet, one shall be able to populate a field in wordpress gravity forms:

add_filter( "gform_field_value_products", "mu_populate_products" );
function mu_populate_products() {
    global $currUserEntry;
    if($currUserEntry){
        $e = rgar( $currUserEntry, '37' );
        alertUser(maybe_unserialize($e));
        return $e; 
    }
}

I can assure you that $e contains exactly the data which has been sent after validation of the form to the database, and the 37 and products are what they should be, I think the problem is that this products field is a list with two columns and the first column is concerted to <select> by this snippet:

add_filter( 'gform_column_input_30_37_1', 'set_column', 10, 5 );
function set_column( $input_info, $field, $column, $value, $form_id ) {
    return array( 'type' => 'select', 'choices' => 'choice 1, choice 2' );
}

any help would be appreciated

Well after a while here is the answer, for googlers perhaps,

function mu_populate_products() {
    global $currUserEntry;
    if($currUserEntry){
        $e = rgar( $currUserEntry, '37' );
        return maybe_unserialize($e); 
    }
}

all the point is that the function must return a deserialized object, while the rgar which returns the field value from db is serialized, so using maybe_unserialize was the key.

also bear in mind that this works since Gravity Forms 1.9.10.8 for more info: https://www.gravityhelp.com/documentation/article/gform_field_value_parameter_name/#3-list-field