add_filter( 'gform_pre_render_8', 'graduate_profile_populate' );
add_filter( 'gform_pre_submission_filter_8', 'graduate_profile_populate' );

function graduate_profile_populate( $form ) {
    // grab current user's information
    global $current_user;
    get_currentuserinfo();
    $user_login = $current_user->ID;

    // grab all entries from Membership form with #4
    $entries = RGFormsModel::get_leads( 4 );

    // find any submitted entries that belong to this user
    foreach( $entries as $entry ) {
        // $entry["created_by"] stores the Wordpress User ID of the user that submitted the form
        switch( $entry["created_by"] ) {
            case $user_login: // if our "created_by" ID matches our $user_login ID
                $lead_id = $entry["id"]; // store ID of this entry in $lead_id variable
                break;
            default:
                break;
        }
        //echo '<pre>'; print_r($entries); echo '</pre>';
    }

    // if $lead_id exists
    if( $lead_id ) {
        // get entry data by lead ID
        $entry = RGFormsModel::get_lead( $lead_id );

        foreach( $form["fields"] as &$field ) {
            switch( $field['type'] ) {
                case 'name':
                case 'address':
                    foreach( $field['inputs'] as &$input ) {
                        $field['allowsPrepopulate'] = true;
                        $parameter_name = strtolower( str_replace( ' ', '_', str_replace( '/ ', '', $input['label'] ) ) );

                        $input['name'] = $parameter_name;
                        $input_value = rgar( $entry, ( string ) $input['id'] );

                        add_filter( 'gform_field_value_' . $parameter_name, create_function( "", "return '$input_value';" ) );
                    }
                    break;

                case "day" :
                    return array(
                        "start_date" => gmdate( "Y-m-d" ),
                        "end_date" => gmdate( "Y-m-d" ) );
                    break;

                case "week" :
                    return array(
                        "start_date" => gmdate( "Y-m-d", strtotime( "last Monday" ) ),
                        "end_date" => gmdate( "Y-m-d", strtotime( "next Sunday" ) ) );
                    break;

                case "month" :
                    $month_start = gmdate( "Y-m-1" );
                    return array(
                        "start_date" => $month_start,
                        "end_date" => gmdate( "Y-m-d", strtotime( "{$month_start} +1 month - 1 hour" ) ) );
                    break;

                case "year" :
                    return array(
                        "start_date" => gmdate( "Y-1-1" ),
                        "end_date" => gmdate( "Y-12-31" ) );
                    break;

                default:
                    $field['defaultValue'] = $entry[$field['id']];
                    break;
            }
        }
    }
    return $form;
}