Use gform_pre_render / Google distance Matrix to calculate distance on page 2 of form based on input on page1

Ok so now im as far as to getting “meters” returned after customer filled in street/city in page 1 of the form.

Only thing is i only manage to get the result into an “html-block” with code underneath (by now plugin). I would like to get the result into the quantity field of a product, but parsing result to “value” of relevant field id doenst seem to work.

example:
terramilieu.nl/test

My code:

function getDrivingDistance($startstreet, $startcity, $endstreet, $endcity)
{
    $url = "https://maps.googleapis.com/maps/api/distancematrix/json?origins=".urlencode($startstreet)."+".urlencode($startcity)."&destinations=".urlencode($endstreet)."+".urlencode($endcity)."&mode=driving&key=AIzaSyDtNDZRDEy2b8FLchNY4I2Okl1sLlFEIDw";
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_PROXYPORT, 3128);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
    $response = curl_exec($ch);
    curl_close($ch);
    //$response_a = json_decode($response, true);
    $json = file_get_contents($url); // get the data from Google Maps API
    $result = json_decode($json, true); // convert it from JSON to php array

    $dist = $result['rows'][0]['elements'][0]['distance']['text'];
    $meters = $result['rows'][0]['elements'][0]['distance']['value'];
    $time = $result['rows'][0]['elements'][0]['duration']['text'];

    return array('distance' => $dist, 'meters'=> $meters, 'time' => $time);
}


function gdmDist($street, $city){
    $result = getDrivingDistance('Industrieweg 16', 'Vught', $street, $city);

    return ($result['meters']);
}


add_filter( 'gform_pre_render_6', 'populate_html' ); 

    function populate_html( $form ) {
    //this is a 2-page form with the data from page one being displayed in an html field on page 2
    $current_page =GFFormDisplay::get_current_page( $form['id'] );

    if ( $current_page == 2 ) {
        foreach ( $form['fields'] as &$field ) {
            //gather form data to save into html field (id 6 on my form), exclude page break
            $field_data = rgpost('input_' . $field->id );
            if ( $field->id == 49 && $field->type != 'page' ) 
                {                                        
                    $html_content_49 = $field_data;                                        
                }            
            elseif ( $field->id == 50 ) 
            {         
                    $html_content_50 = $field_data;                               
            }            
        }                                   
        //loop back through form fields to get html fields that we are populating with the data gathered above
        foreach( $form['fields'] as &$field ) {
            //get html field
            if ( $field->id == 51 ) {
                //set the field content to the html
                $field->content = $html_content_49;
            }              
            if ( $field->id == 58 ) {
                //set the field content to the html
                $field->content = $html_content_50;
            } 
            if ( $field->id == 60 ) {
                $fieldval_address =  $html_content_49;
                $fieldval_city = $html_content_50;
                $result_end = getDrivingDistance('Industrieweg 16', 'Vught', $fieldval_address, $fieldval_city);                    
                //$result = gdmDist($fieldval_address, $fieldval_city);                    
                //set the field content to the html                
                $field->content = $result_end['meters'];                
            }             
        }  
    }
    //return altered form so changes are displayed
    return $form;
}