<?xml version="1.0"?>
<Mytrip>
    <start_time>06/06/2013 09:00:00 AM</start_time>
    <end_time>06/06/2013 09:30:00 AM</end_time>
    <start_address> 12 NGO, Roseville, Mp</start_address>
    <start_gps>+40.689060,-74.044636</start_gps>
    <end_address>8 STE stree, Roseville, MP</end_address>
    <end_gps>+42.689060, -72.044636</end_gps>
    <duration>00:00:00:00</duration>
    <label>Roseville Trip</label>
    <route>
        <point>
            <gps>+40.689060,-74.044636</gps>
            <speed>1.2 Miles/Hr</speed>
        </point>
        <point>
            <gps>+41.689060,-74.044636</gps>
            <speed>5.0 Miles/Hr</speed>
        </point>
   </route>
</Mytrip>

@interface Trip : NSObject

@property (nonatomic, copy) NSString *label;

@property (nonatomic, copy) NSString *start_address;
@property (nonatomic, copy) NSString *end_address;

@property (nonatomic, copy) NSString *start_time;
@property (nonatomic, copy) NSString *end_time;

@property (nonatomic, copy) NSString *start_gps;
@property (nonatomic, copy) NSString *end_gps;

@property (nonatomic, copy) NSString *duration;

@property (nonatomic, strong) NSArray *points;

- (GDataXMLElement *)XMLNode;
- (NSString *)XMLString;

@implementation Trip

- (GDataXMLElement *)XMLNode{

    GDataXMLElement *tripNode = [GDataXMLElement elementWithName:@"Mytrip"];

    GDataXMLElement *startTimeElement = [GDataXMLElement elementWithName:@"start_time" stringValue:self.start_time];
    [tripNode addChild:startTimeElement];
    GDataXMLElement *endTimeElement = [GDataXMLElement elementWithName:@"end_time" stringValue:self.end_time];
    [tripNode addChild:endTimeElement];

    GDataXMLElement *startAddressElement = [GDataXMLElement elementWithName:@"start_address" stringValue:self.start_address];
    [tripNode addChild:startAddressElement];
    GDataXMLElement *endAddressElement = [GDataXMLElement elementWithName:@"end_address" stringValue:self.end_address];
    [tripNode addChild:endAddressElement];

    GDataXMLElement *startGpsElement = [GDataXMLElement elementWithName:@"start_gps" stringValue:self.start_gps];
    [tripNode addChild:startGpsElement];
    GDataXMLElement *endGpsElement = [GDataXMLElement elementWithName:@"end_gps" stringValue:self.end_gps];
    [tripNode addChild:endGpsElement];

    GDataXMLElement *durationElement = [GDataXMLElement elementWithName:@"duration" stringValue:self.duration];
    [tripNode addChild:durationElement];

    GDataXMLElement *labelElement = [GDataXMLElement elementWithName:@"label" stringValue:self.label];
    [tripNode addChild:labelElement];

    GDataXMLElement *routeNode = [GDataXMLElement elementWithName:@"route"];

    for (RoutePoint *point in self.points) {
        GDataXMLElement *pointNode = [point XMLNode];
        [routeNode addChild:pointNode];
    }

    [tripNode addChild:routeNode];

    return tripNode;
}

- (NSString *)XMLString{
    return [[self XMLNode] XMLString];
}

@interface RoutePoint : NSObject

@property (nonatomic, strong) NSString *gps;
@property (nonatomic, copy) NSString *speed;

- (GDataXMLElement *)XMLNode;
- (NSString *)XMLString;

@implementation RoutePoint

- (GDataXMLElement *)XMLNode{

    GDataXMLElement *pointNode = [GDataXMLElement elementWithName:@"point"];

    GDataXMLElement *gpsElement = [GDataXMLElement elementWithName:@"gps" stringValue:self.gps];
    GDataXMLElement *speedElement = [GDataXMLElement elementWithName:@"speed" stringValue:self.speed];

    [pointNode addChild:gpsElement];
    [pointNode addChild:speedElement];

    return pointNode;
}

- (NSString *)XMLString{
    return [[self XMLNode] XMLString];
}

Trip *trip = [Trip new];

trip.start_time = @"06/06/2013 09:00:00 AM";
trip.end_time = @"06/06/2013 09:30:00 AM";

trip.start_address = @"12 NGO, Roseville, Mp";
trip.end_address = @"8 STE stree, Roseville, MP";

trip.start_gps = @"+40.689060,-74.044636";
trip.end_gps = @"+42.689060, -72.044636";

trip.duration = @"00:00:00:00";
trip.label = @"Roseville Trip";

RoutePoint *point = [RoutePoint new];
point.gps = @"+40.689060,-74.044636";
point.speed = @"1.2 Miles/Hr";

trip.points = @[point];

NSLog(@"%@",[trip XMLString]);

NSMutableString *XMLString = [[NSMutableString alloc] init];
[XMLString appendString:@"<?xml version="1.0"?> n"];
[XMLString appendString:@"<scene> n"];
//... etc..