NSXMLParser Simple Example

Question

Most of the examples of how to invoke the NSXMLParser are contained within complex projects involving Apps. What does a simple example that demonstrates the callbacks look l

Answer 1

#import 

@interface AppDelegate : NSObject 
@property (nonatomic, strong) NSMutableDictionary *dictXML;
@property (nonatomic,strong) NSMutableArray *arrOfUpdateDictsByVersion;
@property (nonatomic,strong) NSString *strElementBeingParsed;
@property (nonatomic,strong) NSString *strElementFinishedParsing;

@end


#import "AppDelegate.h"

@interface AppDelegate ()
@property (weak) IBOutlet NSWindow *window;
@end

@implementation AppDelegate

@synthesize dictXML;
@synthesize arrOfUpdateDictsByVersion;

@synthesize strElementBeingParsed;
@synthesize strElementFinishedParsing;


- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    // Insert code here to initialize your application

    [self initializeTheArray];
    [self startParsingXML];
}

-(void)initializeTheArray{
    self.dictXML = [[NSMutableDictionary alloc] init];
    self.arrOfUpdateDictsByVersion = [[NSMutableArray alloc] init];
}

-(void)startParsingXML{
//    NSXMLParser *xmlparser = [[NSXMLParser alloc] initWithContentsOfURL:[NSURL URLWithString:@"http://cdn.example.com/databaseupdate.xml"]];
    NSXMLParser *xmlparser = [[NSXMLParser alloc] initWithContentsOfURL:[NSURL fileURLWithPath:@"/Users/vkrmsinha/Desktop/xmlParse.xml"]];
    [xmlparser setDelegate:self];
    [xmlparser parse];
}

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict;
{
    // initial tag comes in here
    self.strElementBeingParsed = elementName;
    /*if([elementName isEqualToString:@"Version"]){

    }
    else if ([elementName isEqualToString:@"Update"]){

    }*/
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string;
{

    if(([string rangeOfCharacterFromSet:[NSCharacterSet newlineCharacterSet]].location != NSNotFound) && ![self.strElementBeingParsed isEqualToString:@"Update"])
        return;

    // middle part from between the start and end tags comes here
    if ([self.strElementBeingParsed isEqualToString:@"Update"]){
        NSMutableDictionary *dictUpdate = [NSMutableDictionary dictionary];
        [self.arrOfUpdateDictsByVersion addObject:dictUpdate];
    }
    else if ([self.strElementBeingParsed isEqualToString:@"UpdateType"]){
        NSMutableDictionary *dictUpdate = [self.arrOfUpdateDictsByVersion lastObject];
        NSMutableDictionary *dictUpd = [NSMutableDictionary dictionary];
        [dictUpd setValue:string forKey:@"UpdateType"];
        [dictUpdate setValue:dictUpd forKey:@"update"];
    }
    else if([self.strElementBeingParsed isEqualToString:@"Version"]){
        NSMutableDictionary *dictUpdate = [self.arrOfUpdateDictsByVersion lastObject];
        // WARNING: ASK IF NO TWO VERSION WILL BE SAME IN FUTURE
        [dictUpdate setValue:string forKey:@"version"];
    }
    else if ([self.strElementBeingParsed isEqualToString:@"FileName"]){
        NSMutableDictionary *dictUpdate = [self.arrOfUpdateDictsByVersion lastObject];
        NSMutableDictionary *dict = [dictUpdate objectForKey:@"update"];
        [dict setValue:string forKey:@"FileName"];
    }
    else if ([self.strElementBeingParsed isEqualToString:@"Hash"]){
        NSMutableDictionary *dictUpdate = [self.arrOfUpdateDictsByVersion lastObject];
        NSMutableDictionary *dict = [dictUpdate objectForKey:@"update"];
        [dict setValue:string forKey:@"Hash"];
    }
    else if ([self.strElementBeingParsed isEqualToString:@"DownloadURL"]){
        NSMutableDictionary *dictUpdate = [self.arrOfUpdateDictsByVersion lastObject];
        NSMutableDictionary *dict = [dictUpdate objectForKey:@"update"];
        [dict setValue:string forKey:@"DownloadURL"];
    }
    else if ([self.strElementBeingParsed isEqualToString:@"Size"]){
        NSMutableDictionary *dictUpdate = [self.arrOfUpdateDictsByVersion lastObject];
        NSMutableDictionary *dict = [dictUpdate objectForKey:@"update"];
        [dict setValue:string forKey:@"Size"];
    }

}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName;
{
    // ending of tag comes in here
    self.strElementFinishedParsing = elementName;
    if([elementName isEqualToString:@"Update"]){
        [self.arrOfUpdateDictsByVersion sortUsingDescriptors:[NSArray arrayWithObjects:[NSSortDescriptor sortDescriptorWithKey:@"self.version" ascending:YES], nil]];
        NSLog(@"%@", [self.arrOfUpdateDictsByVersion lastObject]);

    }
    if([elementName isEqualToString:@"UpdateDetails"]){
        NSMutableDictionary *dict = [NSMutableDictionary dictionary];
        [dict setValue:[[self.arrOfUpdateDictsByVersion lastObject] objectForKey:@"version"] forKey:@"latestVer"];
        [dict setValue:[[self.arrOfUpdateDictsByVersion firstObject] objectForKey:@"version"] forKey:@"oldestVer"];
        [dict setValue:self.arrOfUpdateDictsByVersion forKey:@"arrOfUpdsByVer"];
        NSLog(@"%@", dict);
    }

}

- (void)applicationWillTerminate:(NSNotification *)aNotification {
    // Insert code here to tear down your application
}



   
    
     CompleteDatabase
     1
     1completedatabase.zip
     ad94431d2fe4cd60eb3347fadaa45d88
     
      http://www.example.com/download/new.xml
     
     2367008