Xml使用NSURL委託方法解析

Question

請建議我使用連接方法進行xml解析的好鏈接。

爲什麼需要連接方法？

這裏我遇到了擴展類的教程？

我不明白爲什麼需要延長它？ 給我一些很好的例子，它做的XML與連接

#import "WebRequestAPI.h" 

@interface NSObject(Extended) 
-(void)setData:(NSString *)message items:(NSMutableArray *)items withtag:(int)tag; 
@end 

@interface ConnectionClass:NSObject{ 
NSMutableData *receivedData; 
NSString *className; 
NSString *rootName; 
NSObject *m_delegate; 
int tag; 
} 
-(id)initWithClass:(NSString *)class withRoot:(NSString *)root withDelegate:(NSObject *)delegate withTag:(int)t; 
@end 

@implementation ConnectionClass 
-(id)initWithClass:(NSString *)class withRoot:(NSString *)root withDelegate:(NSObject *)delegate withTag:(int)t 
{ 
    m_delegate = delegate; 
    className = class; 
    rootName = root; 
    tag=t; 
    return self; 
} 
- (void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data { 
    if (receivedData != nil) { 
     [receivedData appendData:data]; 
    } else { 
     receivedData = [[NSMutableData alloc] initWithData:data]; 
    } 
} 

- (void)connectionDidFinishLoading:(NSURLConnection *)connection { 

    if([className length]==0) { 
     NSMutableArray *item = [[NSMutableArray alloc]  initWithObjects:rootName,receivedData,nil]; 
     [m_delegate setData:@"" items:item withtag:tag]; 
     [item release]; 
    } 
    else { 

     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; 
     NSString *strData = [[NSString alloc] initWithBytes:[receivedData bytes] 
                length:[receivedData length] encoding: NSUTF8StringEncoding]; 
     NSData *data = [strData dataUsingEncoding:NSUTF8StringEncoding]; 
     XMLParser *xmlParser = [[XMLParser alloc] initWithData:data]; 
     [xmlParser setClassName:className withRootName:rootName]; 
     [xmlParser setDelegate:xmlParser]; 
     [xmlParser setShouldProcessNamespaces:NO]; 
     [xmlParser setShouldReportNamespacePrefixes:NO]; 
     [xmlParser setShouldResolveExternalEntities:NO]; 
     [xmlParser parse]; 
     [m_delegate setData:xmlParser.message items:xmlParser.items withtag:tag]; 
     [xmlParser release]; 
     [strData release]; 
     [pool release]; 
    } 
} 

-(void)dealloc { 
    [receivedData release]; 
    [super dealloc]; 
} 
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error 
{ 
     [m_delegate setData:@"Connection required." items:nil withtag:0]; 
} 

@end 

@implementation WebRequestAPI 

-(id) init { 

     return self; 
    } 

    #pragma mark - demoAPI. 
    + (void)demoApi:(NSObject *)delegate 
    { 
      int tag = 1; 
      NSString *demoStr = [NSString stringWithFormat:@"http://www.astrology.com/horoscopes/daily-horoscope.rss"]; 
      demoStr = [demoStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; // NSASCIIStringEncoding]; 

      NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:demoStr] 
                  cachePolicy:NSURLRequestReloadIgnoringCacheData               timeoutInterval:60.0]; 

      ConnectionClass *con = [[[ConnectionClass alloc]initWithClass:@"item" withRoot:@"" withDelegate:delegate withTag:tag]autorelease]; 

      [[[NSURLConnection alloc]initWithRequest:theRequest delegate:con] autorelease]; 
} 

@end 

Answer 1

http://www.sitepoint.com/parsing-xml-files-with-objective-c/

u能看看這個解析。我覺得很好理解basics.Rest在烏爾手:)

在我viewcontroller.m

- (void)xmBtnTouched:(id)sender { 
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:[NSURL URLWithString:@"http://www.w3schools.com/xml/cd_catalog.xml"] cachePolicy:NSURLCacheStorageAllowed timeoutInterval:120.0f]; 
    NSLog(@"request is %@",request); 
    NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self startImmediately:YES]; 

} 
/*******************************************************************************/ 
#pragma mark - connection delegates 

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response 
{ 
    [receivedData setLength:0]; 
} 

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data 
{ 
    [receivedData appendData:data]; 
    NSLog(@"received Data is %@",receivedData); 

} 
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error 
{ 

} 

- (void)connectionDidFinishLoading:(NSURLConnection *)connection 
{ 
    NSLog(@"Received data in finsh loading are %@",receivedData); 
    receivedString = [[NSMutableString alloc]initWithData:receivedData encoding:NSASCIIStringEncoding]; 
    NSLog(@"received string is %@",receivedString); 


    // setting tghe parser and common class for parser 
    xmlParser = [[NSXMLParser alloc]initWithData:receivedData]; 
    parser = [[catalogParser alloc]init]; 
    [parser setStringInXml:receivedString]; 
    [parser setDelegate:self]; 
    [xmlParser setDelegate:parser]; 
    [xmlParser parse]; 


} 

xmlparser.m

#import "catalogParser.h" 

@implementation catalogParser 
@synthesize stringInXml; 
@synthesize catalogString; 
@synthesize catalogArray; 
@synthesize delegate; 

- (id)initWithData:(NSData *)parseData { 

    self = [super init]; 

    if (self) { 



    } 

    return self; 

} 
/**************************************************************************************/ 

#pragma mark - Xml parser delegates 

- (void)parserDidStartDocument:(NSXMLParser *)parser 
{ 
    NSLog(@"string i s%@",stringInXml); 
    catalogArray = [[NSMutableArray alloc]init]; 
} 
- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict 
{ 
    if ([elementName isEqualToString:@"CATALOG"]) { 



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

     catalogObject = [[Catalog alloc]init]; 
    } 

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

    NSLog(@"string is ********** %@",string); 
    if(!catalogString) 
    { 
    catalogString = [[NSMutableString alloc]init]; 
    } 

    catalogString = (NSMutableString *) [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; 

} 
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName 
{ 
// if ([elementName isEqualToString:@"CATALOG"]) { 
//  return; 
// } 
    if ([elementName isEqualToString:@"TITLE"]) { 
     catalogObject.title = catalogString; 
    } 
    else if ([elementName isEqualToString:@"ARTIST"]) 
    { 
     catalogObject.artist = catalogString; 
    } 
    else if ([elementName isEqualToString:@"COUNTRY"]) 
    { 
     catalogObject.country = catalogString; 
    } 
    else if ([elementName isEqualToString:@"COMPANY"]) 
    { 
     catalogObject.company = catalogString; 
    } 
    else if ([elementName isEqualToString:@"PRICE"]) 
    { 
     catalogObject.price = catalogString; 
    } 
    else if ([elementName isEqualToString:@"YEAR"]) 
    { 
     catalogObject.year = catalogString; 
    } 
else if ([elementName isEqualToString:@"CD"]) 
{ 
    [catalogArray addObject:catalogObject]; 
    [catalogObject release]; 
    catalogObject = nil; 
    [catalogString release]; 
    catalogString = nil; 
} 


} 
// sent when the parser begins parsing of the document. 
- (void)parserDidEndDocument:(NSXMLParser *)parser 
{ 

    [self.delegate parsingComplete:catalogArray]; 

} 

模態類catalog.h

#import <Foundation/Foundation.h> 

@interface Catalog : NSObject 
@property(retain,nonatomic)NSString *title; 
@property(retain,nonatomic)NSString *artist; 
@property(retain,nonatomic)NSString *country; 
@property(retain,nonatomic)NSString *company; 
@property(retain,nonatomic)NSString *price; 
@property(retain,nonatomic)NSString *year; 

@end 

在我的viewcontroller.m 我有一個按鈕，當觸摸將調用連接代表，然後獲取數據，然後將其傳遞給xmlparser.m，其中我將相應的數據存儲在模態類委託中，然後使用自定義委託將此數據傳回給視圖控制器