Calling NSXMLParser from static method does not parse - ios

Question

I'm trying to build a nice little class with NSXMLParser for my needs.
I'm calling the class this way:
ViewController.m:
[IDAN_XML_Parser setXmlString:soapMsg];
[IDAN_XML_Parser setStringToFind:#"userID"];
[IDAN_XML_Parser setHeader:kAPP_PASSWORD andHeaderValue:kAPP_HEADER];
[IDAN_XML_Parser setSetupXml:kWEB_SERVICE_URL];
[IDAN_XML_Parser prepareParsingAndGetResponse];
NSString *answer = [IDAN_XML_Parser getResponse];
NSLog(#"Response: %#", answer);
And my class is this:
.h file:
#import <Foundation/Foundation.h>
#interface IDAN_XML_Parser : NSObject <NSXMLParserDelegate, NSURLConnectionDelegate>
+ (void)setXmlString:(NSString *)theXML;
+ (void)setStringToFind:(NSString *)stringToFind;
+ (void)setSetupXml:(NSString *)webServicesURL;
+ (void)setHeader:(NSString *)headerKey andHeaderValue:(NSString *)headerValue;
+ (BOOL)prepareParsingAndGetResponse;
- (NSInteger)startParsing;
+ (BOOL)isParsingOK;
+ (IDAN_XML_Parser *)sharedXML;
+ (NSString *)getXMLString;
+ (NSString *)getResponse;
#end
.m file
#import "IDAN_XML_Parser.h"
#implementation IDAN_XML_Parser
NSString *matchingElement;
NSString *xmlString;
NSMutableData *webData;
NSURLConnection *conn;
NSString *soapHeader_key;
NSString *soapHeader_value;
NSURL *url;
BOOL isHeader = NO;
NSInteger didGetError = 0;
BOOL elementFound;
NSMutableString *soapResults;
NSString *returnedString;
NSXMLParser *xmlParser;
NSString *exceptionReason;
NSString *resultXML;
#pragma mark - Setup Parsing
+ (IDAN_XML_Parser *)sharedXML
{
static IDAN_XML_Parser *theParser;
#synchronized(self) {
if (!theParser)
theParser = [[self alloc] init];
}
return theParser;
}
+ (void)setXmlString:(NSString *)theXML
{
xmlString = theXML;
NSLog(#"\n\nXML TO SEND: %#", xmlString);
}
+ (void)setStringToFind:(NSString *)stringToFind
{
matchingElement = stringToFind;
}
+ (void)setHeader:(NSString *)headerKey andHeaderValue:(NSString *)headerValue
{
isHeader = YES;
soapHeader_key = headerKey;
soapHeader_value = headerValue;
}
+ (void)setSetupXml:(NSString *)webServicesURL
{
url = [NSURL URLWithString:webServicesURL];
NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:url];
NSString *msgLength = [NSString stringWithFormat:#"%d", [xmlString length]];
[req addValue:#"text/xml; charset=utf-8" forHTTPHeaderField:#"Content-Type"];
[req addValue:msgLength forHTTPHeaderField:#"Content-Length"];
[req setHTTPMethod:#"POST"];
[req setHTTPBody: [xmlString dataUsingEncoding:NSUTF8StringEncoding]];
if (isHeader) {
[req setValue:soapHeader_value forHTTPHeaderField:soapHeader_key];
}
conn = [[NSURLConnection alloc] initWithRequest:req delegate:self];
if (conn)
{
webData = [NSMutableData data];
}
}
-(void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *) response
{
[webData setLength: 0];
}
-(void) connection:(NSURLConnection *)connection didReceiveData:(NSData *) data
{
[webData appendData:data];
}
-(void) connection:(NSURLConnection *)connection didFailWithError:(NSError *) error
{
didGetError = 1;
NSLog(#"\n\nConnection Error: %#", error);
}
-(void) connectionDidFinishLoading:(NSURLConnection *) connection
{
resultXML = [[NSString alloc] initWithBytes:[webData mutableBytes]
length:[webData length]
encoding:NSUTF8StringEncoding];
didGetError = 0;
NSLog(#"\n\nRESPONSE XML: %#", resultXML);
}
+ (BOOL)prepareParsingAndGetResponse
{
NSInteger isParsingOK;
isParsingOK = [[self sharedXML] startParsing];
if (isParsingOK == 1) {
return YES;
} else {
return NO;
}
}
- (NSInteger)startParsing
{
#try {
xmlParser = [[NSXMLParser alloc] initWithData:webData];
[xmlParser setDelegate:self];
[xmlParser setShouldResolveExternalEntities:YES];
[xmlParser parse];
}
#catch (NSException *exception) {
didGetError = 1;
exceptionReason = exception.reason;
NSLog(#"Exception Reason: %#", exception.reason);
}
if (didGetError != 1) {
didGetError = 0;
}
return didGetError;
}
+ (NSString *)getXMLString
{
return resultXML;
}
+ (BOOL)isParsingOK
{
if (didGetError == 1) { // We have error
return 1;
} else { // We don't have error
return 0;
}
}
+ (NSString *)getResponse
{
return returnedString;
}
#pragma mark - Start Parsing
- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
NSLog(#"START PARSING!");
if ([elementName isEqualToString:matchingElement]) {
if (!soapResults) {
soapResults = [[NSMutableString alloc] init];
}
elementFound = YES;
}
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
if (elementFound) {
[soapResults appendString:string];
NSLog(#"\n\nsoapResults: %#", soapResults);
}
}
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
if ([elementName isEqualToString:matchingElement]) {
returnedString = soapResults; // Save the element we found
elementFound = NO;
}
}
#end
I manage to send and get back the correct xml but it's actually doesn't start the parsing.
Any idea how can I solve it?

Answer 1

You are initiating an asynchronous NSURLConnection and then immediately starting the parsing process. You need to defer the initiation of the parsing until connectionDidFinishLoading, or you should do a synchronous NSURLConnection (but obviously, not from the main queue). Thus, while you're eventually getting a response, the parsing is undoubtedly initiated before the response has been received.