How to post and get asmx web serivce access using iPhone app? - iphone

Question

I am new to iPhone app development. How can I post data and get data by accessing the asmx web service using iPhone app?

Answer 1

I think asmx webservices are SOAP webservices you should read my blog entry here -
http://www.makebetterthings.com/iphone/call-soap-web-service-from-iphone/
To call a SOAP service first i create a string with the SOAP request as follows.
NSString *soapMessage = #"<?xml version="1.0" encoding="utf-8"?>n"
"<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">n"
"<soap:Body>n"
"<CelsiusToFahrenheit xmlns="http://tempuri.org/">n"
"<Celsius>50</Celsius>n"
"</CelsiusToFahrenheit>n"
"</soap:Body>n"
"</soap:Envelope>n";
After creating the SOAP request I create a NSMutableRequest to send this request to server.
NSURL *url = [NSURL URLWithString:#"http://w3schools.com/webservices/tempconvert.asmx"];
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url];
NSString *msgLength = [NSString stringWithFormat:#"%d", [soapMessage length]];
[theRequest addValue: #"text/xml; charset=utf-8" forHTTPHeaderField:#"Content-Type"];
[theRequest addValue: #"http://tempuri.org/CelsiusToFahrenheit" forHTTPHeaderField:#"SOAPAction"];
[theRequest addValue: msgLength forHTTPHeaderField:#"Content-Length"];
[theRequest setHTTPMethod:#"POST"];
[theRequest setHTTPBody: [soapMessage dataUsingEncoding:NSUTF8StringEncoding]];
NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if( theConnection )
{
webData = [[NSMutableData data] retain];
}
else
{
NSLog(#"theConnection is NULL");
}
After firing the request we can collect the XML response in the NSURLConnection’s delegate methods.
-(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
{
NSLog(#"ERROR with theConenction");
[connection release];
[webData release];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSLog(#"DONE. Received Bytes: %d", [webData length]);
NSString *theXML = [[NSString alloc] initWithBytes: [webData mutableBytes] length:[webData length] encoding:NSUTF8StringEncoding];
NSLog(#"%#",theXML);
[theXML release];
}
After collecting the XML response in theXML string in -(void)connectionDidFinishLoading:(NSURLConnection *)connection
we can parse this string using TBXML for any other XML parser you like.