Wednesday, May 23, 2012

Consume WCF Web Service using Objective-C on iPhone


I am having a hard time consuming a very simple (Hello World) WCF web service in my iPhone app. From what I have read, you must manually create the request message then send it to the web service URL.



I was able to accomplish this on a .asmx web service, but not with a WCF service.



How do I know the correct format of the request SOAP message?



The web service I am trying to hit has a format of: http://xxx.xxx.xxx.xxx:PORT/IService1/ (running locally in a VM)



I apologize for the lack of information, I am pretty lost.



Any and all help is much appreciated.


Source: Tips4all
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5 comments:

  1. UserMay 23, 2012 at 2:53 AM

    Thank to everyone that helped here. I ended up figuring it out and thought I would share my results. I know this is not a comprehensive solution, so shoot me a message or comment if you require more detail.

    //Variables used
    NSMutableData *webData;
    NSMutableString *soapResults;
    NSXMLParser *xmlParser;
    BOOL recordResults;

    //Web Service Call
    NSString *soapMessage = [NSString stringWithFormat:
    @"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
    "<SOAP-ENV:Envelope \n"
    "xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" \n"
    "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" \n"
    "xmlns:SOAP-ENC=\"http://schemas.xmlsoap.org/soap/encoding/\" \n"
    "SOAP-ENV:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\" \n"
    "xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope/\"> \n"
    "<SOAP-ENV:Body> \n"
    "<Login xmlns=\"http://tempuri.org/\"><username>JACKSON</username><password>PASSWORD</password>"
    "</Login> \n"
    "</SOAP-ENV:Body> \n"
    "</SOAP-ENV:Envelope>"];

    NSURL *url = [NSURL URLWithString:@"http://172.16.0.142:8731/Service1/"];
    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/IService1/Login" 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");
    }

    //Implement the NSURL and XMLParser protocols
    #pragma mark -
    #pragma mark NSURLConnection methods

    - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response

    - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data

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

    - (void)connectionDidFinishLoading:(NSURLConnection *)connection

    #pragma mark -
    #pragma mark XMLParser methods

    -(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName
    namespaceURI:(NSString *)namespaceURI
    qualifiedName:(NSString *)qName
    attributes:(NSDictionary *)attributeDict

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

    -(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName
    namespaceURI:(NSString *)namespaceURI
    qualifiedName:(NSString *)qName

    ReplyDelete
  2. UserMay 23, 2012 at 2:53 AM

    Have you tried to access the WCF service as a Web Service from a windows client? I haven't configured WCF to run as an asmx styled Web Service but I believe there are some specific settings that have to be tweaked to get WCF to act like in that manner. Working with a windows client would take out any iphone based issues out of the picture for testing purposes and would help you narrow your testing to the service itself.

    ReplyDelete
  3. UserMay 23, 2012 at 2:53 AM

    Caged / httpriot Simple HTTP Rest Library for iPhone and Cocoa projects.

    ReplyDelete
  4. UserMay 23, 2012 at 2:53 AM

    You need to make sure that you are using BasicHttpBinding (not WSHttpBinding) which is aimed more are clients that are not on the .NET 3.0 platform. This Binding does not support security, reliability or ordered delivery.

    ReplyDelete
  5. UserMay 23, 2012 at 2:53 AM

    What kind of error are you getting when you hit our WCF service? So asmx is working but not WCF? One thing you need to pay attention is that in .NET 2.0, the web services (asmx) supported both SOAP 1.1 and SOAP 1.2 messages. However, basicHttpBinding in WCF handles only SOAP 1.1. So if you're sending SOAP 1.2 messages from your iPhone client to the WCF service with basicHttpBinding, this could very well be the problem you're having. In order to support SOAP 1.2, you need to use wsHttpBinding or create a custom binding pretty much the same as basicHttpBinding but you specify the message version to be SOAP 1.2.

    <customBinding>
    <binding name="customHttpBindingWithSoap12">
    <textMessageEncoding messageVersion="Soap12"/>
    <httpTransport />
    </binding>
    </customBinding>

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