parse xml with namespaces with gdata xml

Question

i am developping an ios application and i am parsing my xml with gdataxml, but i am doing it wrong, my nslog is null

NSError *error = nil;
GDataXMLDocument *xmlResult = [[GDataXMLDocument alloc] initWithData:data options:0 error:&error];
if (error) {
    NSLog(@"%@",error);
}

NSLog(@"%@",xmlResult.rootElement); my root element is perfect, the error is with tempArray

NSArray *tempArray = [xmlResult nodesForXPath:@"//message/error/value" error:&error];

NSLog(@"mon array %@",tempArray);

my array is null,

my xml is like this :

<message xmlns="http://.....Api" xmlns:i="http://www.w3.org/....">
<error i:nil="true"/>
<value>

i am sur that my problème is with the namespace, but i don't how to do it ?

thanks for your answer

Answer 1

After some testing with GDataXMLNode, here is my answer:

NSArray *tempArray = [xmlResult nodesForXPath:@"//_def_ns:message/_def_ns:error/_def_ns:value" error:&error];

You can see this comment in GDataXMLNode.h:

// This implementation of nodesForXPath registers namespaces only from the
// document's root node.  _def_ns may be used as a prefix for the default
// namespace, though there's no guarantee that the default namespace will
// be consistenly the same namespace in server responses.

It states that you can actually use _def_ns as your namespace. However, you can also set your own namespace in case there are other namespaces in your document.

NSDictionary *myNS = [NSDictionary dictionaryWithObjectsAndKeys:
                      @"http://.....Api", @"ns1",
                      @"http://.....Other_Api", @"ns2", nil];
NSArray *tempArray = [xmlResult nodesForXPath:@"//ns1:message/ns1:error/ns1:value" namespaces:myNS error:&error];