Logic Issue - NSObject class - Beginner - iphone

Question

I have 2 questions.
1.) I am creating a NSObject class, and i am having the following code in it. (ASIHTTPRequest POST).
The name of the NSObject class is called, SendToServer. I call the class as follows;
SendToServer *sv = [[SendToServer alloc]];
sv.grabURLInTheBackground ;
NSLog(#"This line is executed ");
The following is the code that is in the SendToServer NSObject class.
- (void)grabURLInTheBackground
{
if (![self queue]) {
[self setQueue:[[[NSOperationQueue alloc] init] autorelease]];
}
NSURL *url = [NSURL URLWithString:#"http://allseeing-i.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request setDidFinishSelector:#selector(requestDone:)];
[request setDidFailSelector:#selector(requestWentWrong:)];
[[self queue] addOperation:request]; //queue is an NSOperationQueue
}
- (void)requestDone:(ASIHTTPRequest *)request
{
NSString *response = [request responseString];
}
- (void)requestWentWrong:(ASIHTTPRequest *)request
{
NSError *error = [request error];
}
The problem is that, the code executes the line sv.grabURLInTheBackground ; and before it executes the requestDone or requestWentWrong methods, it executes the NSLog (NSLog(#"This line is executed "); )
What i want my program to do is to complete all the operations in the SendToServer NSObject class and then Execute the NSLog (In a sequence).
First execute sv.grabURLInTheBackground ; once all the activities in that method/class is over, then return to the code and execute the other line which is NSLog(#"This line is executed "); .
2.) I need to return a String when the requestDone method is executed. How do i modify the code to do so;
- (NSString * )requestDone:(ASIHTTPRequest *)request {
}
but how do i edit [request setDidFinishSelector:#selector(requestDone:)];, for the above code ?
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EDIT
I am doing this for user login. Upon button click i will be calling the grabURLInTheBackground method from the NSObject class. And the viewcontroller needs to know if the user login was successful or failed.
SendToServer *sv = [[SendToServer alloc]];
[sv grabURLInTheBackground] ;
NSLog(#"User login SUcess or failed %#", [sv userloginSucessOrFail]);
For example say [sv userloginSucessOrFail] returns if the user login was success or failed.
What hapence here, is that after [sv grabURLInTheBackground] is called, it directly goes and executes the NSLog(#"User login SUcess or failed %#", [sv userloginSucessOrFail]); line of code.
What i want is, i need to find a way to let my ViewCOntroller know if the user login was a Success or failure.

Answer 1

First: call init on your object.
Second: grabURLInTheBackground is a method not a property. It should by called with square brackets
So you code becomes:
SendToServer *sv = [[SendToServer alloc] init];
[sv grabURLInTheBackground];
NSLog(#"This line is executed ");
To accomplish point 1) you need to make a synchronous request
NSURL *url = [NSURL URLWithString:#"http://allseeing-i.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request startSynchronous];
NSError *error = [request error];
if (!error) {
NSString *response = [request responseString];
}
The problem is that if this code is executed on the main thread is blocking (not good)...
For the second point. You can't.
EDIT:
What you have to do is something like the following steps:
Before calling grabURLInTheBackground you have to notify the user that a request is pending.. like putting an UIActivityIndicator, or disabling the UI,...
when you receive the callback then update the UI: hide the activity indicator, re-enable the UI... or if the request failed, notify the user.