iPhone ASIHTTP - Distinguishing between API calls?

问题:

I currently have a view controller that implements ASIHTTP for handling API calls.

My view controller fires 2 separate calls. I need to be able to distinguish between the 2 calls in the -requestFinished(ASIHTTPRequest*)request method, so I can parse each one accordingly...

Is there any of doing this?

回答1:

Use the userInfo field! That's what it's for!

An ASIHTTPRequest (or an ASIFormDataRequest) object has a property called .userInfo that can take an NSDictionary with anything in it you want. So I pretty much always go:

- (void) viewDidLoad { // or wherever
    ASIHTTPRequest *req = [ASIHTTPRequest requestWithUrl:theUrl];
    req.delegate = self;
    req.userInfo = [NSDictionary dictionaryWithObject:@"initialRequest" forKey:@"type"];
    [req startAsynchronous];
}

- (void)requestFinished:(ASIHTTPRequest *)request
{
    if ([[request.userInfo valueForKey:@"type"] isEqualToString:@"initialRequest"]) {
        // I know it's my "initialRequest" .req and not some other one!
        // In here I might parse my JSON that the server replied with, 
        // assemble image URLs, and request them, with a userInfo
        // field containing a dictionary with @"image" for the @"type", for instance.
    }
}

Set a different value for the object at key @"type" in each different ASIHTTPRequest you do in this view controller, and you can now distinguish between them in -requestFinished: and handle each of them appropriately.

If you're really fancy, you can carry along any other data that would be useful when the request finishes. For instance, if you're lazy-loading images, you can pass yourself a handle to the UIImageView that you want to populate, and then do that in -requestFinished after you've loaded the image data!

回答2:

You can inspect the request parameter passed to your requestFinished:(ASIHTTPRequest *)request method to differentiate between the two calls.

For example, if the two calls have different URLs, you can inspect the request.url property to differentiate between the two requests.

回答3:

You can set the appropriate selectors which should be called at request creation:

[request setDelegate: self];
[request setDidFailSelector: @selector(apiCallDidFail:)];
[request setDidFinishSelector: @selector(apiCallDidFinish:)];

Just set different selectors for different calls

回答4:

You can check the url/originalUrl properties OR you can subclass it and add your own property to indicate the call how I do it because it is easier/faster to compare ints than strings.

i.e.

myRequest.callType = FACEBOOK_LOGIN;

I have all the calls in an enum like this:

enum calls {
FACEBOOK_LOGIN = 101,
FACEBOOK_GETWALL = 102,
...
}