ABRequestManager

About

ABRequestManager is a lightweight and extensible request manager for iOS/OS X. It requires only instance of NSURLRequest (or NSMutableURLRequest). All requests are stored in the queue. Request manager pulls the head request from queue and run it. And so on until queue is empty.

---

Installation

The recommended way to install Request Manager in your project is via CocoaPods. It's very easy. Just add ABRequestManager pod to your Podfile

---

Using

Send request with blocks

#import "NSURLRequest+RequestManager.h"
...
- ...
{
    ...
    NSURLRequest *request = [NSURLRequest requestWithURL:someURL];
    [request startWithCompleteBlock:^(NSHTTPURLResponse *response, id data)
    {
        // do some response routine
        ...
    }                     failBlock:^(NSError *error)
    {
        // handle error
        ...         
    }];
    ...
}

Note

Beware of retain cycles when using self

---

Send request with delegate

#import "NSURLRequest+RequestManager.h"
...
- (...
{
    ...
    NSURLRequest *request = [NSURLRequest requestWithURL:someURL];
    [request startWithDelegate:self];
    ...
}
...
- (void)request:(NSURLRequest *)request didReceiveResponse:(id)response
{
    // do some response routine
    ...
}
...
- (void)request:(NSURLRequest *)request didReceiveError:(NSError *)error
{
    // handle error
    ... 
}
...

Note for manual memory of management

Request delegate isn't retained by request manager. It means that if you don't sure that request completes before delegate deallocated you must cancel request

---

Parse received data

If received data needs to be parsed asynchronously, use start with parsing block Here is example of JSON-response parsing

...
NSURLRequest *request = [NSURLRequest requestWithURL:someURL];
[request startWithCompletedBlock:^(NSHTTPURLResponse *response, id result)
{
    // do something with parse JSON-object
    ...
}                    failedBlock:^(NSError *error)
{
    // handle error
    ...
}                   parsingBlock:^id(NSData *data)
{
    // parse data to JSON object
    id response = [NSJSONSerialization JSONObjectWithData:data
                                                  options:NSJSONReadingMutableContainers
                                                    error:nil];
    return response;
}];

And the same with delegate

...
NSURLRequest *request = [NSURLRequest requestWithURL:someURL];
[request startWithDelegate:self
              parsingBlock:^id(NSData *data)
{
    // parse data to JSON object
    id response = [NSJSONSerialization JSONObjectWithData:data
                                                  options:NSJSONReadingMutableContainers
                                                    error:nil];
    return response;
}];

Warning

All actions in block will run in background thread! Try to avoid calling objects of main thread. Otherwise you should synchronize calls

---

Cancel request

Request will be removed from requests queue. Connection will be dropped if it runs

[request cancelRequest];

---

Create request

It's easy to create request with ABRequestFactory

ABRequestFactory *factory = [ABRequestFactory requestFactory];
NSMutableURLRequest *requestGET = [factory createGETRequest:path];
NSMutableURLRequest *requestPOST = [factory createPOSTRequest:path data:data];
NSMutableURLRequest *requestPUT = [factory createPUTRequest:path data:data];
NSMutableURLRequest *requestDELETE = [factory createDELETERequest:path];
NSMutableURLRequest *requestCustom = [factory createRequest:path method:@"custom_method" data:data];

Note

Use [ABRequestFactory sharedInstance] if you don't want instantiate it every time

---

Request options

Create requests with custom options: base host path, request timeout interval, should handle cookies, cache policy, HTTP headers

ABRequestFactory *factory = [ABRequestFactory requestFactory];
factory.options.basePath = @"https://api.my-service.com/";
factory.options.timeout = 30.f;
factory.cookies = NO;
factory.cache = NSURLRequestReturnCacheDataDontLoad;
factory.headers = @{@"Content-Type", @"application/json"};
NSMutableURLRequest *request = [factory createGETRequest:@"news"]

Note

Default ABRequestFactory options are same as default NSURLRequest options

---

Advanced using

Here are some advanced features of ABRequestManager

Request wrapper

Every request in Request Manager wrapped into ABRequestWrapper. Sometimes it's better to use wrapper instead of raw request.

ABRequestWrapper *wrapper = [[ABRequestWrapper alloc] initWithURLRequest:request];
// set completed and failed blocks
[wrapper setCompletedBlock:^(ABRequestWrapper *wrapper, id result)
{
    // do some completion actions
    ...
}              failedBlock:^(ABRequestWrapper *wrapper)
{
    // show error
    ...
}];
// set parsing block
[wrapper setParsingBlock:^id(ABRequestWrapper *wrapper)
{
    id result = nil;
    // do parsing
    ...
    return result;
}];

---

Request manager instance

You aren't limited to only one sharedInstance. You can use custom instance of ABRequestManager. But in that case, you should use ABRequestWrapper instead of NSMutableURLRequest

ABRequestManager *manager = [[ABRequestManager alloc] init];
ABRequestWrapper *wrapper = [[ABRequestWrapper alloc] initWithURLRequest:request];
[wrapper setCompletedBlock:^(ABRequestWrapper *wrapper, id result)
{
    MyModel *model = [[MyModel alloc] initWithData:wrapper.data];
    [self updateViewWithModel:model];
}              failedBlock:^(ABRequestWrapper *wrapper)
{
    [UIAlertView showError:wrapper.error.localizedDescription];
}];
[manager addRequestWrapper:wrapper];

---

Request manager queue

Here is good example of complex task with easy solution. Imagine. Application deal with API that requires access via token. When token is expired it returns HTTP-code 401. And if application received this code, it should send 'get access token' request. And then retry last request.

ABRequestWrapper *wrapper = [[ABRequestWrapper alloc] initWithURLRequest:request];
[wrapper setCompletedBlock:^(ABRequestWrapper *wrapper, id result)
{
    if (wrapper.response.statusCode == 200)
    {
        // everything is OK, do something with result 
        ...
    }
    else if (wrapper.response.statusCode == 401)
    {
        // send 'get access token'
        ABRequestWrapper *getTokenWrapper= [self getAccessTokenRequestWrapper];
        [[ABRequestManager sharedInstance] addRequestWrapperFirst:getTokenWrapper];
        // retry current requeset
        [[ABRequestManager sharedInstance] addRequestWrapper:wrapper];
    }
    else
    {
        // handle other status codes
        ...
    }
}              failedBlock:^(ABRequestWrapper *wrapper)
{
    [UIAlertView showError:wrapper.error.localizedDescription];
}];

---

Request reachability

First of all you can set host which reachability should be checked.

...
{
    ...
    [[ABRequestManager sharedInstance] setReachabilityCheckHost:@"https://api.myhost.com"];
    ...
}
...

Note

Default reachability check host is "www.google.com"

---

Sometimes it can be useful to restart unfinished request when internet connection become available. But when host unreachable, request will be removed from queue. To avoid this you can restart request by implementing optional method of ABRequestDelegate

- (void)requestWrapperDidBecomeUnreachable:(ABRequestWrapper *)wrapper
{    
    // restarting request
    [[ABRequestManager sharedInstance] addRequestWrapperFirst:wrapper];
}

Note

If you don't implement this method delegate will receive requestWrapper:didFail: on internet connection lost

---

Specs

---

Updates

Stay tuned with Request Manager updates on @okolodev