i have been trying to implement the follow code , but I am having a hard time understanding the following code:
- (void)getRoutesWithStopName:(NSString *) stopName
success:(void (^)(NSArray *routes))success
error:(void (^)(NSString *errorMsg)) error
{
[[self AFManagerObject] POST:GET_ROUTES
parameters:#{#"params" : #{ #"stopName": [NSString stringWithFormat:#"%%%#%%",[stopName lowercaseString]]} }
success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSArray *routesRows = responseObject[#"rows"];
NSMutableArray *routes = [[NSMutableArray alloc] initWithCapacity:routesRows.count];
for(NSDictionary *dicRoute in routesRows)
{
FLBRoute *route = [[FLBRoute alloc] initWithAttrs:dicRoute];
[routes addObject:route];
}
success(routes);
}
failure:^(AFHTTPRequestOperation *operation, NSError *err) {
error(err.description);
}
];
}
I tried learning about blocks but I still can not understand what is going on here. Can you provide me a step by step explanation of the code ?
actually here used for webserviceCall
step-1
- (void)getRoutesWithStopName:(NSString *) stopName
success:(void (^)(NSArray *routes))success
error:(void (^)(NSString *errorMsg)) error
// here pass the one NSString and get the response using NSArray and failure using NSString
step-2
// here used AFNEtworking for call web service
//request block
[self AFManagerObject] -- NSObject class for AFNetworking method place.
POST:GET_ROUTES --> post is default function of request Type, GET_ROUTES --> your Macro class for Request URL
parameters --> send the parameter to server
[[self AFManagerObject] POST:GET_ROUTES
parameters:#{#"params" : #{ #"stopName": [NSString stringWithFormat:#"%%%#%%",[stopName lowercaseString]]} }
success:^(AFHTTPRequestOperation *operation, id responseObject)
{
/*********** success response serlize and store into Array**********/
NSArray *routesRows = responseObject[#"rows"];
NSMutableArray *routes = [[NSMutableArray alloc] initWithCapacity:routesRows.count];
for(NSDictionary *dicRoute in routesRows)
{
FLBRoute *route = [[FLBRoute alloc] initWithAttrs:dicRoute];
[routes addObject:route];
// this is your NSObject class for save the details ,
}
success(routes);
/************** success stop **********/
}
/*********** error if request is fail ************/
failure:^(AFHTTPRequestOperation *operation, NSError *err) {
error(err.description);
}
];
/*********** error if request is stop ************/
I think you need to read a little more about callbacks https://en.m.wikipedia.org/wiki/Callback_(computer_programming) and blocks https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/WorkingwithBlocks/WorkingwithBlocks.html and https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/Blocks/Articles/00_Introduction.html
Basically the method send a POST request and as you know it needs some time for the request to be sent to the server and for the server to respond. You don't want in this time your application to be freezed, so 2 callbacks are used, 1 for success case and 1 for failure case. A block callback is just a block of code that you want to be executed later, when the server will respond back, being a success or failure.
Related
Trying to improve my coding style and was wondering what the proper way of going about things is. Should they be placed in a NSObjects separate from the view controller and are there any open source clean code examples for me to reference online available?
As a general rule, it's always a good idea to separate code that accesses a back end server from your UI components. The one best reason being that it's often a requirement for several UI components to access the same server calls.
As far as examples, there are probably thousands. But perhaps a better idea might be to read up on things such as design patterns and app architectural patterns.
objc.io has some good articles on these subjects. Here's another on Medium. There are lots of other, just google search.
It's always a good idea to create a model if your app is going to be relying on an construct. I.e if you're building an app which contains a tableview full or photos, it's a good idea to create a model for photos.
Here are a few examples:
Clean Table View Code - Objc.io
In this tutorial, get an understanding of the best way to populate a tableview, and how the relationship works between a model, a cell, and a tableview.
A Weather App Case Study
This is an end-to-end walk through of building a model for your tableview, then populating the tableview.
MVC in Objective-C (II): Model
An overall understanding of how models fit into the MVC pattern.
If you want to construct an object form the JSON response you want to something like this:
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:responseObject options:0 error:&error];
// Sanity check
if ([json isKindOfClass:[NSDictionary class]]){
NSArray *jsonArray = json[#"items"];
// Sanity check
if ([jsonArray isKindOfClass:[NSArray class]]){
// Here you go through all your items one by one
for (NSDictionary *dictionary in jsonArray) {
Model *staff = [[Staff alloc] init];
model.id = [dictionary objectForKey:#"id"];
model.name = [dictionary objectForKey:#"name"];
model.attribute = [dictionary objectForKey:#"attribute"];
// Do this for all your attributes
[arrayContainingObjects addObject:model];
}
}
}
Use common NSObject Class for Calling WS with AFNetworking 2.0
First make NSObject Class with any name here i am creating NSObject Class With name Webservice.h and Webservice.m
Webservice.h
#interface Webservice : NSObject
+ (void)callWSWithUrl:(NSString *)stUrl parmeters:(NSDictionary *)parameters success:(void (^)(NSDictionary *response))success failure:(void (^)(NSError *error))failure;
#end
Webservice.m your nsobject.m file is look like this.(add two functions in .m file)
#import "Webservice.h"
#define kDefaultErrorCode 12345
#implementation Webservice
+ (void)callWSWithUrl:(NSString *)stUrl parmeters:(NSDictionary *)parameters success:(void (^)(NSDictionary *response))success failure:(void (^)(NSError *error))failure {
[self requestWithUrl:stUrl parmeters:parameters success:^(NSDictionary *response) {
//replace your key according your responce with "success"
if([[response objectForKey:#"success"] boolValue]) {
if(success) {
success(response);
}
}
else {
//replace your key according your responce with "message"
NSError *error = [NSError errorWithDomain:#"Error" code:kDefaultErrorCode userInfo:#{NSLocalizedDescriptionKey:[response objectForKey:#"message"]}];
if(failure) {
failure(error);
}
}
} failure:^(NSError *error) {
if(failure) {
failure(error);
}
}];
}
- (void)requestWithUrl:(NSString *)stUrl parmeters:(NSDictionary *)parameters success:(void (^)(NSDictionary *response))success failure:(void (^)(NSError *))failure {
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager setResponseSerializer:[AFHTTPResponseSerializer serializer]];
//remove comment if you want to use header
//[manager.requestSerializer setValue:#"" forHTTPHeaderField:#"Authorization"];
[manager GET:stUrl parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
if([responseObject isKindOfClass:[NSDictionary class]]) {
if(success) {
success(responseObject);
}
}
else {
NSDictionary *response = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingAllowFragments error:nil];
if(success) {
success(response);
}
}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
if(failure) {
failure(error);
}
}];}
#end
make sure you have to replace your dictionary key with success and
message for handling of responce callback function
Use like this call this common method from any viewcontroller.m and any methods from any viewControllers. for temporary i am using viewDidLoad for calling This WS.
- (void)viewDidLoad {
[super viewDidLoad];
NSDictionary *dictParam = #{#"parameter1":#"value1",#"parameter1":#"value2"};
[WebClient requestWithUrlWithResultVerificationWithLoder:#"add your webservice URL here" parmeters:dictParam success:^(NSDictionary *response) {
//Success
NSLog(#"responce:%#",response);
//code here...
} failure:^(NSError *error) {
//Error
NSLog(#"error:%#",error.localizedDescription);
}];
}
add your Parameter, values and webservice URL in upper method. you can easyly use this NSObjcet Class. for more details please visit AFNetworking or here.
I've been using AFNetworking 2.0 in my app.
I've noticed that if my web-service returns a 500 status code I do not get the body of the response.
Here is an example of my php code
try
{
$conn = new PDO( "sqlsrv:server=$serverName;Database = $database", $uid, $pwd);
$conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
return $conn;
}
catch( PDOException $e )
{
$response->status(500);
echo( "Connection Error: " . $e->getMessage() );
}
If I use a simple rest client this is an example of a response body.
Connection Error: SQLSTATE[08001]: [Microsoft][SQL Server Native Client 11.0]SQL Server Network Interfaces: Error Locating Server/Instance Specified [xFFFFFFFF].
However this seems to be the only response I can get from AFNetworking
Error Domain=NSCocoaErrorDomain Code=3840 "The operation couldn’t be completed. (Cocoa error 3840.)" (JSON text did not start with array or object and option to allow fragments not set.) UserInfo=0x15e58fa0 {NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}
This is the part of my objective-c code that does this.
...} failure:^(NSURLSessionDataTask *task, NSError *error) {
NSLog(#"%#",error.description);
}];
Is there a way I can get the response body?
Edit: More code for clarification
Below is part of my subclass of AFHTTPSessionManager
#implementation MSMAMobileAPIClient
+ (MSMAMobileAPIClient *)sharedClient {
static MSMAMobileAPIClient *_sharedClient = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
_sharedClient = [[MSMAMobileAPIClient alloc] initWithDefaultURL];
});
return _sharedClient;
}
- (id)initWithDefaultURL {
return [self initWithBaseURL:[NSURL URLWithString:[NSString stringWithFormat:#"https://%#/mamobile/index.php/" ,[[NSUserDefaults standardUserDefaults] stringForKey:#"serviceIPAddress"]]]];
}
- (id)initWithBaseURL:(NSURL *)url {
self = [super initWithBaseURL:url];
if (!self) {
return nil;
}
self.responseSerializer = [AFCompoundResponseSerializer compoundSerializerWithResponseSerializers:#[[AFJSONResponseSerializer serializer], [AFHTTPResponseSerializer serializer]]];
return self;
}
I tried setting the response serializer to a AFCompoundResponseSerializer but it didn't seem to make a difference
Below is an example of a subclass that I call the Librarian.
-(void)searchForItemWithString:(NSString *)searchString withCompletionBlock:(arrayBlock)block {
self.inventorySearchBlock = block;
NSDictionary *parameters = #{#"query": searchString};
[[MSMAMobileAPIClient sharedClient] GET:#"inventory/search" parameters:parameters success:^(NSURLSessionDataTask *task, id responseObject) {
if (!responseObject) {
NSLog(#"Error parsing JSON");
} else {
//do stuff with the json dictionary that's returned..
}
} failure:^(NSURLSessionDataTask *task, NSError *error) {
NSLog(#"Error: %#",error.description);
}];
}
UPDATE: I have created a github repository to contain the latest code I am using. All changes will be posted there. https://github.com/Hackmodford/HMFJSONResponseSerializerWithData
The answer comes from this issue on github.
https://github.com/AFNetworking/AFNetworking/issues/1397
gfiumara is the dev who came up with this. I have only slightly modified his subclass of AFJSONResponseSerializer to include an actual string instead of the NSData
//MSJSONResponseSerializerWithData.h
#import "AFURLResponseSerialization.h"
/// NSError userInfo key that will contain response data
static NSString * const JSONResponseSerializerWithDataKey = #"JSONResponseSerializerWithDataKey";
#interface MSJSONResponseSerializerWithData : AFJSONResponseSerializer
#end
// MSJSONResponseSerializerWithData.m
#import "MSJSONResponseSerializerWithData.h"
#implementation MSJSONResponseSerializerWithData
- (id)responseObjectForResponse:(NSURLResponse *)response
data:(NSData *)data
error:(NSError *__autoreleasing *)error
{
if (![self validateResponse:(NSHTTPURLResponse *)response data:data error:error]) {
if (*error != nil) {
NSMutableDictionary *userInfo = [(*error).userInfo mutableCopy];
userInfo[JSONResponseSerializerWithDataKey] = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSError *newError = [NSError errorWithDomain:(*error).domain code:(*error).code userInfo:userInfo];
(*error) = newError;
}
return (nil);
}
return ([super responseObjectForResponse:response data:data error:error]);
}
#end
Here is an example of how I use it in the failure block.
} failure:^(NSURLSessionDataTask *task, NSError *error) {
NSLog(#"%#",[error.userInfo objectForKey:#"JSONResponseSerializerWithDataKey"]);
}];
You need to use AFCompoundSerializer to tell the AFNetworking framework how to process all of the possible responses it could receive. By default it will only try to map JSON. A compound serializer will work through the serializers until it finds one that doesn't raise an error.
You want to use:
+ (instancetype)compoundSerializerWithResponseSerializers:(NSArray *)responseSerializers
on AFCompoundResponseSerializer (in AFURLResponseSerialization.h).
You need to pass an array of serializers that can handle the response. One of the serializers in the array should be an instance of AFHTTPResponseSerializer to handle your error responses.
If you include my category in your project, it's as simple as the following:
[mySessionManager POST:#"some-api" parameters:params success:^(NSURLSessionDataTask *task, NSDictionary *responseObject) {
...
} failure:^(NSURLSessionDataTask *task, NSError *error) {
id responseObject = error.userInfo[kErrorResponseObjectKey];
... do something with the response ...
}];
Here's the code for my category. It swizzles AFURLSessionManager to inject a shim into the completion handler. The shim puts the response into the NSError's userInfo.
https://gist.github.com/chrishulbert/35ecbec4b37d36b0d608
I am doing a simple GET request with AFNetworking
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager GET:#"http://someapi.com/hello.json" parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"JSON: %#", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Error: %#", error);
}];
Once I have made the request I want to be able to access the responseObject from any other method in the class.
I want to be able to save the responseObject so I can do something like display the output in a tableview.
It's common to creat object models that will be represented by JSON. When you get the response you would then parse the data into the models. The approach we use is to return the response to the requester through a completion block. You don't have to parse the JSON into strongly typed objects, but it really is helpful long term. It's probably a good idea to farm out the network request operations into a separate class (called a service) as well. This way you can instantiate a new service and get notified through a completion block that it is finished. For example your service's request signature could look like this:
typedef void(^HelloWorldCompletionHandler)(NSString *helloWorld, NSError *error);
- (void)requestHelloWorldData:(HelloWorldCompletionHandler)completionHandler;
// implementation
- (void)requestHelloWorldData:(HelloWorldCompletionHandler)completionHandler {
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager GET:#"http://someapi.com/hello.json" parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
id JSONResponse = [operation responseObject];
if (operation.error) {
completionHandler(nil, error);
} else {
// parse the response to something
id parserResult = [self parseJSONResponse:JSONResponse];
completionHandler(parserResult, nil);
}
}];
This way you'll know when the network request is complete, and you can set the data you want on a property within your class. Then you could call tableView.reloadData in order to use the data in your table.
All that code would go into a service type class. I like to organize my services by responsibility. I don't know how many different data calls you make, but we have several for our project. If for instance you were making a weather app you could potentially organize by Current Conditions, Daily Forecasts, and Hourly Forecasts. I would make a service for each one of these requests. Say I created a CurrentConditionsService. The header would look something like this:
typedef void(^CurrentConditionsCompletionHandler)(CurrentConditions *currentConditions, NSError *error);
#interface CurrentConditionsService : NSObject
// locationKey is some unique identifier for a city
+ (instancetype)serviceWithLocationKey:(NSString *)locationKey;
- (void)retrieveCurrentConditionsWithCompletionHandler:(CurrentConditionsCompletionHandler)completionHandler;
#end
Then in my implementation file I would make the request and invoke the given completion handler like I demonstrated above. This pattern can be followed by many different services to the point where all your services could inherit from a base class that handles the request/response portions. Then your subclasses could override specific methods and handle/parse the data appropriately based on type.
If you go the route of parsing the JSON responses into model objects, all your parsers will need to conform to a protocol. This way in your super class it doesn't matter what the concrete implementation of your parser is. You supply the super class with a concrete implementation and all it knows how to do is invoke the parser and return the response.
An example JSON parser protocol would look like this:
#protocol AWDataParser <NSObject>
#required
- (id)parseFromDictionary:(NSDictionary *)dictionary;
- (NSArray *)parseFromArray:(NSArray *)array;
#end
And invoking it in your services super class:
- (id)parseJSONResponse:(id)JSONResponse error:(NSError **)error {
NSAssert(self.expectedJSONResponseClass != nil, #"parseResponse: expectedJSONResponseClass cannot be nil");
NSAssert(self.parser != nil, #"parseResponse: parser cannot be nil");
id parserResult = nil;
if (![JSONResponse isKindOfClass:self.expectedJSONResponseClass]) {
//handle invalid JSON reponse object
if (error) {
*error = [NSError errorWithDomain:NetworkServiceErrorDomain code:kNetworkServiceErrorParsingFailure userInfo:#{#"Invalid JSON type": [NSString stringWithFormat:#"expected: %#, is: %#",self.expectedJSONResponseClass, [JSONResponse class]]}];
}
} else {
if (self.expectedJSONResponseClass == [NSArray class]) {
parserResult = [self.parser parseFromArray:JSONResponse];
}else {
parserResult = [self.parser parseFromDictionary:JSONResponse];
}
if (!parserResult) {
if (error) {
*error = [NSError errorWithDomain:NetworkServiceErrorDomain code:kNetworkServiceErrorParsingFailure userInfo:nil];
}
}
}
return parserResult;
}
Use this approach:
NSURL *COMBINAT = [[NSURL alloc] initWithString:#"http://someapi.com/hello.json"];
dispatch_async(kBgQueue, ^{
NSData* data = [NSData dataWithContentsOfURL:
COMBINAT];
[self performSelectorOnMainThread:#selector(savedata:) withObject:data waitUntilDone:YES];
});
then simply call:
- (void)savedata:(NSData *)responseData {
NSError* error;
NSLog(#"Answer from server %#", responseData);
// ... your code to use responseData
}
Just create a property:
#property(nonatomic, strong) id savedResponseObject;
and set it in the success handler of the request:
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager GET:#"http://someapi.com/hello.json"
parameters:nil
success:^(AFHTTPRequestOperation *operation, id responseObject)
{
self.savedResponseObject = responseObject;
}
failure:^(AFHTTPRequestOperation *operation, NSError *error)
{
NSLog(#"Error: %#", error);
}];
Then you will be able to access it from other places in your class by referencing:
self.savedResponseObject
i am new to iOS programming, still learning.
EDIT: !!!!!! Everything in my code works. My question is about the delegation pattern i use,
if i am generating problems in the background that i have no idea of, or if there is a better way to handle my situation in AFNetworking...
I have created an API for my app by subclassing AFHTTPSessionManager.
My API creates a singleton and returns it and supplies public functions for various requests. And those functions create parameter lists, and make GET requests on the server like this:
- (void)getCharacterListForKeyID:(NSString *)keyID vCode:(NSString *)vCode sender:(id)delegate
{
NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
parameters[#"keyID"] = keyID;
parameters[#"vCode"] = vCode;
[self GET:#"account/Characters.xml.aspx" parameters:parameters success:^(NSURLSessionDataTask *task, id responseObject) {
self.xmlWholeData = [NSMutableDictionary dictionary];
self.errorDictionary = [NSMutableDictionary dictionary];
NSXMLParser *XMLParser = (NSXMLParser *)responseObject;
[XMLParser setShouldProcessNamespaces:YES];
XMLParser.delegate = self;
[XMLParser parse];
if ([delegate respondsToSelector:#selector(EVEAPIHTTPClient:didHTTPRequestWithResult:)]) {
[delegate EVEAPIHTTPClient:self didHTTPRequestWithResult:self.xmlWholeData];
}
} failure:^(NSURLSessionDataTask *task, NSError *error) {
if ([delegate respondsToSelector:#selector(EVEAPIHTTPClient:didFailWithError:)]) {
[delegate EVEAPIHTTPClient:self didFailWithError:error];
}
}];
}
I was using a normal protocol/delegate method earlier. But once i make calls this API more than once like this: (IT WAS LIKE THIS:)
EVEAPIHTTPClient *client = [EVEAPIHTTPClient sharedEVEAPIHTTPClient];
client.delegate = self;
[client getCharacterListForKeyID:self.keyID vCode:self.vCode];
Previous call's delegate was being overwritten by next. So i changed to above style. Passing sender as an argument in the function:
EVEAPIHTTPClient *client = [EVEAPIHTTPClient sharedEVEAPIHTTPClient];
[client getCharacterListForKeyID:self.keyID vCode:self.vCode sender:self];
And i pass this sender to GET request's success and failure blocks.
What i wonder is : "Is this a good programming practice ?". Passing objects to blocks like this should be avoided if possible ? Is there any other more elegant way in AFHTTPSessionManager to handle this type of work (making same GET request over and over with different parameters and returning results to the respective request owners) more elegantly ?
Delegation pattern falters when it comes to simplicity and asynchronous request processing. You should be using blocks, here's an example
Your server class:
static NSString *const kNews = #"user_news/"; // somewhere above the #implementation
- (NSURLSessionDataTask *)newsWithPage:(NSNumber *)page
lastNewsID:(NSNumber *)lastNewsID
completion:(void (^)(NSString *errMsg, NSArray *news, NSNumber *nextPage))completionBlock {
return [self GET:kNews
parameters:#{#"page" : page,
#"news_id" : lastNewsID
}
success:^(NSURLSessionDataTask *task, id responseObject) {
NSArray *news = nil;
NSNumber *nextPage = nil;
NSString *errors = [self errors:responseObject[#"errors"]]; // process errors
if ([responseObject[#"status"] boolValue]) {
news = responseObject[#"news"];
nextPage = responseObject[#"next_page"];
[self assignToken];
}
completionBlock(errors, news, nextPage);
}
failure:^(NSURLSessionDataTask *task, NSError *error) {
NSString *errors = [self errors:error];
completionBlock(errors, nil, nil);
}];
}
The caller
- (void)dealloc {
[_task cancel]; // you don't want this task to execute if user suddenly removes your controller from the navigation controller's stack
}
- (void)requestNews {
typeof(self) __weak wself = self; // to avoid the retain cycle
self.task = [[GSGServer sharedInstance] newsWithPage:self.page
lastNewsID:self.lastNewsID
completion:^(NSString *errMsg, NSArray *news, NSNumber *nextPage) {
if (errMsg) {
[GSGAppDelegate alertQuick:errMsg]; // shortcut for posting UIAlertView, uses errMsg for message and "Error" as a title
return;
}
[wself.news addObjectsFromArray:news];
wself.lastNewsID = [wself.news firstObject][#"id"];
wself.page = nextPage;
[wself.tableView reloadData];
}];
}
I've been using AFNetworking 2.0 in my app.
I've noticed that if my web-service returns a 500 status code I do not get the body of the response.
Here is an example of my php code
try
{
$conn = new PDO( "sqlsrv:server=$serverName;Database = $database", $uid, $pwd);
$conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
return $conn;
}
catch( PDOException $e )
{
$response->status(500);
echo( "Connection Error: " . $e->getMessage() );
}
If I use a simple rest client this is an example of a response body.
Connection Error: SQLSTATE[08001]: [Microsoft][SQL Server Native Client 11.0]SQL Server Network Interfaces: Error Locating Server/Instance Specified [xFFFFFFFF].
However this seems to be the only response I can get from AFNetworking
Error Domain=NSCocoaErrorDomain Code=3840 "The operation couldn’t be completed. (Cocoa error 3840.)" (JSON text did not start with array or object and option to allow fragments not set.) UserInfo=0x15e58fa0 {NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}
This is the part of my objective-c code that does this.
...} failure:^(NSURLSessionDataTask *task, NSError *error) {
NSLog(#"%#",error.description);
}];
Is there a way I can get the response body?
Edit: More code for clarification
Below is part of my subclass of AFHTTPSessionManager
#implementation MSMAMobileAPIClient
+ (MSMAMobileAPIClient *)sharedClient {
static MSMAMobileAPIClient *_sharedClient = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
_sharedClient = [[MSMAMobileAPIClient alloc] initWithDefaultURL];
});
return _sharedClient;
}
- (id)initWithDefaultURL {
return [self initWithBaseURL:[NSURL URLWithString:[NSString stringWithFormat:#"https://%#/mamobile/index.php/" ,[[NSUserDefaults standardUserDefaults] stringForKey:#"serviceIPAddress"]]]];
}
- (id)initWithBaseURL:(NSURL *)url {
self = [super initWithBaseURL:url];
if (!self) {
return nil;
}
self.responseSerializer = [AFCompoundResponseSerializer compoundSerializerWithResponseSerializers:#[[AFJSONResponseSerializer serializer], [AFHTTPResponseSerializer serializer]]];
return self;
}
I tried setting the response serializer to a AFCompoundResponseSerializer but it didn't seem to make a difference
Below is an example of a subclass that I call the Librarian.
-(void)searchForItemWithString:(NSString *)searchString withCompletionBlock:(arrayBlock)block {
self.inventorySearchBlock = block;
NSDictionary *parameters = #{#"query": searchString};
[[MSMAMobileAPIClient sharedClient] GET:#"inventory/search" parameters:parameters success:^(NSURLSessionDataTask *task, id responseObject) {
if (!responseObject) {
NSLog(#"Error parsing JSON");
} else {
//do stuff with the json dictionary that's returned..
}
} failure:^(NSURLSessionDataTask *task, NSError *error) {
NSLog(#"Error: %#",error.description);
}];
}
UPDATE: I have created a github repository to contain the latest code I am using. All changes will be posted there. https://github.com/Hackmodford/HMFJSONResponseSerializerWithData
The answer comes from this issue on github.
https://github.com/AFNetworking/AFNetworking/issues/1397
gfiumara is the dev who came up with this. I have only slightly modified his subclass of AFJSONResponseSerializer to include an actual string instead of the NSData
//MSJSONResponseSerializerWithData.h
#import "AFURLResponseSerialization.h"
/// NSError userInfo key that will contain response data
static NSString * const JSONResponseSerializerWithDataKey = #"JSONResponseSerializerWithDataKey";
#interface MSJSONResponseSerializerWithData : AFJSONResponseSerializer
#end
// MSJSONResponseSerializerWithData.m
#import "MSJSONResponseSerializerWithData.h"
#implementation MSJSONResponseSerializerWithData
- (id)responseObjectForResponse:(NSURLResponse *)response
data:(NSData *)data
error:(NSError *__autoreleasing *)error
{
if (![self validateResponse:(NSHTTPURLResponse *)response data:data error:error]) {
if (*error != nil) {
NSMutableDictionary *userInfo = [(*error).userInfo mutableCopy];
userInfo[JSONResponseSerializerWithDataKey] = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSError *newError = [NSError errorWithDomain:(*error).domain code:(*error).code userInfo:userInfo];
(*error) = newError;
}
return (nil);
}
return ([super responseObjectForResponse:response data:data error:error]);
}
#end
Here is an example of how I use it in the failure block.
} failure:^(NSURLSessionDataTask *task, NSError *error) {
NSLog(#"%#",[error.userInfo objectForKey:#"JSONResponseSerializerWithDataKey"]);
}];
You need to use AFCompoundSerializer to tell the AFNetworking framework how to process all of the possible responses it could receive. By default it will only try to map JSON. A compound serializer will work through the serializers until it finds one that doesn't raise an error.
You want to use:
+ (instancetype)compoundSerializerWithResponseSerializers:(NSArray *)responseSerializers
on AFCompoundResponseSerializer (in AFURLResponseSerialization.h).
You need to pass an array of serializers that can handle the response. One of the serializers in the array should be an instance of AFHTTPResponseSerializer to handle your error responses.
If you include my category in your project, it's as simple as the following:
[mySessionManager POST:#"some-api" parameters:params success:^(NSURLSessionDataTask *task, NSDictionary *responseObject) {
...
} failure:^(NSURLSessionDataTask *task, NSError *error) {
id responseObject = error.userInfo[kErrorResponseObjectKey];
... do something with the response ...
}];
Here's the code for my category. It swizzles AFURLSessionManager to inject a shim into the completion handler. The shim puts the response into the NSError's userInfo.
https://gist.github.com/chrishulbert/35ecbec4b37d36b0d608