AFURLSessionManager/AFHTTPSessionManager parsing

The AFN structure

  • AFNetworking
  • The core
    • AFURLSessionManager
    • AFHTTPSessionManager
  • serialization
    • AFURLRequestSerialization
    • AFHTTPSerializer
    • AFJSONRequestSerializer
    • AFPropertyRequestSerializer
    • AFURLResponseSerialization
    • AFHTTPResponseSerializer
    • AFJSONResponseSerializer
    • AFXMLParserResponseSerializer
    • AFXMLDocumentResponseSerializer(macOS)
    • AFPropertyListResponseSrializer
    • AFImageResponseSerializer
    • AFCompoundResponseSerializer
  • Auxiliary class
    • AFSecurityPolicy
    • AFNetworkReachabilityManager
    • The UI class
    • .

Initialization of AFHTTPSessionManager

AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];

AFHTTPSessionManager Initializes the internal process

  • 1.Layer by layer to the parent class(AFURLSessionManager)The initialization method of

- (instancetype)initWithSessionConfiguration:(NSURLSessionConfiguration *)configuration;

  • Gets or creates defaultsconfigurationAnd hold
if(! configuration) { configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
}
self.sessionConfiguration = configuration;
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  • Initialize the serial queue (serial queue, apple documentation requires, to make sure the callbacks are in the correct order), for generationsession
self.operationQueue = [[NSOperationQueue alloc] init];
self.operationQueue.maxConcurrentOperationCount = 1;
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  • Initialize thesessionAnd hold,sessionThere will be more than onetask
self.session = [NSURLSession sessionWithConfiguration:self.sessionConfiguration delegate:self delegateQueue:self.operationQueue];
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  • Setting resolution (defaultJSON), certificate (default unconditional trusthttps), network status monitoring
self.responseSerializer = [AFJSONResponseSerializer serializer];
self.securityPolicy = [AFSecurityPolicy defaultPolicy];
self.reachabilityManager = [AFNetworkReachabilityManager sharedManager];
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  • Initialize oneNSMutableDictionaryFor storing bindingstaskanddelegate(@{key:delegate]})
self.mutableTaskDelegatesKeyedByTaskIdentifier = [[NSMutableDictionary alloc] init];
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  • Initialize the thread lock
self.lock = [[NSLock alloc] init];
self.lock.name = AFURLSessionManagerLockName;
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  • Asynchronously get the currentsessionAll unfinishedtask(such as initialization after coming back from the backgroundsession, there may be previous missions)
[self.session getTasksWithCompletionHandler:^(NSArray *dataTasks, NSArray *uploadTasks, NSArray *downloadTasks) {
    for (NSURLSessionDataTask *task in dataTasks) {
        [self addDelegateForDataTask:task uploadProgress:nil downloadProgress:nil completionHandler:nil];
    }

    for (NSURLSessionUploadTask *uploadTask in uploadTasks) {
        [self addDelegateForUploadTask:uploadTask progress:nil completionHandler:nil];
    }
    
    for (NSURLSessionDownloadTask *downloadTask in downloadTasks) {
        [self addDelegateForDownloadTask:downloadTask progress:nil destination:nil completionHandler:nil]; }}];Copy the code
  • 2.To deal withurlTo giveurlJoining together"/"
if ([[url path] length] > 0 && ![[url absoluteString] hasSuffix:@ "/"]) {
    url = [url URLByAppendingPathComponent:@ ""];
}
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  • 3.holdbaseURL
self.baseURL = url;
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  • 4.Set serialization defaults
self.requestSerializer = [AFHTTPRequestSerializer serializer];
self.responseSerializer = [AFJSONResponseSerializer serializer];
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Initiate a request and generate NSURLSessionDataTask

  • generaterequest
NSMutableURLRequest *request = [self.requestSerializer requestWithMethod:method URLString:[[NSURL URLWithString:URLString relativeToURL:self.baseURL] absoluteString] parameters:parameters error:&serializationError];
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  • generateNSMutableURLRequestAnd set the request mode
NSMutableURLRequest *mutableRequest = [[NSMutableURLRequest alloc] initWithURL:url];
mutableRequest.HTTPMethod = method;
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  • traversemutableObservedChangedKeyPathsTo givemutableRequestforKVCThe assignment
    • inrequestSerializerWhen you initialize, it’s going to bemutableObservedChangedKeyPathsforKVOoperation
for (NSString *keyPath in AFHTTPRequestSerializerObservedKeyPaths()) {
    if ([self.mutableObservedChangedKeyPaths containsObject:keyPath]) {
        [mutableRequest setValue:[selfvalueForKeyPath:keyPath] forKey:keyPath]; }}Copy the code
  • Encode the parameters and pass them tomutableRequest
mutableRequest = [[self requestBySerializingRequest:mutableRequest withParameters:parameters error:error] mutableCopy];
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  • Execute copy
NSMutableURLRequest *mutableRequest = [request mutableCopy];
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  • Set the request header
[self.HTTPRequestHeaders enumerateKeysAndObjectsUsingBlock:^(id field, id value, BOOL * __unused stop) {
    if (![request valueForHTTPHeaderField:field]) {
        [mutableRequest setValue:value forHTTPHeaderField:field];
    }
}];
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  • Converts the parameter dictionary into a string to support custom parsing
1.Let's do the recursionNSArray * AFQueryStringPairsFromKeyAndValue(NSString *key, idValue) gets the AFQueryStringPair parameter array2.It then iterates through the parameter array to perform URLEncodedStringValue percent encoding on AFQueryStringPair3.The array parameters of AFQueryStringPair componentsJoinedByString:@ "&"Elements segmentation get AFQueryStringFromParameters string parametersCopy the code
NSString * AFQueryStringFromParameters(NSDictionary *parameters) {
    NSMutableArray *mutablePairs = [NSMutableArray array];
    for (AFQueryStringPair *pair in AFQueryStringPairsFromDictionary(parameters)) {
        [mutablePairs addObject:[pair URLEncodedStringValue]];
    }
    return [mutablePairs componentsJoinedByString:@ "&"];
}
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NSArray * AFQueryStringPairsFromDictionary(NSDictionary *dictionary) {
    return AFQueryStringPairsFromKeyAndValue(nil, dictionary);
}
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NSArray * AFQueryStringPairsFromKeyAndValue(NSString *key, id value) {
    NSMutableArray *mutableQueryStringComponents = [NSMutableArray array];
    NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"description" ascending:YES selector:@selector(compare:)];
    if ([value isKindOfClass:[NSDictionary class]]) {
        NSDictionary *dictionary = value;
        for (id nestedKey in [dictionary.allKeys sortedArrayUsingDescriptors:@[ sortDescriptor ]]) {
            id nestedValue = dictionary[nestedKey];
            if (nestedValue) {
                [mutableQueryStringComponents addObjectsFromArray:AFQueryStringPairsFromKeyAndValue((key ? [NSString stringWithFormat:@ % @ [% @] "", key, nestedKey] : nestedKey), nestedValue)]; }}}else if ([value isKindOfClass:[NSArray class]]) {
        NSArray *array = value;
        for (id nestedValue in array) {
            [mutableQueryStringComponents addObjectsFromArray:AFQueryStringPairsFromKeyAndValue([NSString stringWithFormat:@ % @ "[]", key], nestedValue)]; }}else if ([value isKindOfClass:[NSSet class]]) {
        NSSet *set = value;
        for (id obj in[set sortedArrayUsingDescriptors:@[ sortDescriptor ]]) { [mutableQueryStringComponents addObjectsFromArray:AFQueryStringPairsFromKeyAndValue(key, obj)]; }}else {
        [mutableQueryStringComponents addObject:[[AFQueryStringPair alloc] initWithField:key value:value]];
    }
    return mutableQueryStringComponents;
}
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  • ifGET.HEAD.DELETERequest to concatenate parameters tourlBack, ifPUT.POSTRequest, check whether there are Settings firstContent-TypeIf no, use the default valueapplication/x-www-form-urlencodedAnd then concatenate the parameters tohttp bodyIn the
if ([self.HTTPMethodsEncodingParametersInURI containsObject:[[request HTTPMethod] uppercaseString]]) {
    if (query && query.length > 0) {
        mutableRequest.URL = [NSURL URLWithString:[[mutableRequest.URL absoluteString] stringByAppendingFormat:mutableRequest.URL.query ? @ "& % @" : @ "? % @", query]]; }}else {
    if(! query) { query =@ "";
    }
    if(! [mutableRequest valueForHTTPHeaderField:@"Content-Type"]) {
        [mutableRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    }
    [mutableRequest setHTTPBody:[query dataUsingEncoding:self.stringEncoding]];
}
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  • throughrequestgeneratetask
  • 1.Created using serial queuesdtaTaskTo solveiOS8See the following bug for detailsissue 2093
__block NSURLSessionDataTask *dataTask = nil;
url_session_manager_create_task_safely(^{
dataTask = [self.session dataTaskWithRequest:request];

});
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  • totaskAdd the agent
[self addDelegateForDataTask:dataTask uploadProgress:uploadProgressBlock downloadProgress:downloadProgressBlock completionHandler:completionHandler];
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  • In order totaskIdforkeywilldelegatedepositmutableTaskDelegatesKeyedByTaskIdentifier, eachtaskThey have their owndelegate
    • manager > session > task <> delegate > manager(weakTo prevent circular references.
    • managerholdtask.taskanddelegateIt’s bound. It’s equivalent tomanagerIs to havedelegatethe
    • withKVOListening to theAFURLSessionManagerTaskDelegatethedownloadProgressanduploadProgress
    • withKVOListening to theTasktheprogress, will be monitoredcompletedUnitCountandtotalUnitCountAssigned todownloadProgressanduploadProgress
    • Listen to thedownloadProgressanduploadProgressChange, callThe AFURLSessionManagerTaskDelegate downloadProgressBlockanduploadProgressBlockThe callback
  • resume()
    • tasktheresume()Be replaced byaf_resume()
- (void)af_resume {
    NSAssert([self respondsToSelector:@selector(state)], @"Does not respond to state");
    NSURLSessionTaskState state = [self state];
    [self af_resume];
    if(state ! =NSURLSessionTaskStateRunning) {[[NSNotificationCenter defaultCenter] postNotificationName:AFNSURLSessionTaskDidResumeNotification object:self]; }}Copy the code
  • whentaskNotifies when the status changesmanager
- (void)addNotificationObserverForTask:(NSURLSessionTask *)task {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(taskDidResume:) name:AFNSURLSessionTaskDidResumeNotification object:task];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(taskDidSuspend:) name:AFNSURLSessionTaskDidSuspendNotification object:task];
}
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  • managerreleasetaskStatus change broadcast
- (void)taskDidResume:(NSNotification *)notification {
    NSURLSessionTask *task = notification.object;
    if ([task respondsToSelector:@selector(taskDescription)]) {
        if ([task.taskDescription isEqualToString:self.taskDescriptionForSessionTasks]) {
            dispatch_async(dispatch_get_main_queue(), ^{
                [[NSNotificationCenterdefaultCenter] postNotificationName:AFNetworkingTaskDidResumeNotification object:task]; }); }}}Copy the code