[AFNetworking]四、AFURLRequestSeri
2019-05-05 本文已影响0人
LNG61
AFHTTPRequestSerializer是用于序列化客户端的请求NSURLRequest。
初始化
- (instancetype)init {
self = [super init];
if (!self) {
return nil;
}
self.stringEncoding = NSUTF8StringEncoding;
self.mutableHTTPRequestHeaders = [NSMutableDictionary dictionary];
self.requestHeaderModificationQueue = dispatch_queue_create("requestHeaderModificationQueue", DISPATCH_QUEUE_CONCURRENT);
// Accept-Language HTTP Header; see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.4
NSMutableArray *acceptLanguagesComponents = [NSMutableArray array];
[[NSLocale preferredLanguages] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
float q = 1.0f - (idx * 0.1f);
[acceptLanguagesComponents addObject:[NSString stringWithFormat:@"%@;q=%0.1g", obj, q]];
*stop = q <= 0.5f;
}];
[self setValue:[acceptLanguagesComponents componentsJoinedByString:@", "] forHTTPHeaderField:@"Accept-Language"];
NSString *userAgent = nil;
userAgent = [NSString stringWithFormat:@"%@/%@ (%@; iOS %@; Scale/%0.2f)", [[NSBundle mainBundle] infoDictionary][(__bridge NSString *)kCFBundleExecutableKey] ?: [[NSBundle mainBundle] infoDictionary][(__bridge NSString *)kCFBundleIdentifierKey], [[NSBundle mainBundle] infoDictionary][@"CFBundleShortVersionString"] ?: [[NSBundle mainBundle] infoDictionary][(__bridge NSString *)kCFBundleVersionKey], [[UIDevice currentDevice] model], [[UIDevice currentDevice] systemVersion], [[UIScreen mainScreen] scale]];
if (userAgent) {
if (![userAgent canBeConvertedToEncoding:NSASCIIStringEncoding]) {
NSMutableString *mutableUserAgent = [userAgent mutableCopy];
if (CFStringTransform((__bridge CFMutableStringRef)(mutableUserAgent), NULL, (__bridge CFStringRef)@"Any-Latin; Latin-ASCII; [:^ASCII:] Remove", false)) {
userAgent = mutableUserAgent;
}
}
[self setValue:userAgent forHTTPHeaderField:@"User-Agent"];
}
// HTTP Method Definitions; see http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html
self.HTTPMethodsEncodingParametersInURI = [NSSet setWithObjects:@"GET", @"HEAD", @"DELETE", nil];
self.mutableObservedChangedKeyPaths = [NSMutableSet set];
NSArray *AFHTTPRequestSerializerObservedKeyPaths = @[NSStringFromSelector(@selector(allowsCellularAccess)), NSStringFromSelector(@selector(cachePolicy)), NSStringFromSelector(@selector(HTTPShouldHandleCookies)), NSStringFromSelector(@selector(HTTPShouldUsePipelining)), NSStringFromSelector(@selector(networkServiceType)), NSStringFromSelector(@selector(timeoutInterval))];
for (NSString *keyPath in AFHTTPRequestSerializerObservedKeyPaths {
if ([self respondsToSelector:NSSelectorFromString(keyPath)]) {
[self addObserver:self forKeyPath:keyPath options:NSKeyValueObservingOptionNew context:AFHTTPRequestSerializerObserverContext];
}
}
return self;
}
- 初始化
Accept-Language - 初始化
User-Agent -
KVO监听allowsCellularAccess、cachePolicy、HTTPShouldHandleCookies、HTTPShouldUsePipelining、networkServiceType、timeoutInterval这几个属性
HTTPHeaderField
- (NSDictionary *)HTTPRequestHeaders {
NSDictionary __block *value;
dispatch_sync(self.requestHeaderModificationQueue, ^{
value = [NSDictionary dictionaryWithDictionary:self.mutableHTTPRequestHeaders];
});
return value;
}
- (void)setValue:(NSString *)value
forHTTPHeaderField:(NSString *)field
{
dispatch_barrier_async(self.requestHeaderModificationQueue, ^{
[self.mutableHTTPRequestHeaders setValue:value forKey:field];
});
}
- (NSString *)valueForHTTPHeaderField:(NSString *)field {
NSString __block *value;
dispatch_sync(self.requestHeaderModificationQueue, ^{
value = [self.mutableHTTPRequestHeaders valueForKey:field];
});
return value;
}
序列化NSURLRequest
- (NSMutableURLRequest *)requestWithMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(id)parameters
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(method);
NSParameterAssert(URLString);
NSURL *url = [NSURL URLWithString:URLString];
NSParameterAssert(url);
NSMutableURLRequest *mutableRequest = [[NSMutableURLRequest alloc] initWithURL:url];
mutableRequest.HTTPMethod = method;
for (NSString *keyPath in AFHTTPRequestSerializerObservedKeyPaths()) {
if ([self.mutableObservedChangedKeyPaths containsObject:keyPath]) {
[mutableRequest setValue:[self valueForKeyPath:keyPath] forKey:keyPath];
}
}
mutableRequest = [[self requestBySerializingRequest:mutableRequest withParameters:parameters error:error] mutableCopy];
return mutableRequest;
}
- 生成一个
NSMutableURLRequest以及设置HTTPMethod - 通过
KVC的方式将mutableObservedChangedKeyPaths赋值给mutableRequest中 - 通过
[self requestBySerializingRequest:mutableRequest withParameters:parameters error:error]返回最终的mutableRequest
接下来看下- (NSURLRequest *)requestBySerializingRequest:withParameters:(id)parameters:error:这个方法的实现：
- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)request
withParameters:(id)parameters
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(request);
NSMutableURLRequest *mutableRequest = [request mutableCopy];
[self.HTTPRequestHeaders enumerateKeysAndObjectsUsingBlock:^(id field, id value, BOOL * __unused stop) {
if (![request valueForHTTPHeaderField:field]) {
[mutableRequest setValue:value forHTTPHeaderField:field];
}
}];
NSString *query = nil;
if (parameters) {
if (self.queryStringSerialization) {
NSError *serializationError;
query = self.queryStringSerialization(request, parameters, &serializationError);
if (serializationError) {
if (error) {
*error = serializationError;
}
return nil;
}
} else {
switch (self.queryStringSerializationStyle) {
case AFHTTPRequestQueryStringDefaultStyle:
query = AFQueryStringFromParameters(parameters);
break;
}
}
}
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 {
// #2864: an empty string is a valid x-www-form-urlencoded payload
if (!query) {
query = @"";
}
if (![mutableRequest valueForHTTPHeaderField:@"Content-Type"]) {
[mutableRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
}
[mutableRequest setHTTPBody:[query dataUsingEncoding:self.stringEncoding]];
}
return mutableRequest;
}
- 首先设置
mutableRequest的头部HTTPHeaderField - 拼接参数，默认使用
AFQueryStringFromParameters拼接，也可以使用自定义拼接参数函数queryStringSerialization - 如果
HTTPMethodsEncodingParametersInURI包含request.HTTPMethod，则将参数拼接到URL的后面，否则设置到mutableRequest的HTTPBody中
拼接参数
NSString * AFQueryStringFromParameters(NSDictionary *parameters) {
NSMutableArray *mutablePairs = [NSMutableArray array];
for (AFQueryStringPair *pair in AFQueryStringPairsFromDictionary(parameters)) {
[mutablePairs addObject:[pair URLEncodedStringValue]];
}
return [mutablePairs componentsJoinedByString:@"&"];
}
NSArray * AFQueryStringPairsFromDictionary(NSDictionary *dictionary) {
return AFQueryStringPairsFromKeyAndValue(nil, dictionary);
}
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;
// Sort dictionary keys to ensure consistent ordering in query string, which is important when deserializing potentially ambiguous sequences, such as an array of dictionaries
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;
}
- 通过该方法来拼接参数，最终得到的结果是
param1=value1¶m2=value2这样的形式。
AFJSONRequestSerializer
AFJSONRequestSerializer是用来序列化格式为json的请求request。
- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)request
withParameters:(id)parameters
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(request);
if ([self.HTTPMethodsEncodingParametersInURI containsObject:[[request HTTPMethod] uppercaseString]]) {
return [super requestBySerializingRequest:request withParameters:parameters error:error];
}
NSMutableURLRequest *mutableRequest = [request mutableCopy];
[self.HTTPRequestHeaders enumerateKeysAndObjectsUsingBlock:^(id field, id value, BOOL * __unused stop) {
if (![request valueForHTTPHeaderField:field]) {
[mutableRequest setValue:value forHTTPHeaderField:field];
}
}];
if (parameters) {
if (![mutableRequest valueForHTTPHeaderField:@"Content-Type"]) {
[mutableRequest setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
}
if (![NSJSONSerialization isValidJSONObject:parameters]) {
if (error) {
NSDictionary *userInfo = @{NSLocalizedFailureReasonErrorKey: NSLocalizedStringFromTable(@"The `parameters` argument is not valid JSON.", @"AFNetworking", nil)};
*error = [[NSError alloc] initWithDomain:AFURLRequestSerializationErrorDomain code:NSURLErrorCannotDecodeContentData userInfo:userInfo];
}
return nil;
}
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:parameters options:self.writingOptions error:error];
if (!jsonData) {
return nil;
}
[mutableRequest setHTTPBody:jsonData];
}
return mutableRequest;
}
- 同样地，先设置
HTTPHeaderField - 将
Content-Type设置为application/json - 将参数
parameters通过NSJSONSerialization转换为NSData，用于HTTPBody
AFNetworking相关文章：
[AFNetworking]一、简介
[AFNetworking]二、AFURLSessionManager
[AFNetworking]三、AFHTTPSessionManager
[AFNetworking]四、AFURLRequestSerialization
[AFNetworking]五、AFURLResponseSerialization
