问题:我有 NSURLProtocol 的子类,但NSURLRequest
返回的+canonicalRequestForRequest:
或返回的请求-connection:willSendRequest:redirectResponse:
从未传递给我的 URL 协议实例。
详细信息:在我的子类中NSURLProtocol
,我实现了+canonicalRequestForRequest:
向请求添加 HTTP 标头的方法。标头已成功添加,但-startLoading
在我的 URL 协议上调用时,self.request
不包含该标头。
此外,当connection:willSendRequest:redirectResponse:
在 的委托上调用时,NSURLConnection
该方法返回的任何请求也永远不会到达我的 URL 协议实例。
我认为问题在于在initWithRequest:cachedResponse:client:
之前调用+canonicalRequestForRequest:
或被connection:willSendRequest:redirectResponse:
调用,并且来自这两种方法的结果请求在它被alloc
/之后永远不会传递给我的 URL 协议实例init
。
这是 Apple 的 URL 加载系统中的错误吗?有解决方法吗?难道我做错了什么?
2014 年 4 月 6 日更新
这是一些示例代码。我设置了 2 个标题:一个在-[APViewController connection:willSendRequest:redirectResponse:]
call 中X-WillSendRequestTest
,另一个在+[APURLProtocol canonicalRequestForRequest:]
. 两者都不是NSURLRequest
通过调用self.request
within获取的-[APURLProtocol startLoading]
。
APViewController.m(NSURLProtocol 的代理)
- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)redirectResponse {
NSLog(@"Will send request: %@", request);
NSMutableURLRequest *newRequest = [request mutableCopy];
// This header will not be in self.request when fetched within the -[APURLProtocol start loading] method.
[newRequest setValue:@"12345" forHTTPHeaderField:@"X-WillSendRequestTest"];
NSLog(@"New request: %@", newRequest);
return newRequest;
}
APURL协议.m
@interface APURLProtocol () <NSURLConnectionDelegate, NSURLConnectionDataDelegate>
// Private properties
@property (nonatomic, strong) NSURLConnection *connection;
@end
@implementation APURLProtocol
#pragma mark -
#pragma mark Init methods
- (id)initWithRequest:(NSURLRequest *)request cachedResponse:(NSCachedURLResponse *)cachedResponse client:(id<NSURLProtocolClient>)client {
NSLog(@"%@", NSStringFromSelector(_cmd));
if ((self = [super initWithRequest:request cachedResponse:cachedResponse client:client])) {
}
return self;
}
#pragma mark -
#pragma mark dealloc
- (void)dealloc {
NSLog(@"%@", NSStringFromSelector(_cmd));
[_connection cancel];
}
#pragma mark -
#pragma mark Inherited class methods
+ (BOOL)canInitWithRequest:(NSURLRequest *)request {
NSLog(@"%@ %@", NSStringFromSelector(_cmd), request);
id requestIsHandled = [self propertyForKey:kAPURLProtocolHandledRequest inRequest:request];
if (requestIsHandled == nil
&& ([request.URL.scheme caseInsensitiveCompare:@"http"] == NSOrderedSame
|| [request.URL.scheme caseInsensitiveCompare:@"https"] == NSOrderedSame
|| [request.URL.scheme caseInsensitiveCompare:@"ftp"] == NSOrderedSame)) {
NSLog(@"YES");
return YES;
}
NSLog(@"NO");
return NO;
}
+ (NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request {
NSLog(@"%@", NSStringFromSelector(_cmd));
NSMutableURLRequest *newRequest = [request mutableCopy];
// This header will not be in self.request when fetched within the -[APURLProtocol start loading] method.
[newRequest setValue:@"12345" forHTTPHeaderField:@"X-CanonicalRequestTest"];
return newRequest;
}
+ (BOOL)requestIsCacheEquivalent:(NSURLRequest *)aRequest toRequest:(NSURLRequest *)bRequest {
NSLog(@"Request is cache equivalent:");
NSLog(@"Request 1: %@", aRequest);
NSLog(@"Request 2: %@", bRequest);
return YES;
}
#pragma mark -
#pragma mark Inherited instance methods
- (void)startLoading {
NSLog(@"%@. Request: %@", NSStringFromSelector(_cmd), self.request);
NSMutableURLRequest *newRequest = [[self request] mutableCopy];
[[self class] setProperty:@"" forKey:kAPURLProtocolHandledRequest inRequest:newRequest];
[self.connection cancel];
self.connection = [[NSURLConnection alloc] initWithRequest:newRequest
delegate:self
startImmediately:YES];
}
@end
NSURLRequest+test.m(类扩展NSURLRequest的描述)
警告:不要在家里这样做。不要使用类别覆盖方法或属性。这仅用于快速调试目的。
@implementation NSURLRequest (test)
- (NSString *)description {
NSString *dataString = [[NSString alloc] initWithData:self.HTTPBody encoding:NSUTF8StringEncoding];
return [NSString stringWithFormat:@"%@: %p {URL: %@, Method: %@, Headers: %@, Data: %@",
NSStringFromClass([self class]), self, self.URL, self.HTTPMethod, [self allHTTPHeaderFields], dataString];
}
@end