From 597a70a8b667307d7bd2722c639bf5cd672a7260 Mon Sep 17 00:00:00 2001
From: Tony Li <crazygemini.lee@gmail.com>
Date: Mon, 25 Nov 2013 14:21:42 +0800
Subject: [PATCH] Add HTTP header filter to pick headers for downloading
 request

---
 SDWebImage/SDWebImageDownloader.h | 8 ++++++++
 SDWebImage/SDWebImageDownloader.m | 9 ++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/SDWebImage/SDWebImageDownloader.h b/SDWebImage/SDWebImageDownloader.h
index 399db45a..93f2404b 100644
--- a/SDWebImage/SDWebImageDownloader.h
+++ b/SDWebImage/SDWebImageDownloader.h
@@ -58,6 +58,14 @@ typedef void(^SDWebImageDownloaderCompletedBlock)(UIImage *image, NSData *data,
 
 + (SDWebImageDownloader *)sharedDownloader;
 
+/**
+ * Set filter to pick headers for downloading image HTTP request.
+ *
+ * This block will be invoked for each downloading image request, returned
+ * NSDictionary will be used as headers in corresponding HTTP request.
+ */
+@property (nonatomic, strong) NSDictionary *(^headersFilter)(NSURL *url, NSDictionary *headers);
+
 /**
  * Set a value for a HTTP header to be appended to each download HTTP request.
  *
diff --git a/SDWebImage/SDWebImageDownloader.m b/SDWebImage/SDWebImageDownloader.m
index 063056fe..abdf3afa 100644
--- a/SDWebImage/SDWebImageDownloader.m
+++ b/SDWebImage/SDWebImageDownloader.m
@@ -120,7 +120,14 @@ static NSString *const kCompletedCallbackKey = @"completed";
         NSMutableURLRequest *request = [NSMutableURLRequest.alloc initWithURL:url cachePolicy:(options & SDWebImageDownloaderUseNSURLCache ? NSURLRequestUseProtocolCachePolicy : NSURLRequestReloadIgnoringLocalCacheData) timeoutInterval:15];
         request.HTTPShouldHandleCookies = NO;
         request.HTTPShouldUsePipelining = YES;
-        request.allHTTPHeaderFields = wself.HTTPHeaders;
+        if (wself.headersFilter)
+        {
+            request.allHTTPHeaderFields = wself.headersFilter(url, [wself.HTTPHeaders copy]);
+        }
+        else
+        {
+            request.allHTTPHeaderFields = wself.HTTPHeaders;
+        }
         operation = [SDWebImageDownloaderOperation.alloc initWithRequest:request options:options progress:^(NSUInteger receivedSize, long long expectedSize)
         {
             if (!wself) return;