as the iPhone SDK comes with a rather dysfunctional NSURLCache — Apple suggests to implement it from scratch yourself in the code examples about caching — I went for just this.
Until I came across the [NSKeyedUnarchiver unarchiveObjectWithData:...] not restoring userInfo, storagePolicy and data of NSCachedURLResponse.
Couldn’t believe it and spent almost the whole day verifying that the error is not within my code but really the unarchiver treats those fields transient.
See yourself:
1-(void)testiPhoneSDK312NSKeyedArchiver
2{
3// prepare a NSCachedURLResponse
4 NSCachedURLResponse *src = nil;
5 {
6 NSURL *i_url = [NSURL URLWithString:@"http://www.url.example/path/file.html"];
7 NSString *i_mime = @"text/html";
8 NSInteger expectedContentLength = 112;
9 NSString *i_encoding = @"iso-8859-2";
10
11 NSURLResponse *i_response = [[NSURLResponse alloc] initWithURL:i_url
12 MIMEType:i_mime
13 expectedContentLength:expectedContentLength
14 textEncodingName:i_encoding];
15 NSData *i_data = [@"Hello, world!" dataUsingEncoding:NSISOLatin2StringEncoding];
16 NSURLCacheStoragePolicy i_storage = NSURLCacheStorageAllowed;
17 NSDictionary *i_userInfo = [NSDictionary dictionaryWithObject:
18 [NSDate dateWithTimeIntervalSince1970:13] forKey:@"era"];
19
20 NSCachedURLResponse *src = [[NSCachedURLResponse alloc] initWithResponse:i_response
21 data:i_data
22 userInfo:i_userInfo
23 storagePolicy:i_storage];
24
25// ensure it's all in place:
26 STAssertEqualObjects(i_url, src.response.URL, @"");
27 STAssertEqualObjects(i_mime, src.response.MIMEType, @"");
28 STAssertEquals((int)expectedContentLength, (int)src.response.expectedContentLength, @"");
29 STAssertEqualObjects(@"file.html", src.response.suggestedFilename, @"");
30 STAssertEqualObjects(i_encoding, src.response.textEncodingName, @"");
31
32 STAssertEqualObjects(i_data, src.data, @"");
33 STAssertEqualObjects(i_userInfo, src.userInfo, @"");
34 STAssertEquals( 0u, src.storagePolicy, @"");
35 }
36
37// archive + unarchive:
38 NSCachedURLResponse *dst = [NSKeyedUnarchiver unarchiveObjectWithData:
39 [NSKeyedArchiver archivedDataWithRootObject:src]];
40
41// check whether src == dst
42 STAssertEqualObjects(src.response.URL, dst.response.URL, @"");
43 STAssertEqualObjects(src.response.MIMEType, dst.response.MIMEType, @"");
44 STAssertEquals(src.response.expectedContentLength, dst.response.expectedContentLength, @"");
45 STAssertEqualObjects(src.response.suggestedFilename, dst.response.suggestedFilename, @"");
46 STAssertEqualObjects(src.response.textEncodingName, dst.response.textEncodingName, @"");
47
48// !!!!!!!!!!
49// sad information loss after unarchiving:
50 STAssertNil( dst.data, @"" );
51 STAssertNil( dst.userInfo, @"" );
52 STAssertEquals( 2u , dst.storagePolicy, @"" );
53}When my NSURLCache replacement is ready I think about publishing it a github — interested anyone?