NSCachedURLResponse返回对象，但UIWebView不解释内容 [英] NSCachedURLResponse returns object, but UIWebView does not interprets content

问题描述

我正在向UIWebView发送请求。加载的网页上有AJAX调用。我需要分析AJAX流量，以确定用户是否登录。为此，我在AppDelegate中安装了一个NSURLCache：

I am sending a request to a UIWebView. There are AJAX-calls on the loaded webpage. I need to analyze the AJAX-traffic in order to determinate, if the user is logged in or not. For doing this I installed a NSURLCache in the AppDelegate:

MYURLCache *cache = [[MYURLCache alloc] init];
[NSURLCache setSharedURLCache:cache];

此MYURLCache类正确接收通过webview运行的流量。我只能终止AJAX调用。然后我产生了一个自己的AJAX调用请求。这个返回来自网络服务器的完美回复。所以现在要做的最后一步是构建NSCachedURLResponse返回对象。我也管理过这个，但是webview在返回对象时什么都不做。如果我只返回nil，则WebView会加载所有内容（nil是NSURLCache的消息，没有任何内容被缓存，因此webview应该开始自己加载）。

This MYURLCache-class correctly receives the traffic that runs through the webview. I can terminate the AJAX-calls only. I then spawn an own request of the AJAX-calls. This one returns the perfectly fine response from the webserver. So the last step to do now is constructing the NSCachedURLResponse return object. I also managed this, but the webview simply does nothing when returning the objects. If I return just nil, the WebView loads everything fine (nil is the message for the NSURLCache, that nothing is cached, so the webview should start to load it on its own).

- (NSCachedURLResponse *)cachedResponseForRequest:(NSURLRequest *)request {
    if ([[[request URL] absoluteString] rangeOfString:@"/ajax/"].location == NSNotFound) {
        return nil;
    } else {

    ASIHTTPRequest *asirequest = [ASIHTTPRequest requestWithURL:[request URL]];
    [asirequest setValidatesSecureCertificate:NO];
    [asirequest startSynchronous];
    NSError *error = [asirequest error];
    NSData* data = [[asirequest responseString] dataUsingEncoding:NSUTF8StringEncoding];

    // Create the cacheable response
    NSURLResponse *urlresponse = [[NSURLResponse alloc] initWithURL:[request URL] MIMEType:@"application/json" expectedContentLength:[data length] textEncodingName:@"UTF-8"];
    NSCachedURLResponse *cachedResponse = [[NSCachedURLResponse alloc] initWithResponse:urlresponse data:data];

    NSLog(@"cachedResponse %@", cachedResponse);
    NSLog(@"cachedResponse data %@", [[NSString alloc] initWithData:[cachedResponse data] encoding:NSUTF8StringEncoding]);

    return cachedResponse;
}  

return nil;
}

推荐答案

我找到了一个解决方案问题...我认为这与丢失的标题有关。

I found one solution to this problem... I think it has got something to do with the headers that were missing.

如果我更换

NSURLResponse *urlresponse = [[NSURLResponse alloc] initWithURL:[request URL] MIMEType:@"application/json" expectedContentLength:[data length] textEncodingName:@"UTF-8"];
NSCachedURLResponse *cachedResponse = [[NSCachedURLResponse alloc] initWithResponse:urlresponse data:data];

使用

NSHTTPURLResponse *urlresponse = [[NSHTTPURLResponse alloc] initWithURL:request.URL statusCode:200 HTTPVersion:@"1.1" headerFields:nil];
NSCachedURLResponse *cachedResponse = [[NSCachedURLResponse alloc] initWithResponse:urlresponse data:data];

整个过程都有效。此答案另外建议了请求的附加自定义标头。 https://stackoverflow.com/a/15234850/274518

The whole thing works. This answer in addition suggested the additional custom header of the request. https://stackoverflow.com/a/15234850/274518

NSDictionary *headers = @{@"Access-Control-Allow-Origin" : @"*", @"Access-Control-Allow-Headers" : @"Content-Type"};
NSHTTPURLResponse *urlresponse = [[NSHTTPURLResponse alloc] initWithURL:request.URL statusCode:200 HTTPVersion:@"1.1" headerFields:headers];

在我的情况下，我不需要它。

In my case I did not needed it.

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