iOS WKWebView (NSURLProtocol)攔截js、css，圖片資源

劉小弟

IP屬地: 四川

3.9 2017.01.19 16:11 字?jǐn)?shù) 452

項(xiàng)目地址github：<a >HybirdWKWebVIew</a>

HybridNSURLProtocol

一個(gè)基于WKWebView的hybirde的容器。能攔截所有WKWKWebView的的css,js,png等網(wǎng)絡(luò)請(qǐng)求的demo
NSURLProtocol 子類(lèi)，就可以對(duì) app 內(nèi)所有的網(wǎng)絡(luò)請(qǐng)求進(jìn)行:

[NSURLProtocol registerClass:[HybridNSURLProtocol class]]

可是在 WKWebView 中的請(qǐng)求卻完全不遵從這一規(guī)則，只是象征性+ (BOOL) canInitWithRequest:(NSURLRequest *)request 方法，之后的整個(gè)請(qǐng)求流程似乎就與 NSURLProtocol 完全無(wú)關(guān)了。

使我WKWebView 的一度認(rèn)為請(qǐng)求不遵守NSURLProtocol協(xié)議，所以不走 NSURLProtocol。這個(gè)也是很苦擾我的問(wèn)題。導(dǎo)致我們hybird的容器1.0也是是用UIWebVIew實(shí)現(xiàn)的。

但在蘋(píng)果放在gittub的CustomHTTPProtocol，明顯感覺(jué)到WKWebview的也是遵守NSURLProtocol，要不也不會(huì)走+ (BOOL)canInitWithRequest:(NSURLRequest *)request;后來(lái)一個(gè)每天看博客和gittub的習(xí)慣幫助了我，找到一個(gè)大神的不久前開(kāi)源庫(kù)。

使用了WKBrowsingContextController和registerSchemeForCustomProtocol。通過(guò)反射的方式拿到了私有的 class/selector。通過(guò)kvc取到browsingContextController。通過(guò)把注冊(cè)把 http 和 https 請(qǐng)求交給 NSURLProtocol 處理。

[NSURLProtocol wk_registerScheme:@"http"];
[NSURLProtocol wk_registerScheme:@"https"];

下面直接上源代碼吧

//FOUNDATION_STATIC_INLINE 屬于屬于runtime范疇，你的.m文件需要頻繁調(diào)用一個(gè)函數(shù),可以用static inline來(lái)聲明。在SDWebImage讀取內(nèi)存的緩存也用到這個(gè)聲明。
FOUNDATION_STATIC_INLINE Class ContextControllerClass() {
static Class cls;
if (!cls) {
cls = [[[WKWebView new] valueForKey:@"browsingContextController"] class];
}
return cls;
}

FOUNDATION_STATIC_INLINE SEL RegisterSchemeSelector() {
return NSSelectorFromString(@"registerSchemeForCustomProtocol:");
}

FOUNDATION_STATIC_INLINE SEL UnregisterSchemeSelector() {
return NSSelectorFromString(@"unregisterSchemeForCustomProtocol:");
}

@implementation NSURLProtocol (WebKitSupport)

+ (void)wk_registerScheme:(NSString *)scheme {
Class cls = ContextControllerClass();
SEL sel = RegisterSchemeSelector();
if ([(id)cls respondsToSelector:sel]) {
// 放棄編輯器警告
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
[(id)cls performSelector:sel withObject:scheme];
#pragma clang diagnostic pop
}
}

+ (void)wk_unregisterScheme:(NSString *)scheme {
Class cls = ContextControllerClass();
SEL sel = UnregisterSchemeSelector();
if ([(id)cls respondsToSelector:sel]) {
// 放棄編輯器警告
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
[(id)cls performSelector:sel withObject:scheme];
#pragma clang diagnostic pop
}
}

注冊(cè)后，客戶端所有請(qǐng)求走+ (BOOL)canInitWithRequest:(NSURLRequest *)request。下面是打印的請(qǐng)求的log

+ (BOOL)canInitWithRequest:(NSURLRequest *)request
{
NSLog(@"request.URL.absoluteString = %@",request.URL.absoluteString);
NSString *scheme = [[request URL] scheme];
if ( ([scheme caseInsensitiveCompare:@"http"]  == NSOrderedSame ||
[scheme caseInsensitiveCompare:@"https"] == NSOrderedSame ))
{
//看看是否已經(jīng)處理過(guò)了，防止無(wú)限循環(huán)
if ([NSURLProtocol propertyForKey:KHybridNSURLProtocolHKey inRequest:request])
return NO;
return YES;
}
return NO;
}

Aaron Swartz

request的重寫(xiě)定向，request的重寫(xiě)定向，替換百度知道的log

+ (BOOL)canInitWithRequest:(NSURLRequest *)request
{
NSLog(@"request.URL.absoluteString = %@",request.URL.absoluteString);
NSString *scheme = [[request URL] scheme];
if ( ([scheme caseInsensitiveCompare:@"http"]  == NSOrderedSame ||
[scheme caseInsensitiveCompare:@"https"] == NSOrderedSame ))
{
//看看是否已經(jīng)處理過(guò)了，防止無(wú)限循環(huán)
if ([NSURLProtocol propertyForKey:KHybridNSURLProtocolHKey inRequest:request])
return NO;
return YES;
}
return NO;
}

這里最好加上緩存判斷，加載本地離線文件，這個(gè)直接簡(jiǎn)單的例子。

- (void)startLoading
{
NSMutableURLRequest *mutableReqeust = [[self request] mutableCopy];
//給我們處理過(guò)的請(qǐng)求設(shè)置一個(gè)標(biāo)識(shí)符, 防止無(wú)限循環(huán),
[NSURLProtocol setProperty:@YES forKey:KHybridNSURLProtocolHKey inRequest:mutableReqeust];

//這里最好加上緩存判斷，加載本地離線文件， 這個(gè)直接簡(jiǎn)單的例子。
if ([mutableReqeust.URL.absoluteString isEqualToString:sourIconUrl])
{
NSData* data = UIImagePNGRepresentation([UIImage imageNamed:@"medlinker"]);
NSURLResponse* response = [[NSURLResponse alloc] initWithURL:self.request.URL MIMEType:@"image/png" expectedContentLength:data.length textEncodingName:nil];
[self.client URLProtocol:self didReceiveResponse:response cacheStoragePolicy:NSURLCacheStorageAllowed];
[self.client URLProtocol:self didLoadData:data];
[self.client URLProtocolDidFinishLoading:self];
}
else
{
NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:nil];
self.task = [session dataTaskWithRequest:self.request];
[self.task resume];
}
}

下面是代碼效果圖