WKWebView 清理cookie的坑

自iOS 8之后，WKWebView的高性能使很多开发者逐渐从UIWebView转到WKWebView，从此开启了开发者们对WKWebView又爱又恨的历程，趟过很多坑，我这里就说下清理cookie的坑

• 使用UIWebView时，清理cookie使用NSHTTPCookieStorage单例就行了

//清除cookie
NSHTTPCookie *cookie;  
NSHTTPCookieStorage *storage = [NSHTTPCookieStorage sharedHTTPCookieStorage];  
for (cookie in [storage cookies]){  
  [storage deleteCookie:cookie];  
}

• 到了WKWebView，因为iOS 8并没有提供管理的API,所以只能通过获取沙盒Cookies路径删除

NSString *libraryPath = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES).firstObject;
NSString *cookiesFolderPath = [libraryPath stringByAppendingString:@"/Cookies"];
[[NSFileManager defaultManager] removeItemAtPath:cookiesFolderPath error:nil];

• iOS 9之后，苹果提供了WKWebsiteDataStore相关API

    if (@available(iOS 9.0, *)) {
        [[WKWebsiteDataStore defaultDataStore] removeDataOfTypes:[NSSet setWithObjects:WKWebsiteDataTypeCookies, nil] modifiedSince:[NSDate distantPast] completionHandler:^{

        }];
    }

• 但是各位老铁，如果真的用了上面的代码，会发现，清理cookie变成了概率事件，有时好用有时不好用，所以只能用另一个API

[[WKWebsiteDataStore defaultDataStore] fetchDataRecordsOfTypes:[NSSet setWithObjects:WKWebsiteDataTypeCookies, nil]
                             completionHandler:^(NSArray<WKWebsiteDataRecord *> * _Nonnull records) {
                                 [[WKWebsiteDataStore defaultDataStore] removeDataOfTypes:[NSSet setWithObjects:WKWebsiteDataTypeCookies, nil]
                                               forDataRecords:records
                                            completionHandler:^{
                                                
                                                }                                               
                                            }];
                             }];