WKWebView xmlhttprequest with file url

Question

I am migrating from UIWebView to WKWebView with my local HTMLs in the app documents folder. I can load the index page with all css and js files, but every ajax call (xmlhttprequest) fails because of allowed-access-origin.

I don´t want to use a webserver in my application, because I think it would be oversized. How can I make it possible? The app is a simple HTML5 application for an in house app. The device can´t get online or anything so security could be disabled completly.

Answer 1

This solved my problem:

let config = WKWebViewConfiguration()
config.userContentController = contentController
config.preferences.setValue(true, forKey: "allowFileAccessFromFileURLs")
webView = WKWebView(frame: .zero, configuration: config)
webView.uiDelegate = self
webView.navigationDelegate = self
view = webView

Answer 2

For those who came though SO to find this topic:

This isn't official to turn off the security in WKWebView, but we could use the private API to allow this just like this guy did for the Cordova project: cordova-plugin-wkwebviewxhrfix

The clue is to create the configuration for the WebView and set the allowFileAccessFromFileURLs property.

WKWebViewConfiguration* configuration = originalImpSend(_self, selector, settings);

// allow access to file api
@try {
    [configuration.preferences setValue:@TRUE forKey:@"allowFileAccessFromFileURLs"];
}
@catch (NSException *exception) {}

@try {
    [configuration setValue:@TRUE forKey:@"allowUniversalAccessFromFileURLs"];
}
@catch (NSException *exception) {}

return configuration;

But as I mentioned this is the private API and it could be a reason to reject your application in Apple's App Review. If you want to publish your app in App Store, please consider to run some lightweight HTTP server instead of violate overall security of the web view. Example: GCDWebServer.