UIWebView: Can You Disable Javascript?

You can disable Javascript in both mobile Safari and Cocoa's WebView but I can see no means of doing so in UIWebView.

Am I correct?

I ask in relation to this question regarding obtaining the title of page displayed in an UIWebView using Javascript. I had worried that it would fail if Javascript was disabled but it开发者_运维技巧 appears the API does not allow the disabling of Javascript.

If Javascript cannot be deactivated UIWebView,that renders my previous question moot.

There is a way! Using the Content Security Policy which is partially supported in iOS 5.1 and up, and a custom header:

X-WebKit-CSP: script-src none;

You can tell the UIWebKit to not allow javascript on the page entirely. (or selectively only allow script from a specific domain, more information in the spec.

To do this from a server you control, you'll have to modify the response headers for the page to include the X-WebKit-CSP header... To do it from pages that are local (plain text or HTML data on device), you'll have to define and register a custom NSURLProtocol for loading your page, and send the header in your crafted NSHTTPURLResponse:

NSDictionary *headers = [NSDictionary dictionaryWithObjectsAndKeys:
                         @"script-src none",@"X-WebKit-CSP",
                         @"text/html",@"Content-type",
                         encoding,@"Content-encoding",
                         nil];
NSHTTPURLResponse *urlResponse = [[NSHTTPURLResponse alloc] initWithURL:self.request.URL
                                                         statusCode:200
                                                        HTTPVersion:@"1.1"
                                                       headerFields:headers];
[self.client URLProtocol:self didReceiveResponse:urlResponse cacheStoragePolicy:NSURLCacheStorageAllowedInMemoryOnly];

There is no public API to disable Javascript. So it is fairly safe to assume that it won't be disabled.