Using a WKWebView in iOS 8, how can I run a JavaScript function from the native side or otherwise communicate from the native side to JavaScript? There doesn't appear to be a method akin to UIWebView's stringByEvaluatingJavaScriptFromString:.
(I can use - addScriptMessageHandler:name: on the configuration.userContentController object to allow communication from JS to native, but I'm looking for the opposite direction.)
(I filed a Radar for this shortly after asking the question here.)
A new method was just added a few days ago (thanks jcesarmobile for pointing it out):
Add
-[WKWebView evaluateJavaScript:completionHandler:]
http://trac.webkit.org/changeset/169765
The method is available in iOS 8 beta 3 and up. Here's the new method signature:
/* @abstract Evaluates the given JavaScript string.
@param javaScriptString The JavaScript string to evaluate.
@param completionHandler A block to invoke when script evaluation completes
or fails.
@discussion The completionHandler is passed the result of the script evaluation
or an error.
*/
- (void)evaluateJavaScript:(NSString *)javaScriptString
completionHandler:(void (^)(id, NSError *))completionHandler;
Docs are available here: https://developer.apple.com/documentation/webkit/wkwebview/1415017-evaluatejavascript.