When working on a Cordova Hybrid app (a cordova app wrapped in a thin layer of native UI) that uses Ionic Web View plugin as the WebView, there was a requirement from the client to have a native button that would load a local testing html file in the main WebView.
Changing the main WebView url in response to a native button, requires editing the
MainViewController.m file, which is the main view in which the WebView lives, and where we can find its reference:
self.webViewEngine exposes the
loadRequest method, which we can call to load any url that we’ve allowed using
allow-navigation tag in
config.xml. Therefor, calling
@"test.html" should be quite straightforward right? Not exactly. Loading
@"test.html" will show a white screen, with no error, even though the file exists in the
www folder right next to
So following my commitment to blog about anything that takes me more than half an hour to solve, you’re now reading this post, which will hopefully save you some time.
According to Ionic docs, the Ionic Web View uses a local HTTP server to serve local files, including the main
index.html. This is different from the default Cordova WebView that loads
index.html with the
file:/// protocol. Under the hood, Ionic Web View engine adds handling of the custom url scheme
ionic://, using WKWebView’s WKURLSchemeHandler.
There’s some tricky logic that goes into resolving different url protocols, including replacing
file:/// protocol. So in order to access local files that are bundled within our
www folder, we’ll use this
ionic:// protocol directly.
This is how to load
test.html into the main Ionic Web View (which in turn can load any local JS / CSS / other resource). You can use this code in
MainViewController.m in the XCode project.
NSURL *url = [NSURL URLWithString:@"ionic://localhost/test.html"] NSURLRequest* appReq = [ NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:20.0 ]; [self.webViewEngine loadRequest:appReq];
We’re creating an
NSURL that points to
ionic://localhost/test.html, then creating an
NSURLRequest with that url and a timeout of 20 seconds, then calling the method
self.webViewEngine (inherited from
Now your new URL should load in the WebView!