feat(android): webview injectEventBindings method for external pages

[m1ga]

• in the last "to arrow function" change on parameter was missed causing it the return an error.

• Adding injectEventBindings to the Android webview so you don't have to run a custom evalJS script yourself in the app to inject the event bindings into external pages.

• minified bindings.js.min again

I still keep the example in the docs if you want to add it manually in case you'll need to make changes (but with less code!). For iOS it is not needed since you can use window.webkit.messageHandlers.yourHandlerName.postMessage... to communicate with the app right away. The manual evalJS code could be used for iOS too!

var win = Ti.UI.createWindow();

var btn = Ti.UI.createButton({
	title: "add"
});
var webview = Ti.UI.createWebView({
	url: "https://example.com"
});

win.add([webview, btn]);
win.open();

btn.addEventListener('click', function(e) {
	webview.injectEventBindings();
});

Before

After clicking the button:

Then you can add other scripts that will fire Ti.App.fireEvents() to your page.

[cb1kenobi]

Parity is important. If iOS uses addScriptMessageHandler(), then either Android should match or we should deprecate addScriptMessageHandler() and add injectEventBindings() to iOS and have addScriptMessageHandler() call it so we don't break backwards compatibility.

[m1ga]

Parity would be good. I just didn't know how to integrate the injectEventBindings() in ObjectivC 😊 That's why I wanted to keep the evalJS example since that is working on both platforms. window.webkit.messageHandlers.yourHandlerName is not available in the Android webview so we can't directly map that.

The default Ti way to communicate from webview -> app is still Ti.App.fireEvent and that is cross-platform. The docs were just always wrong saying that you can't use it with external URL, you could always inject that code with evalJS (or if it is your external page: just put the file on your server and load it right away) 😄

I'll try to see if I can add the iOS part!

[cb1kenobi]

Wow, this PR is looking good! We can dive into the iOS stuff during our meeting. Great job!

[m1ga]

🤔 I broke it after merging master....strange. Master is still building fine, this PR is failing. Checking at the moment.

edit: fixed. Code was in there twice