Framework for interacting with embedded WebView in iOS application

Last year around the same time I had written a post about Calling Objective-C code from JavaScript in iOS applications . I created a simple framework for it and described how to use it in that post.

Recently I was working on an application that required WebView to be embedded in the same View Controller along with other native iOS controls. I decided to use the above framework, but knew that  my ViewController class will have to extend WebViewController class of the framework. Though I could have done that, I thought separating the functionality of UIWebViewDelegate from the WebViewController would be a better design. So I replaced WebViewController with WebViewDelegate which implements UIWebViewDelegate protocol. I also removed getInitialPageName method from WebViewInterface.h . So here are the files in the new framework – Continue reading “Framework for interacting with embedded WebView in iOS application”

Calling Objective-C code from JavaScript in iOS applications

In the last post I described how to Create iOS Application with HTML User Interface . In this post I am going to describe how to access Objective-C code from JavaScript running in the WebView. It is not as easy as it is in Android. There is no direct API in UIWebView to call native code, unlike in Android which provides WebView.addJavascriptInterface function.

However, there is a work-around. We can intercept each URL before it is being loaded in the WebView. So to call the native code, we will have to construct a URL and pass method name and argument as part of the URL. We then set this URL to window.location in the JavaScript and intercept it in our ViewController.
However most examples I have seen (including PhoneGap) create an instance of iframe and set its source to the URL –
Continue reading “Calling Objective-C code from JavaScript in iOS applications”