Question

I have a form in the UIWebView to interact with a web service, when I submit the form, the data gets sent to a web service and it will return the result to another UIWebView. The two UIWebViews are under a navigation controller, so when the use submits the form, it slides to another view to display the result. Can anyone point me out how I can achieve this? What do I fill in the “action” attribute in the form element? How can I get the user input back to the application so I can use the web service? I am new to this field, any help will be appreciated. Thanks!

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Update:

Is there a way to save form data from web view back to my program? I think it’s better to save form data back to the program (i.e. store params into nsstring) when I click submit button, and then start querying web service.

Answer 1

You can use the

stringByEvaluatingJavaScriptFromString

function for firing a javascript method from objective c and get a return value from that method.

For example

//Calling the getTheUsername in the javascript.
NSString *userName = [yourWebView stringByEvaluatingJavaScriptFromString:@"getTheUsername()"];

and in javascript

//Method in javascript
function getTheUsername()
{
return userNameVariable;
}

And I doubt that here you may wanna do vice-versa (Call obj-c method from javascript). This cannot be done directly here is the work around.

Set a UIWebViewDelegate, and implement the method webView:shouldStartLoadWithRequest:navigationType:. In your JavaScript code, navigate to some fake URL that encodes the information you want to pass to your app, like, say:
window.location = “someLink://yourApp/form_Submitted:param1:param2:param3”;
In your delegate method, look for these fake URLs, extract the information you need, take whatever action is appropriate, and return NO to cancel the navigation.

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{

    NSLog(@"%@",[[request URL] query]);

    return YES;
}