Submit a form in UIWebView

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;
}

Answer 2

If I understood your problem correctly, I think following steps will help you to provide the solution.

1. In the action of form, you need to write the URL to the web service.
2. In your form, the name of the input field should be matched with the name of the parameters expected for the web service.
3. In your first UIWebView Navigation control, Create the object of screen having second UIWebView and set the response of the web service to the instance member of the object.
4. In your first UIWebView Navigation control, you need to write
   [self presentModalViewController:webView2Object animated:YES];
5. In the screen of having webView2, parse the response before loading the second UIWebView. and inject it with the displayed page using javascript.