Call Objective C method from JavaScript with parameter

Question

I succeed to call a Objective C method from a JavaScript method using the following

///javascript

    function hi()
     {
     CallNKitAction("callFromJavascript className=TestCarouselViewController&index="+index);   
     }
            hi();
////objective c

-(void)callFromJavascript
{



 NSLog(@"Before:%f",refToSelf.carouselView.alpha);
 [UIView beginAnimations:nil context:nil];
 [UIView setAnimationDuration:0.6f];
 refToSelf.carouselView.alpha=0.0f;
 [UIView commitAnimations];
 NSLog(@"After:%f",refToSelf.carouselView.alpha);

}

but I don't know how to call with a parameter. Can anyone help?

Michael Kessler · Accepted Answer · 2010-07-18 10:59:02Z

2

Here is some code sample (inside the Objective-C):

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
    NSString *url = [[request URL] absoluteString];

    static NSString *urlPrefix = @"myApp://";

    if ([url hasPrefix:urlPrefix]) {
        NSString *paramsString = [url substringFromIndex:[urlPrefix length]];
        NSArray *paramsArray = [paramsString componentsSeparatedByString:@"&"];
        int paramsAmount = [paramsArray count];

        for (int i = 0; i < paramsAmount; i++) {
            NSArray *keyValuePair = [[paramsArray objectAtIndex:i] componentsSeparatedByString:@"="];
            NSString *key = [keyValuePair objectAtIndex:0];
            NSString *value = nil;
            if ([keyValuePair count] > 1) {
                value = [keyValuePair objectAtIndex:1];
            }

            if (key && [key length] > 0) {
                if (value && [value length] > 0) {
                    if ([key isEqualToString:"index"]) {
                        // Use the index...
                    }
                }
            }
        }

        return NO;
    }
    else {
        return YES;
    }
}

Inside JS:

location.href = 'myApp://index=10';

answered Jul 18, 2010 at 10:59

Michael Kessler

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5 Comments

Rony Over a year ago

hi...thanks for replay...i tried your code...but the delegate does not fire....although i implement uiwebviewdelegate....

Michael Kessler Over a year ago

Have you 'told' the web view that your view controller is its delegate? Add the next line: webView.delegate = self; in your viewDidLoad method...

Michael Kessler Over a year ago

Or connect the delegate of the webView to your view controller in Interface Builder (if you use Interface Builder)...

Rony Over a year ago

yeap i did it...there was no prob with this as u think...i think as i am using NimbleKit...i should go through other approach..ok..thanks u a lot..i solve the prob... :)

Michael Kessler Over a year ago

Probably this is the reason. I believe that NimbleKit does exactly the same as I've posted here.

Brad Larson · Accepted Answer · 2012-07-19 12:39:04Z

2

Noticing that this is unanswered - I have a little project that simplifies the calling of Objective-C from UIWebViews.

It provides a small Javascript function to invoke the Objective-C and a class (called KPWebViewInterceptor) that sits between your WebView and ViewController.

You can read about it and download from: https://github.com/dannywartnaby/KPWebViewInterceptor

edited Jul 19, 2012 at 12:39

Brad Larson

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answered Aug 15, 2010 at 12:52

dannywartnaby

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Comments

cutsoy · Accepted Answer · 2010-07-18 10:18:19Z

0

You'll have to do that with the UIWebViewDelegate. You probably already have a UIWebView, the only thing you have to do is to check out this delegate-method:

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

Source: http://developer.apple.com/iphone/library/documentation/uikit/reference/UIWebViewDelegate_Protocol/Reference/Reference.html

answered Jul 18, 2010 at 10:18

cutsoy

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1 Comment

Rony Over a year ago

hi...thanks for so quick replay....can u say more details?? i want to pass the "index" value from javascript to obj c.. can u give sample code of what u want to say??

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