What dose the iframe do?

[djyde]

Hi, WebViewJavascriptBridge is cool. But I have an odd trouble.

There is an ajax request (XHR) in my website. When I inject the WebViewJavascriptBridge js code. The request was broken.

https://github.com/marcuswestin/WebViewJavascriptBridge/blob/master/WebViewJavascriptBridge%2FWebViewJavascriptBridge.js.txt#L18

This is the relevant code.

But what confuse me is, what is the iframe for? It seems that the iframe do nothing in the js code (Only set the src.)

Hope reply soon, thanks.

[guilhermebruzzi]

I have the same problem.

This bridge uses the src attribute to receive the javascript messages.

But for some reason the javascript bridge stops all requests after it receives the message: https://github.com/marcuswestin/WebViewJavascriptBridge/blob/master/WebViewJavascriptBridge/WKWebViewJavascriptBridge.m#L130

Without that line: "[webView stopLoading];" it works. But i don't know the extra impacts of that.

[lbj96347]

@djyde I have been working several days with you.That's very nice. :-)

About the iFrame.WebViewJavascriptBridge uses it for injecting code(sendData or callHandler... to UIWebView/WKWebView.

As @guilhermebruzzi said,the bridge uses the src attribute to receive the javascript messages or send message.What ever UIWebView or WKWebView ,they uses

wvjbscheme://__WVJB_QUEUE_MESSAGE__

But why our code works well in UIWebView but failed in WKWebView? @guilhermebruzzi gave us a key point.

I go deep into code of the bridge.I found these delegate methods in UIWebView and WKWebView.

_UIWebView_

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
    if (webView != _webView) { return YES; }
    NSURL *url = [request URL];
    __strong WVJB_WEBVIEW_DELEGATE_TYPE* strongDelegate = _webViewDelegate;
    if ([_base isCorrectProcotocolScheme:url]) {
        if ([_base isCorrectHost:url]) {
            NSString *messageQueueString = [self _evaluateJavascript:[_base webViewJavascriptFetchQueyCommand]];
            [_base flushMessageQueue:messageQueueString];
        } else {
            [_base logUnkownMessage:url];
        }
        return NO;
    } else if (strongDelegate && [strongDelegate respondsToSelector:@selector(webView:shouldStartLoadWithRequest:navigationType:)]) {
        return [strongDelegate webView:webView shouldStartLoadWithRequest:request navigationType:navigationType];
    } else {
        return YES;
    }
}

_WKWebView_

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    if (webView != _webView) { return; }
    NSURL *url = navigationAction.request.URL;

    NSLog(@"url is %@", url);

    __strong typeof(_webViewDelegate) strongDelegate = _webViewDelegate;

    if ([_base isCorrectProcotocolScheme:url]) {
        if ([_base isCorrectHost:url]) {
            [self WKFlushMessageQueue];
        } else {
            [_base logUnkownMessage:url];
        }
        [webView stopLoading];
    }

    if (strongDelegate && [strongDelegate respondsToSelector:@selector(webView:decidePolicyForNavigationAction:decisionHandler:)]) {
        [_webViewDelegate webView:webView decidePolicyForNavigationAction:navigationAction decisionHandler:decisionHandler];
    } else {
        decisionHandler(WKNavigationActionPolicyAllow);
    }
}

Both of these methods do the same thing.The Author of bridge tried to avoid repeating inject

wvjbscheme://__WVJB_QUEUE_MESSAGE__

(the iFrame) or redundant Javascript actions of the bridge.

In UIWebView,

webView:shouldStartLoadWithRequest:navigationType:

It means : sent before a web view begins loading a frame.That makes sense.

In WKWebView

- webView:decidePolicyForNavigationAction:decisionHandler: 

It means : Decides whether to allow or cancel a navigation.

But

[webView stopLoading]

It canceled all navigation actions including css image loading Javascript new Image() or XMLHttpRequest ... I try to use break point to figure out this.

_If we use WKWebView,we couldn't do network requests with bridge actions together._

I suppose that

[webView stopLoading] 

should be

decisionHandler(WKNavigationActionPolicyCancel)

Because after _WKFlushMessageQueue_ we should do the right thing like UIWebView does,but not stop loading all resource in WKWebView.

@guilhermebruzzi every actions cross

wvjbscheme://__WVJB_QUEUE_MESSAGE__ 

would run

- webView:decidePolicyForNavigationAction:decisionHandler: 

without that line: "[webView stopLoading];" may cause some redundant Javascript actions I guess.

Hope @marcuswestin would see this. :-)

[marcuswestin]

@djyde cheers :)