How to stop repeitive alerts in WebView runJavascriptAlert OSX - javascript

I've created the below runJavaScriptAlertPanelWithMessage function which displays a javascript alert, however I would like to prevent malicious websites from being able to constantly bring up alerts. I've tried various things but haven't had any luck, so was hoping someone may have an idea on how I can achieve this.
- (void)webView:(WebView *)wv runJavaScriptAlertPanelWithMessage:(NSString *)msg initiatedByFrame:(WebFrame *)frame {
NSString *host = [[NSURL URLWithString:[wv mainFrameURL]] host];
NSString *t = NSLocalizedString(host, #"");
NSString *defaultButton = NSLocalizedString(#"OK", #"");
self.currentJavaScriptAlert = [NSAlert alertWithMessageText:t defaultButton:defaultButton alternateButton:nil otherButton:nil informativeTextWithFormat:msg];
[currentJavaScriptAlert beginSheetModalForWindow:[[frame webView] window] modalDelegate:self didEndSelector:#selector(alertPanelDidEnd:returnCode:contextInfo:) contextInfo:NULL];
}

Related

pass alert from UIWebView to iOS app

I have create an app, which works fine. The only thing i need is to pass the alerts from uiwebview to my iOS app.
i have this alert on my uiwebview
<div id="alerts" class="alerts">
<p class="alert-red">ok. come back again tomorrow, not now.</p>
i want this alert to transfer into my app and make it into an uialertview
UIAlertView *errr = [[UIAlertView alloc]initWithTitle:#"nil" message:#"ok. come back again tomorrow, not now." delegate:self cancelButtonTitle:#"Ok, Got it" otherButtonTitles:nil, nil];
[errr show];
any idea how to achieve this result? do i need NSNotification to listen when this alert show up on uiwebview?
I tried something like this
NSString *theTitle=[webView stringByEvaluatingJavaScriptFromString:#"var targetDiv = document.getElementById('alerts').getElementsByClassName('alert-red')[0];"];
NSLog(#"%#",theTitle);
So I can try to retrieve that message from "alert-red" but doesn't work.
I'm new to javascript and html
This is the typical workaround used to solve this problem:
in your webpage when you want to show this alert, run this javascript code:
window.location = 'custom_action';
then in objc implement shouldStartLoadWithRequest on your controller (and set yourWebView.delegate = yourController)
-(BOOL)webView:(UIWebView *)webView
shouldStartLoadWithRequest:(NSURLRequest *)request
navigationType:(UIWebViewNavigationType)navigationType {
// detect when the webview switches to this custom url
if([[[request URL] absoluteString] isEqualToString: #"custom_action"]) {
UIAlertView *errr = [[UIAlertView alloc]initWithTitle:#"nil" message:#"ok. come back again tomorrow, not now." delegate:self cancelButtonTitle:#"Ok, Got it" otherButtonTitles:nil, nil];
[errr show];
// this prevents the webview from actually trying to load the custom url
return NO;
}
// allow the url to load if its not your custom url
return YES;
}

WKWebview's javascript call returns nil

I'm trying to migrate from using a UIWebview to a WKWebview, and I need to invoke various Javascript functions that live in the webview.
In the UIWebview I have no trouble doing this, but the WKWebview throws an WKErrorDomain Error 4 for any and all calls. I thought it might be a race condition where I was calling functions that didn't exist in the DOM yet, but I added a debug statement to make those same calls once the page loaded and they're not working. I even did a 'document.body.innerHTML' which returned nil when there's clearly content being displayed in the webview.
The twist is that when inspecting the web code via Safari Web Inspector, everything works well and all calls work.
Why and how could this be? I do initialize the WKWebView with a WKWebViewConfiguration so that it'll share cookies across different webviews, so there might be something there, but I'm stumped.
This is how i initialize the WKWebView
WKWebViewConfiguration* config = [[WKWebViewConfiguration alloc] init];
config.processPool = [[WKProcessPool alloc] init];
WKUserContentController* userContentController = WKUserContentController.new;
WKUserScript * cookieScript = [[WKUserScript alloc] initWithSource: #"document.cookie = 'cookie1=value1; domain=blah; path=/;';" injectionTime:WKUserScriptInjectionTimeAtDocumentStart forMainFrameOnly:NO];
[userContentController addUserScript:cookieScript];
config.userContentController = userContentController;
WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectMake(0,0,50,50) configuration:config];
Here's a debugging statement where I log the document's innerHTML into the console log, which prints (nil) instead of the HTML.
NSLog(#"%#", [self.webView evaluateJavaScript:#"document.body.innerHTML" completionHandler:nil]);
WKWebView executes JS async unlike UIWebView; You cannot print like how you are doing..
Try this
[self.webView evaluateJavaScript:#"document.body.innerHTML" completionHandler:^(id result, NSError *error) {
NSLog(#"Error is %#",error);
NSLog(#"JS result %#" ,result);
}];

I would like to export the contents of ios web view as html

I am writing an app for ios to extract information from a webpage, however, the relevant pieces on the page are built by javascript. So when it is loaded by webview, the javascript is executed and the information displays no problem. If I try to load the page into a string by using the following method, the javascript is loaded, but not actually executed, therefore the string has no useful data in it.
NSData *urlData = [NSData dataWithContentsOfURL:[NSURL URLWithString:fullURL]];
NSString *responseString = [[NSString alloc] initWithData:urlData encoding:NSUTF8StringEncoding];
Is there another way besides loading the page into webview and exporting it from there? If not, how do you do that?
I'm not sure if there's another way outside of letting the UIWebView execute the JS and render the page, but if you do end up going this route, you could just grab the HTML of the whole page and pass that to the native end like so:
[dummyWebView stringByEvaluatingJavaScriptFromString:#"document.getElementsByTagName('html')[0].outerHTML;"];
Listening to the window.load event might be better to know when the page has finished going through all the JS
Good luck!
You set delegate to webView: self.webView.delegate = self; and implement UIWebViewDelegate:
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
NSString *html = [webView stringByEvaluatingJavaScriptFromString:#"document.documentElement.outerHTML"];
NSLog(#"html1 = %#", html);
// or use
NSString *html2 = [webView stringByEvaluatingJavaScriptFromString:#"document.body.innerHTML"];
NSLog(#"html2 = %#", html2);
}

Capture (and prevent) alert() modal in UIWebView [duplicate]

<script language="javascript">
alert("Hell! UIWebView!");
</script>
I can see the alert message inside my UIWebView but can I handle this situation?
Update:
I'm loading a web-page into my UIWebView:
- (void)login {
NSString *requestText = [[NSString alloc] initWithFormat: #"%#?user=%#&password=%#", DEFAULT_URL, user.name, user.password]; // YES, I'm using GET request to send password :)
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:requestText]];
[webView loadRequest:request];
}
The target page contain a JS. If user name or password is incorrect this JS show alert.
I have not any access to its sources.
I want to handle it inside my UIWebViewDelegate.
A better solution to this problem is to create a Category for UIWebView for the method
webView:runJavaScriptAlertPanelWithMessage:initiatedByFrame:
So that you can handle the alert event in any way that you'd like. I did this because I don't like the default behavior of UIWebView when it puts the filename of the source in the UIAlertView title. The Category looks something like this,
#interface UIWebView (JavaScriptAlert)
- (void)webView:(UIWebView *)sender runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WebFrame *)frame;
#end
#implementation UIWebView (JavaScriptAlert)
- (void)webView:(UIWebView *)sender runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WebFrame *)frame {
UIAlertView* dialogue = [[UIAlertView alloc] initWithTitle:nil message:message delegate:nil cancelButtonTitle:#"Okay" otherButtonTitles:nil];
[dialogue show];
[dialogue autorelease];
}
#end
This seems to do it:
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
JSContext *ctx = [webView valueForKeyPath:#"documentView.webView.mainFrame.javaScriptContext"];
ctx[#"window"][#"alert"] = ^(JSValue *message) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"JavaScript Alert" message:[message toString] delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
};
}
Note: only tested on iOS 8.
If by "contain a flash" you mean the page you're loading into your web view has an Adobe Flash movie in it, you're out of luck, I'm afraid. Mobile Safari doesn't support Flash, and most likely never will.
In the general case, if you want JavaScript running in a web view to communicate with the native app hosting it, you can load fake URLs (for example: "myapp://alert?The+text+of+the+alert+goes+here."). That will trigger the webView:shouldStartLoadWithRequest:navigationType: delegate method. In that method, inspect the request, and if the URL being loaded is one of these internal communications, trigger the appropriate action in your app, and return NO.

Call javascript - click() in a WebView from Cocoa Objective-C code

In a MacOS X application, I create a Window containing a WebView.
The WebView is initialized on a html page that contains an anchor:
Go To Google.
I would like to click on that link from another class.
It seems clear that a simple javascript code would do the trick: document.getElementById("myLink").click();
So, I wrote that small objective-c code that should do it:
NSString *cmd = #"document.getElementById(\"myLink\").click();";
id result = [[attachedWebView windowScriptObject] evaluateWebScript:cmd];
if ([result isMemberOfClass:[WebUndefined class]]) {
NSLog(#"evaluation of <%#> returned WebUndefined", cmd)
But I can't make it work.
If anybody has an idea, that would really help.
I think it is nothing todo with webview, but just your javascript.
Does it work if you try it in Safari's console? I wouldn't expect it to as you can only click() input elements (buttons) reliably cross-browser. A JQuery click() should work tho.
see How do I programmatically click a link with javascript?
So here is the solution I used.
Created a file: WebAgent.js containing the following code:
function myClick(id) {
var fireOnThis = document.getElementById(id);
var evObj = document.createEvent('MouseEvents');
evObj.initEvent( 'click', true, true );
fireOnThis.dispatchEvent(evObj);
}
And the following code in my objective-c class
// load cmd.js
NSString *path = #"/code/testagent/WebAgent/WebAgent/WebAgent.js";
NSString *jsCode = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
[[self attachedWebView ]stringByEvaluatingJavaScriptFromString:jsCode];
//do the click
NSString * anchorId = #"myId";
NSString *call = [NSString stringWithFormat:#"WebAgent_click('%#')",anchorId];
[[self attachedWebView] stringByEvaluatingJavaScriptFromString:call];
NB: I used this solution to have the JS code in a specific file, as I expect to have more JS code in the future.
Thanks for your help.

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