Inject objective c into UIWebView - javascript

I have made a login form in html/javascript to be injected into a UIWebView in my iPhone application. This all works really well and the login works. But when I press the login button it goes to the expected page within that view.
I was wondering if I could inject some objective c or by ways of a javascript do a modalView or dismissView to have upon the login have the page go to the application.
In the Application I have just made the UI of the webpage more user friendly.
So to kind of show what I am asking I have pasted some code.
NSString *myHTML = #"<form action="gotowebsite.com" onSubmit='return !validateLogin();'><input some textfield><input password field>";
Now I am imagining that the dismissal code will go into the onSubmit area.
Am I on a possibly good track??
Cheers Jeff

Implement UIWebViewDelegate in your class and on successful login redirect your page to a url like login://success
when you redirect your page, UIWebview will start loading request and the call the function written below.
- (BOOL)webView:(UIWebView*)webView shouldStartLoadWithRequest:(NSURLRequest*)request navigationType:(UIWebViewNavigationType)navigationType {
//CAPTURE USER LINK-CLICK.
NSURL *url = [request URL];
NSString *urlStr = [url absoluteString];
if([urlStr isEqualToString:#"login://success"]){ //same url which you gave for redirection
[self dismissModalViewControllerAnimated:YES]; // or do whatever you want to do on a successful login
}
return YES;
}

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;
}

send html email that contains javascript within ios app

Am trying to send an html(which javascript tags) email from my ios app. there is no errors but the javascript will not work
my code below:
- (IBAction)sendDirection:(id)sender {
// Email Subject
NSString *emailTitle = #"example subject";
// Email Content
NSString *messageBody = #"<html><head><script>function initialize(){document.getElementById('directions').innerHTML = 'testing';}</script></head><body onload='initialize()'></div><span id='directions'></span></body></html>";
// To address
NSArray *toRecipents = [NSArray arrayWithObject:#"info#example.com"];
MFMailComposeViewController *mc = [[MFMailComposeViewController alloc] init];
mc.mailComposeDelegate = self;
[mc setSubject:emailTitle];
[mc setMessageBody:messageBody isHTML:YES];
[mc setToRecipients:toRecipents];
// Present mail view controller on screen
[self presentViewController:mc animated:YES completion:NULL];
}
Many email clients disable JavaScript to prevent XSS attacks and other vulnerabilities. Your best bet is to stick to plain HTML+CSS, and even then some of the more interesting CSS features may not be available, depending on the client.
It's hard to tell what you're trying to do with JavaScript, but it's best if you keep all programming in Objective-C and use mail composer only for HTML markup.

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.

User Interaction Enabled Javascript

I am writing a Javascript application and am going to wrap it in a native iOS application. I would like to block user interaction on the UIWebView containing the JS app for a second or two following an event.
Normally I would use the self.webView.userinteractionenabled = NO but the event is triggered in Javascript. How can I block the user from interacting with the web view?
Guessing return false on a touch event of some sort? It's scrolling that I want to block.
Thanks!
When the event occurs in your Javascript code you can send a message to the native wrapper by using the following method:
Set up the following UIWebViewDelegate method (don't forget to set the delegate for the UIWebView):
- (BOOL)webView:(UIWebView*)webView shouldStartLoadWithRequest:(NSURLRequest*)request navigationType:(UIWebViewNavigationType)navigationType {
NSURL *url = [request URL];
if ([[url scheme] isEqualToString:#"block"]) {
// do the your blocking code here
return NO;
}
return YES;
}
Now when your event happens, call the delegate method from your javascript code:
window.location.href = "block://";

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