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WKWebview javascript works on simulator but doesn't work on device if the view isn't on the screen

I'm using a WKWebview to run javascript scripts.
I am not using JSContext et.al since I need the javascript context to be able to perform XHTTP requests which aren't possible with JSContext alone.
This view is not added to the view hierarchy and I have no interest to do so.
The WKWebview is only used for its ability to run JS code in its engine.
The javascript code is working exactly as expected on the simulator.
The exact same code will also work in the context of certain other applications which I've tested with.
But for some reason in certain applications the WKWebview will not perform the javascript unless the WKWebview is added to the view hierarchy. The following code will work as expected. If removing the #warning code , stops working as expected
-(void)connect {
//TODO: Handle multiple connect calls
WKUserContentController *userContentController = [WKUserContentController new];
[self addScriptMessageHandlersForSocketEvents:userContentController];
NSString *socketFileContent = [self.class socketIOScript];
WKUserScript *socketIOScript = [[WKUserScript alloc] initWithSource:socketFileContent
injectionTime:WKUserScriptInjectionTimeAtDocumentStart
forMainFrameOnly:NO];
[userContentController addUserScript:socketIOScript];
NSString *bridgeJs = [self.class bridgeScript];
WKUserScript *bridgeScript = [[WKUserScript alloc] initWithSource:bridgeJs
injectionTime:WKUserScriptInjectionTimeAtDocumentStart
forMainFrameOnly:NO];
[userContentController addUserScript:bridgeScript];
NSMutableDictionary *d = [NSMutableDictionary new];
for (NSURLQueryItem *item in _parameters) {
d[item.name] = item.value;
}
NSString *params = json(d);
NSString *socketURLScript = [NSString stringWithFormat:#"createSocket(%#,%#);log('created script')",stringify(_url),params];
WKUserScript *createSocket = [[WKUserScript alloc] initWithSource:socketURLScript
injectionTime:WKUserScriptInjectionTimeAtDocumentEnd
forMainFrameOnly:NO];
[userContentController addUserScript:createSocket];
WKWebViewConfiguration * wkconfiguration = [WKWebViewConfiguration new];
wkconfiguration.userContentController = userContentController;
_wv = [[WKWebView alloc] initWithFrame:CGRectMake(0, 0, 0, 0) configuration:wkconfiguration];
#warning REMOVE THIS AND THE WKWebview stops working on some devices (NOT ALL DEVICES) and works in some applications as expected
[[UIApplication sharedApplication].keyWindow addSubview:_wv];
// END REMOVE THIS
_wv.navigationDelegate = self;
dispatch_group_enter(_loadedSemaphore);
[_wv loadHTMLString:#"<h1></h1>" baseURL:nil];
}

did you implement all the delegate methods for WKWebView ?

iOS - Webview - Notify Javascript when an NSNotification is received

I was wondering if anyone knew how to do this. I have a bunch of NSNotifications and I'd like to create listeners in Javascript, embedded in a UIWebView, that will get executed when the NSNotifications are received.
I know this is possible using PhoneGap and the method sendPluginResult, but I was wondering if there was another way of doing it without cordova.
Thanks

Create your listener outside the UIWebView and send the stringByEvaluatingJavaScriptFromString message to your web view.
- (void)registerObserver
{
NSArray *names = [NSArray arrayWithObjects:
#"FirstNotification", #"SecondNotification", #"ThirdNotification", nil];
for (NSString *name in names)
{
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:#selector(notificationReceived:)
name:#"NotificationName"
object:nil];
}
}
- (void)notificationReceived:(NSNotification *notification)
{
NSString *js = [NSString stringWithFormat:
#"notificationReceived('%#');", notification.name];
[self.webView stringByEvaluatingJavaScriptFromString:js];
}

in the call back NSNotification method call this:
[yourwebview stringByEvaluatingJavaScriptFromString:#"methodName()"];
and create that "methodname" in your javascript code

Pushwoosh phonegap plugin, retrieving hwid on ios

I'm using pushwoosh to send push notifications to my ios mobile app. I want to allow users to disable notifications from within the app. The problem I'm having is that the pushwoosh api uses a different device id for ios than it does for android. The device id is created by the plugin using native code. It uses the hardware mac address and applies the md5 algorithm to create a "unique" id that phonegap is calling "hwid"(hardware id). I've found the native, objective c class that does this but I don't know how to access the variable, "hwid", from Javascript.
I've read through the phonegap documentation and have created a plugin that allows me to access native ios classes. My problem is that I don't know objective c and therefore cannot figure out how to return the variable to the callback.
The pushwoosh api requires the device id in order to unregister a device as you can see here:
{
"request":{
"application":"APPLICATION_CODE",
"hwid": "hardware device id"
}
}
I have seen this post and it is not helpful for what I'm trying to accomplish. However, it does show the native code that creates the unique id.
I also found this class that prints the hwid to the console. If I could find a way to access the "hwid" below from my js code I would be all set.
#import "PWRequest.h"
#implementation PWRequest
#synthesize appId, hwid;
- (NSString *) methodName {
return #"";
}
//Please note that all values will be processed as strings
- (NSDictionary *) requestDictionary {
return nil;
}
- (NSMutableDictionary *) baseDictionary {
NSMutableDictionary *dict = [NSMutableDictionary new];
[dict setObject:appId forKey:#"application"];
[dict setObject:hwid forKey:#"hwid"];
NSLog(#"hwid: %#", hwid);
return [dict autorelease];
}
- (void) parseResponse: (NSDictionary *) response {
}
- (void) dealloc {
self.appId = nil;
self.hwid = nil;
[super dealloc];
}
#end
Can someone point me in the right direction? Thanks.

We have just added unregisterDevice method for iOS Phonegap Javascript.
PushNotification.prototype.unregisterDevice = function(success, fail) {
cordova.exec(success, fail, "PushNotification", "unregisterDevice", []);
};
It used to work only for Android, now it is available on iOS as well.
For Phonegap 3.0 please see the newest Pushwoosh plugin repo:
https://github.com/shaders/pushwoosh-phonegap-3.0-plugin
For older Phonegap versions <= 2.9 please see legacy Pushwoosh Phonegap plugin:
https://github.com/shaders/phonegap-cordova-push-notifications/tree/master/iOS
I hope it helps!

I found a work-around for anyone who needs this. Just open up the class "PWRequest.m" in xcode. Add the code below just under "[dict setObject:hwid forKey:#"hwid"];" in the NSMutableDictionary method.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"hwidfile2.txt"];
NSLog(#"From Echo Class File Path: %#", filePath);
NSString *str = hwid;
This will save a text file to your local app directory in which you can access from your Javascript code. For example, you can use this JS code to access and print the hwid to the console. Just call the 'readPwfile(filename)' function, passing in the name of your file as the function argument.
function readPWFile(fileName){
window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function(fileSystem){
fileSystem.root.getFile(fileName, null, gotReadFileEntry, fail);
});
function gotReadFileEntry(fileEntry) {
fileEntry.file(gotFile, fail);
}
function gotFile(file){
//readDataUrl(file);
readAsText(file);
}
function readAsText(file) {
var reader = new FileReader();
reader.onloadend = function(evt) {
console.log('Reading file... hwig Result: '+evt.target.result);
};
reader.readAsText(file);
}
}

Pushwoosh phonegap plugin, retrieving device ID

I'm using the pushwoosh phonegap plugin for push notifications. After successful registration I need to store the device ID that the registration used in the "hwid" parameter so that I can target push notifications that I send with this same device ID. This works great on Android since it seems the phonegap device.uuid is the same ID that the pushwoosh plugin is sending to their servers. However, on ios the device.uuid returns a different ID than what is sent to pushwoosh. I can see from the Xcode console log the hwid that the plugin is sending to pushwoosh but cannot figure out where they are getting this ID from and how to access the same ID within phonegap.
EDIT: I was hoping the getRemoveNotificationStatus function would return this info but it actually returns less than the registerDevice callback.
UPDATE: Ok, from digging through their plugin code I see where they are constructing this ID that they send to their servers. Not sure why this ID isn't accessible through the phonegap plugin since this is the ID that I ultimately need to have in order to target a push notification to the specific device.
Their code:
(NSString *) uniqueDeviceIdentifier{
NSString *macaddress = [self macaddress];
NSString *bundleIdentifier = [[NSBundle mainBundle] bundleIdentifier];
NSString *stringToHash = [NSString stringWithFormat:#"%#%#",macaddress,bundleIdentifier];
NSString *uniqueIdentifier = [self stringFromMD5:stringToHash];
return uniqueIdentifier;
}
- (NSString *) uniqueGlobalDeviceIdentifier{
// >= iOS6 return identifierForVendor
UIDevice *device = [UIDevice currentDevice];
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(#"6.1")) {
if ([device respondsToSelector:#selector(identifierForVendor)] && [NSUUID class]) {
NSUUID *uuid = [device identifierForVendor];
return [uuid UUIDString];
}
}
// Fallback on macaddress
NSString *macaddress = [self macaddress];
NSString *uniqueIdentifier = [self stringFromMD5:macaddress];
return uniqueIdentifier;
}

Are you sure that you need the hwid?
When I use the Pushwoosh Remote API to send push messages to individual devices I target using the "devices" tag and then just supply the deviceToken of the devices I wish to message.
The device token is easily accessible as it's part of the status-return from the plugin (status['deviceToken']).

As I posted here.
I found a work-around for anyone who needs this. Just open up the class "PWRequest.m" in xcode. Add the code below just under "[dict setObject:hwid forKey:#"hwid"];" in the NSMutableDictionary method.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"hwidfile2.txt"];
NSLog(#"From Echo Class File Path: %#", filePath);
NSString *str = hwid;
This will save a text file to your local app directory in which you can access from your Javascript code. For example, you can use this JS code to access and print the hwid to the console. Just call the 'readPwfile(filename)' function, passing in the name of your file as the function argument.
function readPWFile(fileName){
window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function(fileSystem){
fileSystem.root.getFile(fileName, null, gotReadFileEntry, fail);
});
function gotReadFileEntry(fileEntry) {
fileEntry.file(gotFile, fail);
}
function gotFile(file){
//readDataUrl(file);
readAsText(file);
}
function readAsText(file) {
var reader = new FileReader();
reader.onloadend = function(evt) {
console.log('Reading file... hwig Result: '+evt.target.result);
};
reader.readAsText(file);
}
}

Can I handle alert inside UIWebViewDelegate?

<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.