I have this NSURL like so:
NSURL *url = [NSURL URLWithString:#"http://jamessuske.com/isthedomeopen/isthedomeopenGetData.php"];
and it works fine when I am connected to the internet. But if I am not (or if the user has no signal) I would want an UIAlertView to appear. I tried the following code below (with and without the if statement) but my app crashes.
if(!url){
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Test Message"
message:#"This is a test"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
[alert release];
}
What Am I doing wrong?
What I mean by crashing, I mean my app opens and does not get the data from the URL. I do not see any errors, I just get brought to a page with this highlighter:
Thread 6
com.app.root.default-priority
- 0 ucol_getVersion
Next to it is a window with this hightlighted
0x17bbd32: movl 204(%ecx), %edx Thread 6: EXC_BAD_ACCESS (code=2 address=0xcc)
What you are doing only checks if the object url is a NULL pointer or not. If you want to check if a user has internet connection, I would recommend trying the Reachability classes, which can be found easily online. This one is very useful for me.
it is recommended to check the Internet availability if you are developing the app with internet connection requirement by the Apple and they are also providing the .h and .m files namely Reachability.h and Reachability.m so please download that files and import to your projects and there is a parameter named "internetConnectionStatus" and by that values use the below alert
if (internetConnectionStatus == NotReachable)
{
UIAlertView *responseAlert = [[UIAlertView alloc] initWithTitle:#"Network Error"
message:#"This application requires network connectivity."
delegate:self
cancelButtonTitle:#"Exit"
otherButtonTitles:#"Continue", nil];
[responseAlert show];
}
else
{ //do other stuff here
}
you can find the reachability files Here and you can use any Reachability files from github
ThnQ
Related
This web view failed error showing the alert popup even when it is loading the website. I believe I need to delay this method in order for it to work.What will be the best method for doing this?
- (void)webView:(UIWebView *)webViewfail didFailLoadWithError:(NSError *)error
{
if([webViewfail isEqual:webview]) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Connection Failed" message:#"Check your Internet connection before refreshing."
delegate:webview
cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
}
}
Here is how I am loading the website
- (void)viewDidLoad
{
[webview loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://www.blabla.com"]]];
}
The problem is most likely an error -999 which generally happens when something from the webpage does not load correctly or a user tries to navigate back while the page is still loading. After some research here's what I found and used to keep the NetworkAlert from poping up every time but still popping up when there is no network.
-(void)webView:(UIWebView *)webBlog didFailLoadWithError:(NSError *)error{
if ([error code] != -999) {
NSLog(#"Could not load the dumb webPage");
//show error alert, etc.
[self showNoNetworkAlert];
}else{
NSLog(#"Could not load the dumb web page...just might blame user!");
}
}
- (void) showNoNetworkAlert{
UIAlertView *baseAlert = [[UIAlertView alloc]
initWithTitle:#"No Network" message:#"A network connection is required. Please verify your network settings and try again."
delegate:nil cancelButtonTitle:nil
otherButtonTitles:#"Dismiss", nil];
[baseAlert show];
}
Hope this helps someone...
Looking for some help again...
I've currently got 2 sections of my app that need internet connection, 1 is a photo gallery through Flickr and the other a Twitter Feed, I was wondering if this is the correct code for the UIAlertView... I can get it working from a button but thats all!
{
-(void)didTap_roundedRectButton1:(id)sender forEvent:(UIEvent *)event {
UIAlertView *alertView = [[UIAlertView alloc] init];
alertView.title = #"You are not connected to the Internet!";
alertView.message = #"Please check your connection and try again...";
[alertView addButtonWithTitle:#"Ok"];
[alertView show];
[alertView release];
}
i think you need to use this example as i have used it to check is there any network is available and device is connected to any one of the network it is alos available on the apple's developer example site
example link is this
You should try this:
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"You are not connected to the Internet!"
message:#"Please check your connection and try again..."
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles: nil];
[alertView show];
[alertView release];
and can you post the code how do you create the UIButton?
I am showing alertViews when Location manager unable to find current location. I did it like this
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
[manager stopUpdatingLocation];
switch([error code])
{
case kCLErrorNetwork: // general, network-related error
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error" message:#"Please check your network connection or that you are not in airplane mode" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil, nil];
[alert show];
[alert release];
}
break;
case kCLErrorDenied:{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error" message:#"User has denied to use current Location " delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil, nil];
[alert show];
[alert release];
}
break;
default:
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error" message:#"Unknown network error" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil, nil];
[alert show];
[alert release];
}
break;
}
}
My problem is locationManager didFailWithError method get called repeatedly. So my alertviews repeatedly display.
How can I solve this issue?
Apple documentation states:
If the location service is unable to retrieve a location right away,
it reports a kCLErrorLocationUnknown error and keeps trying. In such a
situation, you can simply ignore the error and wait for a new event.
If the user denies your application’s use of the location service,
this method reports a kCLErrorDenied error. Upon receiving such an
error, you should stop the location service.
So you might skip some cases where you stop updating and show the alert, especially the default case.
A good start for error messages that can be triggered by an ongoing background process - like the location manager - is to store the reference to the UIAlertView. When the delegate receives alertView:clickedButtonAtIndex:, reset this reference to nil. Before displaying new errors, check if one is already visible.
Even better, don't display modal error messages from background processes. Just walking around, you'll occasionally lose reception, and it's tedious to have to dismiss an error when that happens. If your app has a configuration or help screen, include a space there for the most recent error message from the Location Manager (or Game Center, or iCloud, or anything else that loses connectivity occasionally.)
i want to add a alter if the user is not connected to the internet and clicks on a webview link.
-(void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error" message:#"Can't connect. Please check your internet Connection" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
[alert release];
}
Problem is here:
Void (-) gives error:(!)Invalid argument type 'void' to unary expression
Very possibly the problem does not lie with the -(void)webView:didFailLoadWithError method itself; rather, it seems you are using it in an incorrect way, i.e.. within an expression that requires a unary operator (e.g., negation, increment, etc.).
In other words, it seems you are trying to use the method's return value somewhere, but there is no return value from that method.
Check the code where you call -(void)webView:didFailLoadWithError...
This is very simple you dont have to code in any delegate method for check weather the user is connected to internet,for example the there is a login page for you and the user logs in but network is not connectd ,so we have to give an alert to user that the network is not connectd right?just simply add the
if(responce == nil)ie,responce from the url
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error" message:#"Can't connect. Please check your internet Connection" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
[alert release];
} else you code
When you first try to access a user's ALAssetsLibrary, the OS will present them with a dialog asking for permission. If they do not allow this, a failureBlock will be called and will always be called in the future. Is there a way to force a prompt of this authorization request again?
I notice in the Maps app, that they inform the user to go to the Settings app to turn on location services with a button. However, there is no way that I know of to programmatically open the Settings app. Should I just display directions as to how to turn on the location services?
You can't open up the settings app in an Apple approved manner.
The best you can hope for is to trap the error and then display a UIAlertView or other view with instructions on how to do this. Take a look at the latest v. of the Dropbox app for an idea on how they instruct the user.
When you try to access the Library from your code, you can use the error handler to catch the error and display an alert specifying to the user what to do.
Example
failureBlock:^(NSError *error) {
// error handling
if (error.code == ALAssetsLibraryAccessGloballyDeniedError) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error!"
message:#"Error loading image... \nEnable Location Services in 'Settings -> Location Services'."
delegate:self cancelButtonTitle:#"OK"
otherButtonTitles:nil, nil];
[alert show];
} else if (error.code == ALAssetsLibraryAccessUserDeniedError) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error!"
message:[NSString stringWithFormat:#"Error loading image... \nEnable Location Services in 'Settings -> Location Services' for %#.", [[[NSBundle mainBundle] infoDictionary] objectForKey:#"CFBundleDisplayName"]]
delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil, nil];
[alert show];
} else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error!" message:#"Error loading image..." delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil, nil];
[alert show];
}
}