What's the difference between `WKNavigationDelegate` `didFail` and `didFailProvisionalNavigation` - ios

iOS WKWebView's WKNavigationDelegate has two methods to handle a failed navigation:
webView(_:didFail:withError:): "Tells the delegate that an error occurred during navigation."
webView(_:didFailProvisionalNavigation:withError:): "Tells the delegate that an error occurred during the early navigation process."
The docs only tell us that the one type occurs earlier in the navigation process than the other. The error arguments are generic, so no help there. Brave and Firefox iOS only handle didFailProvisionalNavigation as far as I can tell from reading their source.
My questions are:
What's the difference exactly between the two types of errors?
Is there a list of errors that can occur for each?
When is it necessary to handle didFail seeing that browsers don't seem to handle that?

webView(_:didFailProvisionalNavigation:withError:)
This method handles errors that happen before the resource of the url can even be reached. These errors are mostly related to connectivity, the formatting of the url, or if using urls which are not supported.
The error codes delivered here are found in
https://developer.apple.com/documentation/cfnetwork/cfnetworkerrors
Typical examples are
kCFURLErrorTimedOut = -1001 // timed out
kCFURLErrorUnsupportedURL = -1002 // unsupported URL
kCFURLErrorCannotFindHost = -1003 // host can not be found
kCFURLErrorFileDoesNotExist = -1100 // file does not exist on the server
webView(_:didFail:withError:)
Here, errors are reported that happen while loading the resource. These are usually errors caused by the content of the page, like invalid code in the page itself that the parser can't handle.

Related

which include file has contain "wxEVT_WEBVIEW_LOADED" macro?

erlang 24.3.3 is used.
From the 24.3.3 document, the wx version is 2.1.3.
I have find 2.1.3's wx.hrl and it doesn't contain the wxEVT_WEBVIEW_LOADED and wxEVT_WEBVIEW_ERROR.
But in the doc, it says
Many of the methods in wxWebView are asynchronous, i.e. they return
immediately and perform their work in the background. This includes
functions such as loadURL/2 and reload/2. To receive notification of
the progress and completion of these functions you need to handle the
events that are provided. Specifically wxEVT_WEBVIEW_LOADED notifies
when the page or a sub-frame has finished loading and
wxEVT_WEBVIEW_ERROR notifies that an error has occurred.
My code is as follows:
Ad = wxWebView:new(Frame,?wxID_ANY,[{size,{1000,1000}}]),
lager:debug("_ad_1082:\t~p",[Ad]),
ok = wxWebView:loadURL(Ad,"http://www.baidu.com"),
wxFrame:connect(Ad, ?wxEVT_WEBVIEW_LOADED,[{callback,fun chair_launch_frame:update_webview/2},
{userData,{?CONST_FRAME_MAIN_AD_PRODUCER,Frame}}]),
wxFrame:connect(Ad, ?wxEVT_WEBVIEW_ERROR,[{callback,fun chair_launch_frame:update_webview/2},
{userData,{?CONST_FRAME_MAIN_AD_PRODUCER,Frame}}]),
The compiler give error messsage undefined macro 'wxEVT_WEBVIEW_LOADED'

Error handling in Swift AWSPolly

Every example of AWSPolly I can find says:
// Again, we ignore the errors in the example.
For example:
https://github.com/awslabs/aws-sdk-ios-samples/blob/master/Polly-Sample/Swift/PollySample/ViewController.swift
I cannot figure out how to handle the errors. What if internet service drops out and Polly can't be accessed. I'd like to use the internal voice. But I can't figure out.
I checked:
awsTask.isCanceled || awsTask.isFaulted
But neither of them are true if Internet service is not available.

webRTC on iOS: Can't send SDP answer, RTCPeerConnection.setRemoteDescription() failed

I'm using libjingle_peerconnection installed with cocoapods. When I receive SDP offer through signaling server from my caller, I'm trying to set this as a remote description, which triggers RTCSessionDescriptionDelegate peerConnection:didSetSessionDescriptionWithError:
with error:
Error Domain=RTCSDPError Code=-1 "(null)" UserInfo={error=Failed to set remote answer sdp: Called in wrong state: STATE_INIT}.
My code is:
- (void)transportChanell:(TransportChannel *)channel didReceivedSignalWithSessionDescription:(NSString *)sessionDescription withType:(NSString *)type {
RTCSessionDescription *remoteDesc = [[RTCSessionDescription alloc] initWithType:#"answer" sdp:sessionDescription];
[_peerConnection setRemoteDescriptionWithDelegate:self sessionDescription:remoteDesc];
}
I've investigated the problem quite a lot and found in webRTC source code the place, as I suppose, this error comes from BadRemoteSdp(type, BadStateErrMsg(state()), err_desc); and all possible states of WebRtcSession are:
STATE_INIT = 0,
STATE_SENTOFFER, // Sent offer, waiting for answer.
STATE_RECEIVEDOFFER, // Received an offer. Need to send answer.
STATE_SENTPRANSWER, // Sent provisional answer. Need to send answer.
STATE_RECEIVEDPRANSWER, // Received provisional answer, waiting for answer.
STATE_INPROGRESS, // Offer/answer exchange completed.
STATE_CLOSED, // Close() was called.
Any suggestions, please, what could I missed in caller or callee side?
The offer seems to be marked as an "answer" according to the error message. It fails because it then expects you to be in the STATE_SENTOFFER state.
If you have created an offer and sent it to the other party, you may have forgotten to call setLocalDescription first. If you did not send an offer from the failing client, the other party should be changed to send an offer instead of an answer.
In the event this helps anyone coming here from Google:
I ran into this problem myself, and it turned out I'd hastily copy-pasted some code from the offerer I'd written. So I was init'ing RTCSessionDescription with type RTCSdpTypeAnswer instead of RTCSdpTypeOffer.
Make sure when allocating your RTCSessionDescription that you're using the right type!

GameCenter: "The connection to service named com.apple.gamed was interrupted"

I get this error message
The connection to service named com.apple.gamed was interrupted, but
the message was sent over an additional proxy and therefore this proxy
has become invalid.
sometimes when calling
loadMatchesWithCompletionHandler:^(NSArray *matches, NSError *error)
What does it mean?
I'm on iOS 9.3.2
This is the worst possible answer, but it's my own experience with loading matches, I'm sorry to say: sometimes it works, sometimes it doesn't. I've received this error message before, and then had it go away after no code changes at all. Just try again.
Ok now I have more findings. Forget my comment to the other answer.
In my case I got the message when I did not use the #escaping keyword on a closure parameter of a function (using Swift 3 where closures are by default non-escaping). This function was called with a closure that did not refer to self (because it was not needed). However, that function called another function, forwarding the closure.
So in the end my closure ended up without a reference.
I recommend you keep a copy of your block that you use as an argument to loadMatchesWithCompletionHandler. This way the block is not released prematurely.
This also explains why the error occurs just sometimes and not always. It's typical for memory release issues.

How to fix "NSURLErrorDomain error code -999" in iOS

I've been trying to use Corona SDK's Facebook API to post the score on the game I'm developing on facebook. However, I'm having a problem with it. During the first time I try to post to facebook, I get this error after login and user authentication:
NSURLErrorDomain error code -999
Then, it won't post on facebook. What are possible causes of this error and how can I address it?
By the way, I am not using webview on my app. Just the widget api and a show_dialog listener in my Facebook class.
The error has been documented on the Mac Developer Library(iOS docs)
The concerned segment from the documentation will be:
URL Loading System Error Codes
These values are returned as the error code property of an NSError
object with the domain “NSURLErrorDomain”.
enum
{
NSURLErrorUnknown = -1,
NSURLErrorCancelled = -999,
NSURLErrorBadURL = -1000,
NSURLErrorTimedOut = -1001,
As you can see; -999 is caused by ErrorCancelled. This means: another request is made before the previous request is completed.
Just wanted to add here, when receiving a -999 "cancelled" the problem usually is one of two things:
You're executing the exact same request again.
You're maintaining a weak reference to your manager object that gets deallocated prematurely. (Create strong reference)
hjpotter92 is absolutely right, I just want to provide solution for my case. Hopefully it is useful for you as well. Here is my situation:
On log in page > press log in > pop up loading dialog > call log in service > dismiss dialog > push another screen > call another service --> cause error -999
To fix it, I put a delay between dismissing dialog and pushing new screen:
[indicatorAlert dismissWithClickedButtonIndex:0 animated:YES];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0.01 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
[self performSegueWithIdentifier:#"HomeSegue" sender:nil];
});
It is strange that this issue happens on iOS 7 only.
I have faced the same error with Alamofire and it was because the certificate pinning.
The certificate wasn't valid anymore, so I had to remove it and add the new one.
Hope it helps.
In addition to what Ramon wrote, there is a third possible reason when receiving a NSURLErrorDomain -999 cancelled:
You cancelled the task while it was executing either by calling .cancel() on the datatask object or because you used .invalidateAndCancel() on the session object. If you are creating a custom session with a delegate, you should call .invalidateAndCancel() or .finishTasksAndInvalidate() to resolve the strong reference between the session and its delegate, as mentioned in the Apple Developer Documentation:
The session object keeps a strong reference to the delegate until your app exits or explicitly invalidates the session. If you don’t invalidate the session, your app leaks memory until it exits.
If you are wondering about this logging behaviour, I found the following explanation in the Apple Developer forums:
By way of explanation, back in iOS 10 we introduced a new logging system-wide logging architecture (watch WWDC 2016 Session 721 Unified Logging and Activity Tracing for the details) and lots of subsystem, including CFNetwork, are in the process of moving over to that. Until that move is fully finished you’re going to encounter some weird edge cases like this one.
I didn't use Corona SDK's Facebook API but I encountered this problem when using Alamofire, the secondRequest always cancel in execution with the error -999, according to the posts I found on internet, the reason is that session property is deinit before completion of async work since it is out of the scope, I finally solved this problem by deinit the session property manually so the compiler won't deinit it at wrong position:
class SessionManager {
var session:SessionManager?
init() {
self.session = SessionManager(configuration:URLSessionConfiguration.ephemeral)
}
private func firstRequest() {
guard let session = self.session else {return}
session.request(request_url).responseData {response in
if let data=response.data {
self.secondRequest()
}
}
private func secondRequest() {
guard let session = self.session else {return}
session.request(request_url).responseData {response in
if let data=response.data {
self.secondRequest()
}
//session will no longer be needed, deinit it
self.session = nil
}
}
Our company's app has many -999 error in iOS. I have searched around, find the reason has two, like the network task has been dealloc or the certificate isn't valid. But I have checked our code, these two aren't possible. I am using Alamofire
which is using URLSession. Luckily, our company's android app's network is normal. So we check the difference. We found the http request from iOS is Http2.0, while android is Http1.1. So we force the backend http support version down to http1.1, then -999 error count descends!!!
I think there maybe some bug in Apple's URLSession. Check the link New NSURLSession for every DataTask overkill? for some detail thoughts
Please check If you call cancel() on URLSessionDataTask to fix
NSURLErrorDomain Code=-999 "cancelled"
I was getting this error in iOS specific version of Xamarin app. Not sure the underlying cause, but in my case was able to work around it by using post method instead of get for anything passing the server context in the request body -- which makes more sense anyway. Android / Windows / the service all handle the GET with content, but in iOS app will become partially unresponsive then spit out the 999 NSUrlErrorDomain stuff in the log. Hopefully, that helps someone else running into this. I assume the net code is getting stuck in a loop, but could not see the code in question.
For my Cordova project (or similar), turns out it was a plugin issue. Make sure you're not missing any plugins and make sure they're installed properly without issue.
Easiest way to verify this is simply to start fresh by recreating the Cordova project (cordova create <path>) along with the required platforms (cordova platform add <platform name>) and add each plugin with the verbose flag (--verbose) so that you can see if anything went wrong in the console log while the plugin is being downloaded, added to project and installed for each platform (cordova plugin add cordova-plugin-device --verbose)
Recap:
cordova create <path>
cordova platform add <platform name>
cordova plugin add cordova-plugin-device --verbose
For my case, I used an upload task post that did not need body contents:
// The `from: nil` induces error "cancelled" code -999
let task = session.uploadTask(with: urlRequest, from: nil, completionHandler: handler)
The fix is to use zero byte data instead of nil,
let task = session.uploadTask(with: urlRequest, from: Data(), completionHandler: handler)
The framework documentation doesn't specify why the from bodyData is an optional type, or what happens when it is nil.
We solved this problem by reloading the web view when it failed loading.
extension WebViewController: WKNavigationDelegate {
func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
webView.reload()
}
}

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