CallKit Reject Inbound Call (Objective-C) - ios

Question

I am working on a VOIP application (let's call it SampleApp) using CallKit and am struggling with an issue.
I can answer an inbound SampleApp call in a way that appears to work correctly using CallKit. However, when I reject a call, the call is instantiated anyway, which is incorrect behaviour.
To the extend of my understanding I need to get a boolean somehow depending on whether the call was accepted and rejected and then use this to decide whether the phone controller answers the incoming call.
PhoneViewController.m
- (void) presentIncomingCallAlertForCall:(SampleAppClientCall*)call
{
callIdentifier = [[NSUUID alloc] init];
// Use CallKit if iPhone
if(UI_USER_INTERFACE_IDIOM() != UIUserInterfaceIdiomPad)
{
[_pDelegate reportIncomingCall:callIdentifier
handle:call.remoteAddress
hasVideo:hasVideo
completionHandler: nil];
[self answerIncomingCall];
}
// Use Notification mechanism if iPad
else
{
// etc.
}
}
ProviderDelegate.m
-(void) reportIncomingCall: (NSUUID *) uuid
handle: (NSString *) handle
hasVideo: (BOOL) hasVideo
completionHandler:
(nullable void (^) (NSArray * _Nullable results, NSError * _Nonnull error))completionHandler
{
CXCallUpdate *update = [[CXCallUpdate alloc] init];
update.remoteHandle = [[CXHandle alloc] initWithType:CXHandleTypePhoneNumber
value:handle];
update.hasVideo = hasVideo;
[provider reportNewIncomingCallWithUUID:uuid
update:update
completion: ^(NSError *error)
{
// not sure what to put here?
}];
}
- (void) provider: (CXProvider *)provider
performAnswerCallAction : (CXAnswerCallAction *)action
{
NSDate *now = [[NSDate alloc] init];
[action fulfillWithDateConnected: now];
}
This is my first question, I've read the Stack Overflow guidelines but please tell me if I did anything wrong.

Answer 1

However, when I reject a call, the call is instantiated anyway, which
is incorrect behaviour.
It's unclear what you are trying to do in your code here. You always call [self answerIncomingCall]; (which we do not see the code to, but which I assume reports to your app logic and to your backend that the user has answered the call) right after [_pDelegate reportIncomingCall:...], so it seems like you are assuming that the user has decided to answer it, even before the user has done anything.
Rather, you should be telling your app logic and your backend that the user has answered the call, only in your -provider:performAnswerCallAction: method, and in your -provider:performEndCallAction:, tell your app logic and your backend that the user has declined the call (if it was a ringing incoming call).

Answer 2

Here is the solution based on the advice of #user102008 that resulted in what I wanted to achieve.
I moved the responsibility for answering the incoming call to the provider delegate instead of the phone view controller, which invokes the answer call or end call method depending on whether a call is accepted or rejected respectively in its provider methods.
PhoneViewController.m
- (void) presentIncomingCallAlertForCall:(SampleAppClientCall*)call {
callIdentifier = [[NSUUID alloc] init];
// Use CallKit if iPhone
if(UI_USER_INTERFACE_IDIOM() != UIUserInterfaceIdiomPad) {
[_pDelegate reportIncomingCall:callIdentifier
handle:call.remoteAddress
hasVideo:hasVideo
completionHandler: nil];
}
// Use Notification mechanism if iPad
else {
...
}
}
ProviderDelegate.h
-(void) reportIncomingCall: (NSUUID *) uuid
handle: (NSString *) handle
hasVideo: (BOOL) hasVideo
completionHandler: (nullable void (^) (NSArray * _Nullable results, NSError * _Nonnull error))
completionHandler {
CXCallUpdate *update = [[CXCallUpdate alloc] init];
update.remoteHandle = [[CXHandle alloc] initWithType:CXHandleTypePhoneNumber value:handle];
update.hasVideo = hasVideo;
[provider reportNewIncomingCallWithUUID:uuid
update:update
completion: ^(NSError *error) {
if (error) {
[self reportCallEnded:uuid reason:(NSInteger *)CXCallEndedReasonFailed];
}
}];
}
- (void) provider: (CXProvider *)provider performAnswerCallAction: (CXAnswerCallAction *)action {
[_phoneVC answerIncomingCall];
NSDate *now = [[NSDate alloc] init];
[action fulfillWithDateConnected: now];
}
- (void) provider: (CXProvider *)provider performEndCallAction: (CXEndCallAction *)action {
[_phoneVC rejectIncomingCall];
NSDate *now = [[NSDate alloc] init];
[action fulfillWithDateEnded: now];
}