> This page is for Applications Protection.

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.humansecurity.com/llms.txt.

# Callbacks from the SDK

#### v2.x

The SDK provides callbacks that will help you to handle events from it. There are 4 types of events:

1. The SDK is ready.
2. A request was blocked.
3. A challenge was solved by the user.
4. A challenge was cancelled by the user.

## The SDK is ready

This event means that the SDK was finished the start process successfully. When calling the `PerimeterX/start(appId:delegate:enableDoctorCheck:completion:)` function, you should provide a completion handler. Once the handler is called with `success == true` you know that the SDK is ready. In addition, you can register to this event in other places within your code, using the `PerimeterX/addInitializationFinishedCallback(forAppId:callback:)` function. Here is an example:

```swift
PerimeterX.addInitializationFinishedCallback(forAppId: nil) {
	print("PerimeterX is ready")
}
```

```objectivec
[PerimeterX addInitializationFinishedCallbackForAppId:nil callback:^{
	NSLog(@"PerimeterX is ready");
}];
```

You can call the `PerimeterX/addInitializationFinishedCallback(forAppId:callback:)` when the SDK is already ready. In this case, the callback will be called immediately.

## A request was blocked

This event occurred when a request was blocked by PerimeterX. Notice that this event is only for native URL requests. URL requests which are origin from web views won't trigger this event.

There are two ways to receive this event:

1. PerimeterX's delegate - The `delegate` object that conform to the `PerimeterXDelegate` protocol should implement the `PerimeterXDelegate/perimeterxDidRequestBlocked(forAppId:)` function.
2. Register to the event - you can register to this event in other places within your code, using the `PerimeterX/registerCallbackForRequestBlockedEvent(forAppId:callback:)` function. This function returns a Registration ID which can be used to unregister from this event with the `PerimeterX/unregisterCallbackForRequestBlockedEvent(forAppId:registrationId:)`. Here is an example:

```swift
let requestBlockedEventRegistrationId = PerimeterX.registerCallbackForRequestBlockedEvent {
	print("Request Blocked Event")
}
```

```objectivec
NSString *requestBlockedEventRegistrationId = [PerimeterX registerCallbackForRequestBlockedEventForAppId:nil callback:^{
	NSLog(@"Request Blocked Event");
}];
```

## A challenge was solved by the user

This event occurred when a challenge was solved by the user. Notice that this event is only for native URL requests. URL requests which are origin from web views won't trigger this event.

There are two ways to receive this event:

1. PerimeterX's delegate - The `delegate` object that conform to the `PerimeterXDelegate` protocol should implement the `PerimeterXDelegate/perimeterxDidChallengeSolved(forAppId:)` function.
2. Register to the event - you can register to this event in other places within your code, using the `PerimeterX/registerCallbackForChallengeSolvedEvent(forAppId:callback:)` function. This function returns a Registration ID which can be used to unregister from this event with the `PerimeterX/unregisterCallbackForChallengeSolvedEvent(forAppId:registrationId:)`. Here is an example:

```swift
let challengeSolvedEventRegistrationId = PerimeterX.registerCallbackForChallengeSolvedEvent {
	print("Challenge Solved Event")
}
```

```objectivec
NSString *challengeSolvedEventRegistrationId = [PerimeterX registerCallbackForChallengeSolvedEventForAppId callback:^{
	NSLog(@"Challenge Solved Event");
}];
```

## A challenge was cancelled by the user

This event occurred when a challenge was cancelled by the user. Notice that this event is only for native URL requests. URL requests which are origin from web views won't trigger this event.

There are two ways to receive this event:

1. PerimeterX's delegate - The `delegate` object that conform to the `PerimeterXDelegate` protocol should implement the `PerimeterXDelegate/perimeterxDidChallengeCancelled(forAppId:)` function.
2. Register to the event - you can register to this event in other places within your code, using the `PerimeterX/registerCallbackForChallengeCancelledEvent(forAppId:callback:)` function. This function returns a Registration ID which can be used to unregister from this event with the `PerimeterX/unregisterCallbackForChallengeCancelledEvent(forAppId:registrationId:)`. Here is an example:

```swift
let challengeCancelledEventRegistrationId = PerimeterX.registerCallbackForChallengeCancelledEvent {
	print("Challenge Cancelled Event")
}
```

```objectivec
NSString *challengeCancelledEventRegistrationId = [PerimeterX registerCallbackForChallengeCancelledEventForAppId callback:^{
	NSLog(@"Challenge Cancelled Event");
}];
```