If you have not set up the RUM iOS SDK yet, follow the in-app setup instructions or refer to the RUM iOS setup documentation.

Enrich user sessions

iOS RUM automatically tracks attributes such as user activity, screens, errors, and network requests. See the RUM Data Collection documentation to learn about the RUM events and default attributes. You can further enrich user session information and gain finer control over the attributes collected by tracking custom events.

Custom Views

In addition to tracking views automatically, you can also track specific distinct views such as viewControllers when they become visible and interactive. Stop tracking when the view is no longer visible using the following methods in RUMMonitor.shared():

• .startView(viewController:)
• .stopView(viewController:)

For example:

import DatadogRUM

// in your `UIViewController`:
let rum = RUMMonitor.shared()

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    rum.startView(viewController: self)
}

override func viewDidDisappear(_ animated: Bool) {
  super.viewDidDisappear(animated)
  rum.stopView(viewController: self)
}

@import DatadogObjc;
// in your `UIViewController`:

DDRUMMonitor *rum = [DDRUMMonitor shared];

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];

    [rum startViewWithViewController:self name:nil attributes:nil];
}

- (void)viewDidDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];

    [rum stopViewWithViewController:self attributes:nil];
}

For more details and available options, filter the relevant file on GitHub for the DDRUMMonitor class.

Add your own performance timing

In addition to RUM’s default attributes, you can measure where your application is spending its time by using the addTiming(name:) API. The timing measure is relative to the start of the current RUM view.

For example, you can time how long it takes for your hero image to appear:

func onHeroImageLoaded() {
    let rum = RUMMonitor.shared()
    rum.addTiming(name: "hero_image")
}

- (void)onHeroImageLoad {
    [[DDRUMMonitor shared] addTimingWithName:@"hero_image"];
}

Once you set the timing, it is accessible as @view.custom_timings.<timing_name>. For example, @view.custom_timings.hero_image.

To create visualizations in your dashboards, create a measure first.

Custom Actions

In addition to tracking actions automatically, you can track specific custom user actions (taps, clicks, and scrolls) with the addAction(type:name:) API.

To manually register instantaneous RUM actions such as .tap on RUMMonitor.shared(), use .addAction(type:name:). For continuous RUM actions such as .scroll, use .startAction(type:name:) or .stopAction(type:name:).

For example:

import DatadogRUM

// in your `UIViewController`:

let rum = RUMMonitor.shared()

@IBAction func didTapDownloadResourceButton(_ sender: UIButton) {
    rum.addAction(
        type: .tap,
        name: sender.currentTitle ?? "",
    )
}

- (IBAction)didTapDownloadResourceButton:(UIButton *)sender {
    NSString *name = sender.currentTitle ? sender.currentTitle : @"";
    [[DDRUMMonitor shared] addActionWithType:DDRUMActionTypeTap name:name attributes:@{}];
}

Note: When using .startAction(type:name:) and .stopAction(type:name:), the action type must be the same. This is necessary for the RUM iOS SDK to match an action start with its completion.

Find more details and available options in the DDRUMMonitor class.

Custom Resources

In addition to tracking resources automatically, you can also track specific custom resources such as network requests or third-party provider APIs. Use the following methods on RUMMonitor.shared() to manually collect RUM resources:

• .startResource(resourceKey:request:)
• .stopResource(resourceKey:response:)
• .stopResourceWithError(resourceKey:error:)
• .stopResourceWithError(resourceKey:message:)

For example:

import DatadogRUM

// in your network client:

let rum = RUMMonitor.shared()

rum.startResource(
    resourceKey: "resource-key",
    request: request
)

rum.stopResource(
    resourceKey: "resource-key",
    response: response
)

// in your network client:

[[DDRUMMonitor shared] startResourceWithResourceKey:@"resource-key"
                                            request:request
                                         attributes:@{}];

[[DDRUMMonitor shared] stopResourceWithResourceKey:@"resource-key"
                                          response:response
                                        attributes:@{}];

Note: The String used for resourceKey in both calls must be unique for the resource you are calling. This is necessary for the RUM iOS SDK to match a resource’s start with its completion.

Find more details and available options in the DDRUMMonitor class.

Custom Errors

To track specific errors, notify RUMMonitor when an error occurs with the message, source, exception, and additional attributes. Refer to the Error Attributes documentation.

let rum = RUMMonitor.shared()
rum.addError(message: "error message.")

[[DDRUMMonitor shared] addErrorWithMessage:@"error message." stack:nil source:DDRUMErrorSourceCustom attributes:@{}];

For more details and available options, refer to the code documentation comments in the DDRUMMonitor class.

Track custom global attributes

In addition to the default RUM attributes captured by the RUM iOS SDK automatically, you can choose to add additional contextual information (such as custom attributes) to your RUM events to enrich your observability within Datadog.

Custom attributes allow you to filter and group information about observed user behavior (such as the cart value, merchant tier, or ad campaign) with code-level information (such as backend services, session timeline, error logs, and network health).

Set a custom global attribute

To set a custom global attribute, use RUMMonitor.shared().addAttribute(forKey:value:).

• To add an attribute, use RUMMonitor.shared().addAttribute(forKey: "some key", value: "some value").
• To update the value, use RUMMonitor.shared().addAttribute(forKey: "some key", value: "some other value").
• To remove the key, use RUMMonitor.shared().removeAttribute(forKey: "some key").

Track user sessions

Adding user information to your RUM sessions makes it easy to:

• Follow the journey of a given user
• Know which users are the most impacted by errors
• Monitor performance for your most important users

The following attributes are optional, you should provide at least one of them:

To identify user sessions, use the setUserInfo(id:name:email:) API.

For example:

Datadog.setUserInfo(id: "1234", name: "John Doe", email: "john@doe.com")

[DDDatadog setUserInfoWithId:@"1234" name:@"John Doe" email:@"john@doe.com" extraInfo:@{}];

Initialization Parameters

You can use the following properties in Datadog.Configuration when creating the Datadog configuration to initialize the library:

site

Sets the Datadog server endpoint that data is sent to.

batchSize

Sets the preferred size of batched data uploaded to Datadog. This value impacts the size and number of requests performed by the RUM iOS SDK (small batches mean more requests, but each request becomes smaller in size). Available values include: .small, .medium, and .large.

uploadFrequency

Sets the preferred frequency of uploading data to Datadog. Available values include: .frequent, .average, and .rare.

RUM configuration

You can use the following properties in RUM.Configuration when enabling RUM:

sessionSampleRate

Sets the sampling rate for RUM sessions. The sessionSampleRate value must be between 0.0 and 100.0. A value of 0.0 means no sessions are sent, 100.0 means all sessions are sent to Datadog. If not configured, the default value of 100.0 is used.

uiKitViewsPredicate

Enables tracking UIViewControllers as RUM views. You can use default implementation of predicate by setting the DefaultUIKitRUMViewsPredicate or implement your own UIKitRUMViewsPredicate customized for your app.

uiKitActionsPredicate

Enables tracking user interactions (taps) as RUM actions. You can use the default implementation of predicate by setting the DefaultUIKitRUMActionsPredicate or implement your own UIKitRUMActionsPredicate customized for your app.

urlSessionTracking

Enables tracking URLSession tasks (network requests) as RUM resources. The firstPartyHostsTracing parameter defines hosts that are categorized as first-party resources (if RUM is enabled) and have tracing information injected (if tracing feature is enabled). The resourceAttributesProvider parameter defines a closure to provide custom attributes for intercepted resources that is called for each resource collected by the RUM iOS SDK. This closure is called with task information and may return custom resource attributes or nil if no attributes should be attached.

viewEventMapper

Sets the data scrubbing callback for views. This can be used to modify view events before they are sent to Datadog. For more information, see Modify or drop RUM events.

resourceEventMapper

Sets the data scrubbing callback for resources. This can be used to modify or drop resource events before they are sent to Datadog. For more information, see Modify or drop RUM events.

actionEventMapper

Sets the data scrubbing callback for actions. This can be used to modify or drop action events before they are sent to Datadog. For more information, see Modify or drop RUM events.

errorEventMapper

Sets the data scrubbing callback for errors. This can be used to modify or drop error events before they are sent to Datadog. For more information, see Modify or drop RUM events.

longTaskEventMapper

Sets the data scrubbing callback for long tasks. This can be used to modify or drop long task events before they are sent to Datadog. For more information, see Modify or drop RUM events.

vitalsUpdateFrequency

Sets the preferred frequency of collecting mobile vitals. Available values include: .frequent (every 100ms), .average (every 500ms), .rare (every 1s), and .never (disable vitals monitoring).

Automatically track views

To automatically track views (UIViewControllers), use the uiKitViewsPredicate option when enabling RUM. By default, views are named with the view controller’s class name. To customize it, provide your own implementation of the predicate which conforms to UIKitRUMViewsPredicate protocol:

public protocol UIKitRUMViewsPredicate {
    func rumView(for viewController: UIViewController) -> RUMView?
}

@objc
public protocol DDUIKitRUMViewsPredicate: AnyObject {
    func rumView(for viewController: UIViewController) -> DDRUMView?
}

Inside the rumView(for:) implementation, your app should decide if a given UIViewController instance should start the RUM view (return value) or not (return nil). The returned RUMView value must specify the name and may provide additional attributes for the created RUM view.

For instance, you can configure the predicate to use explicit type check for each view controller in your app:

class YourCustomPredicate: UIKitRUMViewsPredicate {

    func rumView(for viewController: UIViewController) -> RUMView? {
        switch viewController {
        case is HomeViewController:     return .init(name: "Home")
        case is DetailsViewController:  return .init(name: "Details")
        default:                        return nil
        }
    }
}

@interface YourCustomPredicate : NSObject<DDUIKitRUMViewsPredicate>

@end

@implementation YourCustomPredicate

- (DDRUMView * _Nullable)rumViewFor:(UIViewController * _Nonnull)viewController {
    if ([viewController isKindOfClass:[HomeViewController class]]) {
        return [[DDRUMView alloc] initWithName:@"Home" attributes:@{}];
    }

    if ([viewController isKindOfClass:[DetailsViewController class]]) {
        return [[DDRUMView alloc] initWithName:@"Details" attributes:@{}];
    }

    return nil;
}

@end

You can even come up with a more dynamic solution depending on your app’s architecture.

For example, if your view controllers use accessibilityLabel consistently, you can name views by the value of accessibility label:

class YourCustomPredicate: UIKitRUMViewsPredicate {

    func rumView(for viewController: UIViewController) -> RUMView? {
        guard let accessibilityLabel = viewController.accessibilityLabel else {
            return nil
        }

        return RUMView(name: accessibilityLabel)
    }
}

@interface YourCustomPredicate : NSObject<DDUIKitRUMViewsPredicate>

@end

@implementation YourCustomPredicate

- (DDRUMView * _Nullable)rumViewFor:(UIViewController * _Nonnull)viewController {
    if (viewController.accessibilityLabel) {
        return [[DDRUMView alloc] initWithName:viewController.accessibilityLabel attributes:@{}];
    }

    return nil;
}

@end

Note: The RUM iOS SDK calls rumView(for:) many times while your app is running. It is recommended to keep its implementation fast and single-threaded.

Automatically track user actions

To automatically track user tap actions, set the uiKitActionsPredicate option when enabling RUM.

Automatically track network requests

To automatically track resources (network requests) and get their timing information such as time to first byte or DNS resolution, use the urlSessionTracking option when enabling RUM and enable URLSessionInstrumentation:

URLSessionInstrumentation.enable(
    with: .init(
        delegateClass: SessionDelegate.self
    )
)

let session = URLSession(
    configuration: .default,
    delegate: SessionDelegate(),
    delegateQueue: nil
)

DDURLSessionInstrumentationConfiguration *config = [[DDURLSessionInstrumentationConfiguration alloc] initWithDelegateClass:[SessionDelegate class]];
[DDURLSessionInstrumentation enableWithConfiguration:config];

NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]
                                                      delegate:[[SessionDelegate alloc] init]
                                                 delegateQueue:nil];

Also, you can configure first party hosts using urlSessionTracking. This classifies resources that match the given domain as “first party” in RUM and propagates tracing information to your backend (if you have enabled Tracing). Network traces are sampled with an adjustable sampling rate. A sampling of 20% is applied by default.

For instance, you can configure example.com as the first party host and enable both RUM and Tracing features:

import DatadogRUM

RUM.enable(
  with: RUM.Configuration(
    applicationID: "<rum application id>",
    uiKitViewsPredicate: DefaultUIKitRUMViewsPredicate(),
    uiKitActionsPredicate: DefaultUIKitRUMActionsPredicate(),
    urlSessionTracking: RUM.Configuration.URLSessionTracking(
        firstPartyHostsTracing: .trace(hosts: ["example.com"], sampleRate: 20)
    )
  )
)

URLSessionInstrumentation.enable(
    with: .init(
        delegateClass: SessionDelegate.self
    )
)

let session = URLSession(
    configuration: .default,
    delegate: SessionDelegate(),
    delegateQueue: nil
)

@import DatadogObjc;

DDRUMConfiguration *configuration = [[DDRUMConfiguration alloc] initWithApplicationID:@"<rum application id>"];
DDRUMURLSessionTracking *urlSessionTracking = [DDRUMURLSessionTracking new];
[urlSessionTracking setFirstPartyHostsTracing:[DDRUMFirstPartyHostsTracing alloc] initWithHosts:@[@"example.com"] sampleRate:20];
[configuration setURLSessionTracking:urlSessionTracking];

[DDRUM enableWith:configuration];

To add custom attributes to resources, use the URLSessionTracking.resourceAttributesProvider option when enabling the RUM. By setting attributes provider closure, you can return additional attributes to be attached to tracked resource.

For instance, you may want to add HTTP request and response headers to the RUM resource:

RUM.enable(
  with: RUM.Configuration(
    ...
    urlSessionTracking: RUM.Configuration.URLSessionTracking(
        resourceAttributesProvider: { request, response, data, error in
            return [
                "request.headers" : redactedHeaders(from: request),
                "response.headers" : redactedHeaders(from: response)
            ]
        }
    )
  )
)

If you don’t want to track requests, you can disable URLSessionInstrumentation for the delegate type:

```swift
URLSessionInstrumentation.disable(delegateClass: SessionDelegate.self)

[DDURLSessionInstrumentation disableWithDelegateClass:[SessionDelegate class]];

Automatically track errors

All “error” and “critical” logs sent with Logger are automatically reported as RUM errors and linked to the current RUM view:

import DatadogLogs

let logger = Logger.create()

logger.error("message")
logger.critical("message")

@import DatadogObjc;

DDLogger *logger = [DDLogger create];
[logger error:@"message"];
[logger critical:@"message"];

Similarly, all finished spans marked as error are reported as RUM errors:

import DatadogTrace

let span = Tracer.shared().startSpan(operationName: "operation")
// ... capture the `error`
span.setError(error)
span.finish()

// ... capture the `error`
id<OTSpan> span = [[DDTracer shared] startSpan:@"operation"];
[span setError:error];
[span finish];

Modify or drop RUM events

To modify attributes of a RUM event before it is sent to Datadog or to drop an event entirely, use the Event Mappers API when configuring the RUM iOS SDK:

let configuration = RUM.Configuration(
    applicationID: "<rum application id>",
    viewEventMapper: { viewEvent in
        return viewEvent
    }
    resourceEventMapper: { resourceEvent in
        return resourceEvent
    }
    actionEventMapper: { actionEvent in
        return actionEvent
    }
    errorEventMapper: { errorEvent in
        return errorEvent
    }
    longTaskEventMapper: { longTaskEvent in
        return longTaskEvent
    }
)

DDRUMConfiguration *configuration = [[DDRUMConfiguration alloc] initWithApplicationID:@"<rum application id>"];

[configuration setViewEventMapper:^DDRUMViewEvent * _Nonnull(DDRUMViewEvent * _Nonnull viewEvent) {
    return viewEvent;
}];

[configuration setErrorEventMapper:^DDRUMErrorEvent * _Nullable(DDRUMErrorEvent * _Nonnull errorEvent) {
    return errorEvent;
}];

[configuration setResourceEventMapper:^DDRUMResourceEvent * _Nullable(DDRUMResourceEvent * _Nonnull resourceEvent) {
    return resourceEvent;
}];

[configuration setActionEventMapper:^DDRUMActionEvent * _Nullable(DDRUMActionEvent * _Nonnull actionEvent) {
    return actionEvent;
}];

[configuration setLongTaskEventMapper:^DDRUMLongTaskEvent * _Nullable(DDRUMLongTaskEvent * _Nonnull longTaskEvent) {
    return longTaskEvent;
}];

Each mapper is a Swift closure with a signature of (T) -> T?, where T is a concrete RUM event type. This allows changing portions of the event before it is sent.

For example, to redact sensitive information in a RUM Resource’s url, implement a custom redacted(_:) -> String function and use it in resourceEventMapper:

let configuration = RUM.Configuration(
    applicationID: "<rum application id>",
    resourceEventMapper: { resourceEvent in
        var resourceEvent = resourceEvent
        resourceEvent.resource.url = redacted(resourceEvent.resource.url)
        return resourceEvent
    }
)

DDRUMConfiguration *configuration = [[DDRUMConfiguration alloc] initWithApplicationID:@"<rum application id>"];

[configuration setResourceEventMapper:^DDRUMResourceEvent * _Nullable(DDRUMResourceEvent * _Nonnull resourceEvent) {
    return resourceEvent;
}];

Returning nil from the error, resource, or action mapper drops the event entirely; the event is not sent to Datadog. The value returned from the view event mapper must not be nil (to drop views, customize your implementation of UIKitRUMViewsPredicate; read more in tracking views automatically).

Depending on the event’s type, only some specific properties can be modified:

Set tracking consent (GDPR compliance)

To be compliant with the GDPR regulation, the RUM iOS SDK requires the tracking consent value at initialization.

The trackingConsent setting can be one of the following values:

1. .pending: The RUM iOS SDK starts collecting and batching the data but does not send it to Datadog. The RUM iOS SDK waits for the new tracking consent value to decide what to do with the batched data.
2. .granted: The RUM iOS SDK starts collecting the data and sends it to Datadog.
3. .notGranted: The RUM iOS SDK does not collect any data. No logs, traces, or RUM events are sent to Datadog.

To change the tracking consent value after the RUM iOS SDK is initialized, use the Datadog.set(trackingConsent:) API call. The RUM iOS SDK changes its behavior according to the new value.

For example, if the current tracking consent is .pending:

• If you change the value to .granted, the RUM iOS SDK sends all current and future data to Datadog;
• If you change the value to .notGranted, the RUM iOS SDK wipes all current data and does not collect future data.

Sample RUM sessions

To control the data your application sends to Datadog RUM, you can specify a sampling rate for RUM sessions while initializing the RUM iOS SDK as a percentage between 0 and 100.

For example, to only keep 50% of sessions use:

let configuration = RUM.Configuration(
    applicationID: "<rum application id>",
    sessionSampleRate: 50
)

DDRUMConfiguration *configuration = [[DDRUMConfiguration alloc] initWithApplicationID:@"<rum application id>"];
configuration.sessionSampleRate = 50;

Sending data when device is offline

RUM ensures availability of data when your user device is offline. In cases of low-network areas, or when the device battery is too low, all the RUM events are first stored on the local device in batches. They are sent as soon as the network is available, and the battery is high enough to ensure the RUM iOS SDK does not impact the end user’s experience. If the network is not available while your application is in the foreground, or if an upload of data fails, the batch is kept until it can be sent successfully.

This means that even if users open your application while offline, no data is lost.

Note: The data on the disk is automatically discarded if it gets too old to ensure the RUM iOS SDK does not use too much disk space.

Further Reading

Additional helpful documentation, links, and articles:

Source code for dd-sdk-iosGITHUB RUM & Session ReplayDOCUMENTATION