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@gwhelanLD gwhelanLD released this Aug 13, 2021


  • Fixed an issue where 304 NOT_MODIFIED responses to SDK polling mode requests would be considered error responses. This could cause the completion on a identify request to not complete, and gave erroneous connection information data and logging output.
  • Fixed a crash when attempting to cache flag data containing variation JSON values containing a JSON null value nested within a JSON array.
Assets 2

@gwhelanLD gwhelanLD released this Jun 18, 2021


  • Avoid crash when TimeInterval configuration options are set to sufficiently large values. This was caused when converting these values to an Int value of milliseconds. (Thanks, @delannoyk!)
  • Update Package.swift to use SwiftPM tools version 5.2. This prevents test dependencies from being included transitively. (Thanks, @escakot!)
  • Update Quick test dependency to 3.1.2 to avoid build warnings and adopt security fixes. (#243)
  • Use AnyObject over class in protocol inheritance to avoid compiler warnings. (#247)
  • Improve CI to test against multiple supported Xcode and Swift language versions.
  • Restored test suite compatibility with Xcode 11.4 and Swift 5.2.
Assets 2

@torchhound torchhound released this Apr 7, 2021


  • Internal throttling logic would sometimes delay new poll or stream connections even when there were no recent connections. This caused switching active user contexts using identify to sometimes delay retrieving the most recent flags and calling the completion.
Assets 2

@gwhelanLD gwhelanLD released this Feb 26, 2021


  • Added the alias method to LDClient. This can be used to associate two user objects for analytics purposes with an alias event.
  • Added the autoAliasingOptOut configuration option. This can be used to control the new automatic aliasing behavior of the identify method; by setting autoAliasingOptOut to true, identify will not automatically generate alias events.
  • Added the isInitialized property to LDClient. Unless the client has been set offline, this property's value is false until the client receives an initial set of flag values from the LaunchDarkly service. If the client is offline, the value will be true after initialization.


  • The identify method will now automatically generate an alias event when switching from an anonymous to a known user. This event associates the two users for analytics purposes as they most likely represent a single person.


  • Some users reported synchronization issues with the internal DiagnosticReporter implementation, which has been reworked to address these issues. Thanks to @provanandparanjape for one such report (#238).
Assets 2

@gwhelanLD gwhelanLD released this Feb 11, 2021


  • Updated to prevent a crash in dispatch_group_leave.cold.1 that would rarely occur as the SDK transitioned to an online state for a given configuration or user. This issue may have been exacerbated for a short period due to a temporary change in the behavior of the LaunchDarkly service streaming endpoint. Thanks to all the users who reported (#235).
  • Updated LDSwiftEventSource dependency to correct an issue where a streaming connection could sometimes reconnect after being set offline.
Assets 2

@torchhound torchhound released this Dec 16, 2020


  • Decoupled FlagStore from LDUser to fix a bug where multiple environments could overwrite each other's flag values.
Assets 2

@gwhelanLD gwhelanLD released this Nov 6, 2020


  • Adds to LDConfig the ability to dynamically configure the HTTP headers on requests through the headerDelegate property, which has the type RequestHeaderTransform.
Assets 2

@gwhelanLD gwhelanLD released this Oct 9, 2020



  • Corrected a bug preventing private custom attribute names being recorded in events when all custom attributes are set to be private by including "custom" in the LDUser.privateAttributes or LDConfig.privateUserAttributes properties.
  • Update Nimble to 9.0 and Quick to 3.0 to fix tests when run with Swift 5.3.
  • Fixes build warnings in Xcode 12.0.0.
Assets 2

@gwhelanLD gwhelanLD released this Aug 4, 2020


  • The ability to specify additional headers to be included on HTTP requests to LaunchDarkly services using LDConfig.additionalHeaders. This feature is to enable certain proxy configurations, and is not needed for normal use.
  • Support for building docs with jazzy. These docs will be available through GitHub Pages.


  • SDK causing nested bundles in archived product when including the SDK through Carthage. This caused rejections when submitted to the App Store. Thanks to @spr for reporting (#217).
  • SDK causing application to expect LDSwiftEventSource dynamic framework when built with SwiftPM, which does not include the dynamic framework in the resulting application. This causes the application to be rejected when submitted to the App Store. Thanks to @spr for reporting (#216).
Assets 2

@gwhelanLD gwhelanLD released this Jul 23, 2020

Note that this release contains the notes for the 5.0.0 release, which should not be used.

This major version has an accompanying Migration Guide. Please see the guide for more information on updating to this version of the SDK, as the following is just a summary of the changes.


  • Support for multiple LaunchDarkly projects or environments. Each set of feature flags associated with a mobile key is called an environment. This adds:
    • LDConfig.setSecondaryMobileKeys and LDConfig.getSecondaryMobileKeys which allows configuring a mapping of names to the SDK keys for each additional environment. LDConfig.mobileKey is still required, and represents the primary environment.
    • LDClient.get(environment: ) which allows retrieving an LDClient instance for a given environment after the SDK has been initialized.
    • Equivalent methods have been added to the Objective-C bindings for LDConfig and LDClient.
  • The SDK now periodically sends diagnostic data to LaunchDarkly, describing the version and configuration of the SDK, the operating system the SDK is running on, the device type (such as "iPad"), and performance statistics. No credentials, device IDs, or other identifiable values are included. This behavior can be disabled or configured with the new LDConfig properties diagnosticOptOut and diagnosticRecordingInterval.
  • The SDK can now be configured with LDConfig.wrapperName and LDConfig.wrapperVersion to send an additional header (X-LaunchDarkly-Wrapper) in requests to LaunchDarkly. This was added so that the usage of wrapper libraries (such as the React Native SDK) could be recorded independently.
  • Added the evaluationReasons field to the Objective-C bindings for LDConfig to allow configuring the SDK to request evaluation reasons when the application is written in Objective-C.
  • The SDK now supports using the Swift Package Manager to include the SDK as a dependency.
  • LDInvalidArgumentError that is thrown on incorrect API usage.
  • Added typeMismatch field to ObjcLD<T>ChangedFlag classes (bound to LD<T>ChangedFlag in Objective-C) that is true/YES when the flag value did not match the registered observer.

Changed (build)

  • Minimum deployment targets have been changed as follows:
    • iOS 8.0 -> 10.0
    • macOS 10.10 -> 10.12
    • tvOS 9.0 -> 10.0
    • watchOS 2.0 -> 3.0
  • The SDK has replaced the internal dependency on the Objective-C eventsource implementation DarklyEventSource with a pure Swift implementation LDSwiftEventSource. Build configurations that manually specify the DarklyEventSource dependency framework may require additional upgrade steps. See the Migration Guide for more information.
  • Internally, the SDK no longer includes its dependencies using CocoaPods and Carthage. This simplifies including the SDK as a subproject of your application for integrating the SDK without a package manager.

Changed (API)

  • The LDClient instance method start has been replaced with a static method LDClient.start for initializing all configured environments.
  • LDChangedFlag no longer includes the oldValueSource and newValueSource properties, as LDFlagValueSource was removed.
  • The following were renamed for consistency internally and with other SDKs:
    • LDClient.reportEvents() has been renamed to LDClient.flush().
    • LDClient.stop() has been renamed to LDClient.close().
    • LDClient.trackEvent(key: data: ) method have been renamed to LDClient.track(key: data: )
    • LDClient.allFlagValues has been renamed to LDClient.allFlags.
    • EvaluationDetail has been renamed to LDEvaluationDetail.
    • The ObjC<T>EvaluationDetail classes have been renamed to corresponding ObjcLD<T>EvaluationDetail. The names when exposed in Objective-C have been updated to replace the ObjC prefix with LD, e.g. ObjCStringEvaluationDetail to LDStringEvaluationDetail.
  • LDClient.track no longer throws JSONError and instead throws LDInvalidArgumentError.
  • The fallback parameter of all LDClient and ObjcLDClient variation methods has been renamed to defaultValue to help distinguish it from fallback values in rules specified in the LaunchDarkly dashboard.

Changed (behavioral)

  • The maximum backoff delay between failed streaming connections has been reduced from an hour to 30 seconds. This is to prevent being unable to receive new flag values for up to an hour if the SDK has reached its maximum backoff due to a period of network connectivity loss.
  • The backoff on streaming connections will not be reset after just a successful connection, rather waiting for a healthy connection for one minute after receiving flags. This is to reduce congestion in poor network conditions or if extreme load prevents the LaunchDarkly service from maintaining an active streaming connection.
  • When sending events to LaunchDarkly, the SDK will now retry the request after a one second delay if it fails.
  • When events fail to be sent to LaunchDarkly, the SDK will no longer retain the events. This prevents double recording events when the LaunchDarkly service received the event but the SDK failed to receive the acknowledgement.
  • The LDClient.identify, LDClient.flush, LDClient.setOnline, and LDClient.close instance methods now operate on all configured environments. Any completion arguments will complete when the operation has completed for all configured environments.


  • The LDClient.shared static property and its ObjcLDClient.sharedInstance wrapper property has been removed. After calling LDClient.start, the initialized instances can be retrieved with LDClient.get(environment: ).
  • The LDClient.config and its ObjcLDClient.config wrapper property has been removed, configuration of the SDK should be done with LDClient.start.
  • The LDClient.user and its ObjcLDClient.user wrapper property has been removed. The initial user should be configured with LDClient.start, and updates to the user should be performed with LDClient.identify.
  • LDFlagValueSource and ObjcLDFlagValueSource were removed in favor of using LDEvaluationDetail and ObjcLD<T>EvaluationDetail.
  • The Objective-C wrapper classes ObjcLD<T>VariationValue (bound in Objective-C to LD<T>VariationValue), which wrapped a flag value and its source, have been removed.
  • variationAndSource methods were removed from LDClient and its ObjcLDClient wrapper in favor of variationDetail methods.
  • LDUser.init?(object: ) and corresponding ObjcLDUser failable initializers were removed.
  • JSONError and JSONErrorDomain extensions on JSONSerialization were removed.
  • Removed isEqual extension to Array, this was only intended for internal SDK use.
  • Removed == and != extension to Optional<[String: Any]> (note that this was not declared as Equatable conformance). This extension was only intended for internal SDK use.
  • Removed LDFlagValue enum and the ObjcLDFlagValue wrapper which were exposed but not used in any public APIs.
  • Removed Sysctl struct (only available on macOS) which was only intended for internal SDK use.
Assets 2