dev.openfeature.sdk

Interface Hook<T>

Type Parameters:

T - The type of the flag being evaluated.

All Known Subinterfaces:

BooleanHook, DoubleHook, IntegerHook, StringHook

public interface Hook<T>

An extension point which can run around flag resolution. They are intended to be used as a way to add custom logic to the lifecycle of flag evaluation.

Method Summary

Modifier and Type	Method and Description
default void	after(HookContext<T> ctx, FlagEvaluationDetails<T> details, Map<String,Object> hints) Runs after a flag is resolved.
default Optional<EvaluationContext>	before(HookContext<T> ctx, Map<String,Object> hints) Runs before flag is resolved.
default void	error(HookContext<T> ctx, Exception error, Map<String,Object> hints) Run when evaluation encounters an error.
default void	finallyAfter(HookContext<T> ctx, Map<String,Object> hints) Run after flag evaluation, including any error processing.
default boolean	supportsFlagValueType(FlagValueType flagValueType)

Method Detail

before

default Optional<EvaluationContext> before(HookContext<T> ctx,
                                           Map<String,Object> hints)

Runs before flag is resolved.

Parameters:

ctx - Information about the particular flag evaluation

hints - An immutable mapping of data for users to communicate to the hooks.

Returns:

An optional EvaluationContext. If returned, it will be merged with the EvaluationContext instances from other hooks, the client and API.

after

default void after(HookContext<T> ctx,
                   FlagEvaluationDetails<T> details,
                   Map<String,Object> hints)

Runs after a flag is resolved.

Parameters:

ctx - Information about the particular flag evaluation

details - Information about how the flag was resolved, including any resolved values.

hints - An immutable mapping of data for users to communicate to the hooks.

error

default void error(HookContext<T> ctx,
                   Exception error,
                   Map<String,Object> hints)

Run when evaluation encounters an error. This will always run. Errors thrown will be swallowed.

Parameters:

ctx - Information about the particular flag evaluation

error - The exception that was thrown.

hints - An immutable mapping of data for users to communicate to the hooks.

finallyAfter

default void finallyAfter(HookContext<T> ctx,
                          Map<String,Object> hints)

Run after flag evaluation, including any error processing. This will always run. Errors will be swallowed.

Parameters:

ctx - Information about the particular flag evaluation

hints - An immutable mapping of data for users to communicate to the hooks.

supportsFlagValueType

default boolean supportsFlagValueType(FlagValueType flagValueType)