feat: change some things (#35)

Author: horvathandris

README.md

@@ -27,7 +27,7 @@ import gleam/dict
 import gleam/dynamic
 import gleam/io
 import gleam/option.{None}
-import openfeature/api as openfeature
+import openfeature
 import openfeature/client
 import openfeature/evaluation_context
 import openfeature/providers/in_memory
@@ -82,7 +82,7 @@ Further documentation can be found at <https://hexdocs.pm/openfeature>.
 Once you've added a provider as a dependency, it can be registered with OpenFeature like this:
 
 ```gleam
-import openfeature/api as openfeature
+import openfeature
 
 openfeature.set_provider(my_provider())
 ```
@@ -96,7 +96,7 @@ Sometimes, the value of a flag must consider some dynamic criteria about the app
 ```gleam
 import gleam/dynamic
 import gleam/option.{None}
-import openfeature/api as openfeature
+import openfeature
 import openfeature/client
 import openfeature/evaluation_context.{EvaluationContext}
 
@@ -141,7 +141,7 @@ TODO
 Clients can be assigned to a domain. A domain is a logical identifier which can be used to associate clients with a particular provider. If a domain has no associated provider, the default provider is used.
 
 ```gleam
-import openfeature/api as openfeature
+import openfeature
 
 // registering the default provider
 openfeature.set_provider(local_provider())
@@ -163,7 +163,7 @@ TODO
 The OpenFeature API provides a close function to perform a cleanup of all registered providers. This should only be called when your application is in the process of shutting down.
 
 ```gleam
-import openfeature/api as openfeature
+import openfeature
 
 openfeature.shutdown()
 ```

gleam.toml

@@ -1,5 +1,5 @@
 name = "openfeature"
-version = "0.5.0"
+version = "0.6.0"
 description = "The Gleam SDK for the OpenFeature specification."
 licences = ["Apache-2.0"]
 repository = { type = "github", user = "horvathandris", repo = "openfeature-gleam-sdk" }

src/openfeature/api.gleam src/openfeature.gleam

@@ -6,6 +6,7 @@ import gleam/result
 import openfeature/client.{type Client, Client, ClientMetadata}
 import openfeature/domain.{type Domain}
 import openfeature/evaluation_context.{type EvaluationContext, EvaluationContext}
+import openfeature/events.{type EventCallback}
 import openfeature/provider.{type FeatureProvider, type Metadata}
 import openfeature/providers/no_op
 import worm
@@ -21,12 +22,15 @@ type APIMessage {
   )
   GetProvider(reply_with: Subject(FeatureProvider), domain: Domain)
   SetContext(evaluation_context: EvaluationContext)
+  AddHandler(domain: Domain, callback: EventCallback)
+  RemoveHandler(domain: Domain, callback: EventCallback)
 }
 
 type API {
   API(
     provider_registry: Dict(Domain, FeatureProvider),
     global_context: EvaluationContext,
+    event_callbacks: Dict(Domain, List(EventCallback)),
   )
 }
 
@@ -35,7 +39,7 @@ fn get_api_subject() -> Subject(APIMessage) {
 }
 
 fn init_api() {
-  let initial_state = API(dict.new(), evaluation_context.empty())
+  let initial_state = API(dict.new(), evaluation_context.empty(), dict.new())
   let assert Ok(subject) =
     actor.start(initial_state, fn(message: APIMessage, state: API) {
       case message {
@@ -55,6 +59,14 @@ fn init_api() {
         SetContext(evaluation_context) ->
           set_context_internal(state, evaluation_context)
           |> actor.continue
+
+        AddHandler(domain, callback) ->
+          add_handler_internal(state, domain, callback)
+          |> actor.continue
+
+        RemoveHandler(domain, callback) ->
+          remove_handler_internal(state, domain, callback)
+          |> actor.continue
       }
     })
   subject
@@ -76,14 +88,14 @@ fn set_provider_internal(
   domain: Domain,
   provider: FeatureProvider,
 ) -> API {
-  provider.initialize(state.global_context)
-  |> actor.send(reply_with, _)
+  let init_result = provider.initialize(state.global_context)
+  actor.send(reply_with, init_result)
 
   let provider_registry =
     state.provider_registry
     |> dict.insert(domain, provider)
 
-  API(provider_registry, state.global_context)
+  API(provider_registry, state.global_context, state.event_callbacks)
 }
 
 fn get_provider() -> FeatureProvider {
@@ -147,7 +159,7 @@ fn set_context_internal(
   state: API,
   evaluation_context: EvaluationContext,
 ) -> API {
-  API(state.provider_registry, evaluation_context)
+  API(state.provider_registry, evaluation_context, state.event_callbacks)
 }
 
 pub fn shutdown() {
@@ -159,3 +171,31 @@ fn shutdown_internal(state: API) -> Nil {
   |> dict.values
   |> list.each(fn(provider) { provider.shutdown() })
 }
+
+fn add_handler_internal(
+  state: API,
+  domain: Domain,
+  callback: EventCallback,
+) -> API {
+  let domain_callbacks =
+    state.event_callbacks
+    |> dict.get(domain)
+    |> result.unwrap([])
+    |> list.prepend(callback)
+
+  state.event_callbacks
+  |> dict.insert(domain, domain_callbacks)
+  |> API(state.provider_registry, state.global_context, _)
+}
+
+fn remove_handler_internal(state: API, domain: Domain, callback: EventCallback) {
+  let domain_callbacks =
+    state.event_callbacks
+    |> dict.get(domain)
+    |> result.unwrap([])
+    |> list.drop_while(fn(x) { x == callback })
+
+  state.event_callbacks
+  |> dict.insert(domain, domain_callbacks)
+  |> API(state.provider_registry, state.global_context, _)
+}

src/openfeature/eventing.gleam src/openfeature/events.gleam

@@ -3,7 +3,7 @@ import gleam/dynamic.{type Dynamic}
 import gleam/option.{type Option}
 import openfeature/error.{type ErrorCode}
 
-type EventCallback =
+pub type EventCallback =
   fn(EventDetails) -> Nil
 
 type EventType {
@@ -23,8 +23,5 @@ type ProviderEventDetails {
 }
 
 type EventDetails {
-  EventDetails(
-    provider_name: String,
-    provider_event_details: ProviderEventDetails,
-  )
+  EventDetails(provider_name: String, event_details: ProviderEventDetails)
 }