Multiplatform Swift Support (#21)

.github/workflows/pull-request.yml

@@ -16,3 +16,14 @@ jobs:
               run: swift build -v
             - name: Run tests
               run: swift test -v
+
+    ubuntu-build:
+
+        runs-on: ubuntu-latest
+
+        steps:
+            - uses: actions/checkout@v2
+            - name: Build (Ubuntu)
+              run: swift build -v
+            - name: Run tests
+              run: swift test -v

FlagsmithClient/Classes/Internal/APIManager.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 /// Handles interaction with a **Flagsmith** api.
 class APIManager {

FlagsmithClient/Classes/Internal/FlagsmithAnalytics.swift

@@ -38,15 +38,33 @@ class FlagsmithAnalytics {
   }
 
   /// Invalidate and re-schedule timer for processing events
+  ///
+  /// On Apple (Darwin) platforms, this uses the Objective-C based
+  /// target/selector message sending API.
+  ///
+  /// Non-Darwin systems will use the corelibs Foundation block-based
+  /// api. Both platforms could use this approach, but the podspec
+  /// declares iOS 8.0 as a minimum target, and that api is only
+  /// available on 10+. (12.0 would be a good base in the future).
   private func setupTimer() {
     timer?.invalidate()
+    #if canImport(ObjectiveC)
     timer = Timer.scheduledTimer(
       timeInterval: TimeInterval(flushPeriod),
       target: self,
-      selector: #selector(postAnalytics(_:)),
+      selector: #selector(postAnalyticsWhenEnabled(_:)),
       userInfo: nil,
       repeats: true
     )
+    #else
+    timer = Timer.scheduledTimer(
+      withTimeInterval: TimeInterval(flushPeriod),
+      repeats: true,
+      block: { [weak self] _ in
+        self?.postAnalytics()
+      }
+    )
+    #endif
   }
 
   /// Reset events after successful processing.
@@ -61,15 +79,15 @@ class FlagsmithAnalytics {
   }
 
   /// Send analytics to the api when enabled.
-  @objc private func postAnalytics(_ timer: Timer) {
+  private func postAnalytics() {
     guard enableAnalytics else {
       return
     }
-
+    
     guard !events.isEmpty else {
       return
     }
-
+    
     apiManager.request(.postAnalytics(events: events)) { [weak self] (result: Result<Void, Error>) in
       switch result {
       case .failure:
@@ -79,4 +97,13 @@ class FlagsmithAnalytics {
       }
     }
   }
+
+  #if canImport(ObjectiveC)
+  /// Event triggered when timer fired.
+  ///
+  /// Exposed on Apple platforms to relay selector-based events
+  @objc private func postAnalyticsWhenEnabled(_ timer: Timer) {
+    postAnalytics()
+  }
+  #endif
 }

FlagsmithClient/Classes/Internal/Router.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 enum Router {
   private enum HTTPMethod: String {