Fix signal for asynchronous updates

Sources/Model/Data Flow/Signal.swift

@@ -8,12 +8,14 @@
 import Foundation
 
 /// A type that signalizes an action.
-public struct Signal: Sendable {
+public struct Signal: Model, Sendable {
 
     /// An action is signalized by toggling a boolean to `true` and back to `false`.
-    @State var boolean = false
+    var boolean = false
     /// A signal has a unique identifier.
     public let id: UUID = .init()
+    /// The model data.
+    public var model: ModelData?
 
     /// Whether the action has caused an update.
     public var update: Bool { boolean }
@@ -23,7 +25,11 @@ public struct Signal: Sendable {
 
     /// Activate a signal.
     public func signal() {
-        boolean = true
+        setModel { $0.boolean = true }
+    }
+
+    /// Destroy a signal.
+    mutating func destroySignal() {
         boolean = false
     }
 

Sources/View/StateWrapper.swift

@@ -55,6 +55,12 @@ struct StateWrapper: ConvenienceWidget {
             return
         }
         await content().updateStorage(storage, data: data, updateProperties: updateProperties, type: type)
+        for property in state {
+            if var value = property.value.content.value as? Signal, value.update {
+                value.destroySignal()
+                property.value.content.value = value
+            }
+        }
     }
 
     /// Get a view storage.