Merge pull request #447 from sivaganeshrk/Structural/Facade_typescript

Added Structural/Facade Pattern for Typescript

Structural/Facade/README.md

@@ -7,3 +7,7 @@ of external code on the inner parts of a library, because the most part of the c
 
 The facade design pattern uses the interface methods to delegate functions to the more complex methods that are part of the system
 implementation, which remain hidden for outside code (normally the client code).
+
+## STRUCTURE
+
+<img src="../../media/facade.png" alt="Facade patterns">

Structural/Facade/typescript/facade.ts

@@ -0,0 +1,46 @@
+class Facade {
+  protected subsystem1: Subsystem1;
+
+  protected subsystem2: Subsystem2;
+
+  constructor(subsystem1?: Subsystem1, subsystem2?: Subsystem2) {
+    this.subsystem1 = subsystem1 || new Subsystem1();
+    this.subsystem2 = subsystem2 || new Subsystem2();
+  }
+
+  public operation(): string {
+    let result = "Facade initializes subsystems:\n";
+    result += this.subsystem1.operation1();
+    result += this.subsystem2.operation1();
+    result += "Facade orders subsystems to perform the action:\n";
+    result += this.subsystem1.operationN();
+    result += this.subsystem2.operationZ();
+
+    return result;
+  }
+}
+
+class Subsystem1 {
+  public operation1(): string {
+    return "Subsystem1: Ready!\n";
+  }
+
+  public operationN(): string {
+    return "Subsystem1: Go!\n";
+  }
+}
+
+class Subsystem2 {
+  public operation1(): string {
+    return "Subsystem2: Get ready!\n";
+  }
+
+  public operationZ(): string {
+    return "Subsystem2: Fire!";
+  }
+}
+
+const subsystem1 = new Subsystem1();
+const subsystem2 = new Subsystem2();
+const facade = new Facade(subsystem1, subsystem2);
+console.log(facade.operation());