feat(plugin): proxy plugin properties

Rename RequiresPlugin decorator to CordovaProperty and replace getter so
we can forward property access to the underlying plugin property.

src/plugins/apprate.ts

@@ -1,4 +1,6 @@
-import {Plugin, Cordova} from './plugin';
+import {Plugin, Cordova, CordovaProperty} from './plugin';
+
+declare var window;
 
 /**
  * The AppRate plugin makes it easy to prompt the user to rate your app, either now, later, or never.
@@ -43,8 +45,10 @@ export class AppRate {
    * customLocale {Object} null - custom locale object
    * @type {{}}
    */
-  @Cordova()
-  static preferences = {};
+  @CordovaProperty
+  static get preferences(){
+    return window.AppRate.preferences;
+  }
 
   /**
    * Prompts the user for rating

src/plugins/device.ts

@@ -1,4 +1,4 @@
-import {Plugin, RequiresPlugin} from './plugin';
+import {Plugin, CordovaProperty} from './plugin';
 
 declare var window: {
   device: Device
@@ -49,8 +49,8 @@ export class Device {
  *
  * @returns {Object} The device object.
  */
-  @RequiresPlugin
-  static getDevice() {
+  @CordovaProperty
+  static get device() {
     return window.device;
   }
 }

src/plugins/plugin.ts

@@ -170,20 +170,20 @@ export function Cordova(opts:any = {}) {
 /**
  * Before calling the original method, ensure Cordova and the plugin are installed.
  */
-export function RequiresPlugin(target: Function, key: string, descriptor: TypedPropertyDescriptor<any>) {
-  let originalMethod = descriptor.value;
+export function CordovaProperty(target: Function, key: string, descriptor: TypedPropertyDescriptor<any>) {
+  let originalMethod = descriptor.get;
 
-  descriptor.value = function(...args: any[]) {
+  descriptor.get = function(...args: any[]) {
     // console.log('Calling', this);
     if(!window.cordova) {
       cordovaWarn(this.name, null);
-      return;
+      return {};
     }
 
     let pluginInstance = getPlugin(this.pluginRef);
     if(!pluginInstance) {
       pluginWarn(this, key);
-      return;
+      return {};
     }
     return originalMethod.apply(this, args);
   }

src/plugins/statusbar.ts

@@ -1,4 +1,4 @@
-import {Plugin, Cordova, RequiresPlugin} from './plugin';
+import {Plugin, Cordova, CordovaProperty} from './plugin';
 
 declare var window;
 
@@ -102,8 +102,8 @@ export class StatusBar {
   /**
    * Whether the StatusBar is currently visible or not.
    */
-  @RequiresPlugin
-  static isVisible() {
+  @CordovaProperty
+  static get isVisible() {
     return window.StatusBar.isVisible;
   }
 }