refactor(HMR): apply changes in application styles at runtime

tns-core-modules/application/application-common.ts

@@ -32,7 +32,14 @@ export function hasLaunched(): boolean {
 
 export { Observable };
 
-import { UnhandledErrorEventData, iOSApplication, AndroidApplication, CssChangedEventData, LoadAppCSSEventData } from ".";
+import {
+    AndroidApplication,
+    CssChangedEventData,
+    getRootView,
+    iOSApplication,
+    LoadAppCSSEventData,
+    UnhandledErrorEventData
+} from "./application";
 
 export { UnhandledErrorEventData, CssChangedEventData, LoadAppCSSEventData };
 
@@ -73,8 +80,19 @@ export function setApplication(instance: iOSApplication | AndroidApplication): v
 export function livesync(context?: HmrContext) {
     events.notify(<EventData>{ eventName: "livesync", object: app });
     const liveSyncCore = global.__onLiveSyncCore;
-    if (liveSyncCore) {
-        liveSyncCore(context);
+    let reapplyAppCss = false
+
+    if (context) {
+        const fullFileName = getCssFileName();
+        const fileName = fullFileName.substring(0, fullFileName.lastIndexOf(".") + 1);
+        const extensions = ["css", "scss"];
+        reapplyAppCss = extensions.some(ext => context.module === fileName.concat(ext));
+    }
+
+    if (reapplyAppCss) {
+        getRootView()._onCssStateChange();
+    } else if (liveSyncCore) {
+        liveSyncCore();
     }
 }
 

tns-core-modules/application/application.ios.ts

@@ -18,7 +18,6 @@ export * from "./application-common";
 import { createViewFromEntry } from "../ui/builder";
 import { ios as iosView, View } from "../ui/core/view";
 import { Frame, NavigationEntry } from "../ui/frame";
-import { loadCss } from "../ui/styling/style-scope";
 import * as utils from "../utils/utils";
 import { profile, level as profilingLevel, Level } from "../profiling";
 
@@ -162,7 +161,7 @@ class IOSApplication implements IOSApplicationDefinition {
             this.setWindowContent(args.root);
         } else {
             this._window = UIApplication.sharedApplication.delegate.window;
-        }
+        }   
     }
 
     @profile
@@ -226,21 +225,10 @@ class IOSApplication implements IOSApplicationDefinition {
         }
     }
 
-    public _onLivesync(context?: HmrContext): void {
-        let executeLivesync = true;
-        // HMR has context, livesync does not
-        if (context) {
-            if (context.module === getCssFileName()) {
-                loadCss(context.module);
-                this._rootView._onCssStateChange();
-                executeLivesync = false;
-            }
-        }
-        if (executeLivesync) {
-            // If view can't handle livesync set window controller.
-            if (!this._rootView._onLivesync()) {
-                this.setWindowContent();
-            }
+    public _onLivesync(): void {
+        // If view can't handle livesync set window controller.
+        if (!this._rootView._onLivesync()) {
+            this.setWindowContent();
         }
     }
 
@@ -276,8 +264,8 @@ exports.ios = iosApp;
 setApplication(iosApp);
 
 // attach on global, so it can be overwritten in NativeScript Angular
-(<any>global).__onLiveSyncCore = function __onLiveSyncCore(context?: HmrContext) {
-    iosApp._onLivesync(context);
+(<any>global).__onLiveSyncCore = function () {
+    iosApp._onLivesync();
 }
 
 let mainEntry: NavigationEntry;
@@ -391,4 +379,4 @@ global.__onLiveSync = function __onLiveSync(context?: HmrContext) {
     }
 
     livesync(context);
-}
+}