feat(style-scope): Resolve css sheets from tns_modules

If the css sheet is not in the app directory, try to find it in the
tns_modules folder.

tests/app/ui/styling/style-tests.ts

@@ -12,6 +12,7 @@ import types = require("utils/types");
 import viewModule = require("ui/core/view");
 import styleModule = require("ui/styling/style");
 import dependencyObservableModule = require("ui/core/dependency-observable");
+import { resolveFileNameFromUrl } from "ui/styling/style-scope";
 
 export function test_css_dataURI_is_applied_to_backgroundImageSource() {
     var stack = new stackModule.StackLayout();
@@ -1382,9 +1383,9 @@ export function test_star_attr_selector_incorrect_syntax() {
 export function test_alone_attr_selector() {
     let testButton = new buttonModule.Button();
     testButton["testAttr"] = "flow";
-    
+
     let testCss = "[testAttr*='flower'] { background-color: #FF0000; } button { background-color: #00FF00; }";
-    
+
     let testFunc = function (views: Array<viewModule.View>) {
         // style from correct type css should be applied
         helper.assertViewBackgroundColor(testButton, "#00FF00");
@@ -1395,9 +1396,9 @@ export function test_alone_attr_selector() {
 export function test_UsingSameSelectors_ShouldApplyLatest() {
     let testButton = new buttonModule.Button();
     testButton.className = 'green';
-    
+
     let testCss = ".green { background-color: #FF0000; } .green { background-color: #00FF00; }";
-    
+
     let testFunc = function (views: Array<viewModule.View>) {
         // style from correct type css should be applied
         helper.assertViewBackgroundColor(testButton, "#00FF00");
@@ -1408,9 +1409,9 @@ export function test_UsingSameSelectors_ShouldApplyLatest() {
 export function test_UsingSameSelectorsWithSpecific_ShouldApplyLatest() {
     let testButton = new buttonModule.Button();
     testButton.className = 'red green';
-    
+
     let testCss = ".red { background-color: #FF0000; } Button.green { background-color: #00FF00; }";
-    
+
     let testFunc = function (views: Array<viewModule.View>) {
         // style from correct type css should be applied
         helper.assertViewBackgroundColor(testButton, "#00FF00");
@@ -1435,6 +1436,55 @@ export function test_CascadingClassNamesAppliesAfterPageLoad() {
     });
 }
 
+export function test_resolveFileNameFromUrl_local_file_tilda() {
+    const localFileExistsMock = (fileName: string ) => true;
+    let url = "~/theme/core.css";
+    let appDirectory = "app";
+    let expected = `${appDirectory}/theme/core.css`;
+    let result = resolveFileNameFromUrl(url, appDirectory, localFileExistsMock);
+
+    TKUnit.assertEqual(result, expected, "Should resolve local file with leading tilda (~/)");
+}
+
+export function test_resolveFileNameFromUrl_local_file_no_tilda() {
+    const localFileExistsMock = (fileName: string ) => true;
+    let url = "theme/core.css";
+    let appDirectory = "app";
+    let expected = `${appDirectory}/theme/core.css`;
+    let result = resolveFileNameFromUrl(url, appDirectory, localFileExistsMock);
+
+    TKUnit.assertEqual(result, expected, "Should resolve local file without leading tilda (no ~/)");
+}
+
+export function test_resolveFileNameFromUrl_external_file_tilda() {
+    const externalFileExistsMock = (fileName: string) => (fileName.indexOf("tns_modules") !== -1);
+    let url = "~/theme/core.css";
+    let appDirectory = "app";
+    let expected = `${appDirectory}/tns_modules/theme/core.css`;
+    let result = resolveFileNameFromUrl(url, appDirectory, externalFileExistsMock);
+
+    TKUnit.assertEqual(result, expected, "Should resolve file from tns_modules with leading tilda (~/)");
+}
+
+export function test_resolveFileNameFromUrl_external_file_no_tilda() {
+    const externalFileExistsMock = (fileName: string) => (fileName.indexOf("tns_modules") !== -1);
+    let url = "theme/core.css";
+    let appDirectory = "app";
+    let expected = `${appDirectory}/tns_modules/theme/core.css`;
+    let result = resolveFileNameFromUrl(url, appDirectory, externalFileExistsMock);
+
+    TKUnit.assertEqual(result, expected, "Should resolve file from tns_modules without leading tilda (no ~/)");
+}
+
+export function test_resolveFileNameFromUrl_unexisting_file() {
+    const fileDoesNotExistMock = (fileName: string) => false;
+    let url = "~/theme/core.css";
+    let appDirectory = "app";
+    let result = resolveFileNameFromUrl(url, appDirectory, fileDoesNotExistMock);
+
+    TKUnit.assertNull(result, "Shouldn't resolve unexisting file");
+}
+
 // <snippet module="ui/styling" title="styling">
-// For information and example how to use style properties please refer to special [**Styling**](../../../styling.md) topic. 
+// For information and example how to use style properties please refer to special [**Styling**](../../../styling.md) topic.
 // </snippet>

tns-core-modules/ui/styling/style-scope.d.ts

@@ -32,5 +32,6 @@ declare module "ui/styling/style-scope" {
         public getAnimations(ruleset: RuleSet): KeyframeAnimationInfo[];
     }
 
+    export function resolveFileNameFromUrl(url: string, appDirectory: string, fileExists: (string) => boolean): string;
     export function applyInlineSyle(view: view.View, style: string): void;
 }

tns-core-modules/ui/styling/style-scope.ts

@@ -149,13 +149,11 @@ export class StyleScope {
                     if (utils.isFileOrResourcePath(url)) {
                         ensureFS();
 
-                        let fileName = types.isString(url) ? url.trim() : "";
-                        if (fileName.indexOf("~/") === 0) {
-                            fileName = fs.path.join(fs.knownFolders.currentApp().path, fileName.replace("~/", ""));
-                        }
+                        let appDirectory = fs.knownFolders.currentApp().path;
+                        let fileName = resolveFileNameFromUrl(url, appDirectory, fs.File.exists);
 
-                        if (fs.File.exists(fileName)) {
-                            let file = fs.File.fromPath(fileName);
+                        if (fileName !== null) {
+                            let file: fileSystemModule.File = fs.File.fromPath(fileName);
                             let text = file.readTextSync();
                             if (text) {
                                 selectors = selectors.concat(StyleScope.createSelectorsFromCss(text, fileName, keyframes));
@@ -197,7 +195,7 @@ export class StyleScope {
     }
 
     public applySelectors(view: view.View): void {
-        this.ensureSelectors(); 
+        this.ensureSelectors();
 
         let state = this._selectors.query(view);
 
@@ -245,6 +243,26 @@ export class StyleScope {
     }
 }
 
+export function resolveFileNameFromUrl(url: string, appDirectory: string, fileExists: (string) => boolean): string {
+    let fileName: string = types.isString(url) ? url.trim() : "";
+
+    if (fileName.indexOf("~/") === 0) {
+        fileName = fileName.replace("~/", "");
+    }
+
+    let local = fs.path.join(appDirectory, fileName);
+    if (fileExists(local)) {
+        return local;
+    }
+
+    let external = fs.path.join(appDirectory, "tns_modules", fileName);
+    if (fileExists(external)) {
+        return external;
+    }
+
+    return null;
+}
+
 export function applyInlineSyle(view: view.View, style: string) {
     try {
         let syntaxTree = cssParser.parse("local { " + style + " }", undefined);