[FEATURE] Theming Parameters via CSS Variables

lib/engine.js

@@ -0,0 +1,8 @@
+let engineInfo;
+module.exports.getInfo = function() {
+	if (!engineInfo) {
+		const {name, version} = require("../package.json");
+		engineInfo = {name, version};
+	}
+	return engineInfo;
+};

lib/index.js

@@ -11,7 +11,7 @@ const fileUtilsFactory = require("./fileUtils");
 
 const Compiler = require("./Compiler");
 
-const themingParametersDataUri = require("./themingParameters/dataUri");
+const themingParameters = require("./themingParameters/index");
 
 // Workaround for a performance issue in the "css" parser module when used in combination
 // with the "colors" module that enhances the String prototype.
@@ -108,6 +108,8 @@ Builder.prototype.cacheTheme = function(result) {
  * @param {boolean} options.cssVariables whether or not to enable css variables output
  * @param {string} options.lessInput less string input
  * @param {string} options.lessInputPath less file input
+ * @param {themingParameters.STRATEGY} [options.themingParameters=DATA_URI]
+ *   Strategy of including theming parameters within library CSS
  * @returns {{css: string, cssRtl: string, variables: {}, imports: [], cssSkeleton: string, cssSkeletonRtl: string, cssVariables: string, cssVariablesSource: string }}
  */
 Builder.prototype.build = function(options) {
@@ -122,9 +124,16 @@ Builder.prototype.build = function(options) {
 		parser: {},
 		compiler: {},
 		library: {},
-		scope: {}
+		scope: {},
+		themingParameters: themingParameters.STRATEGY.DATA_URI
 	}, options);
 
+	if (!themingParameters.STRATEGY[options.themingParameters]) {
+		return Promise.reject(
+			new Error("Invalid themingParameters strategy provided! Valid values: CSS_VARIABLES, DATA_URI")
+		);
+	}
+
 	if (options.compiler.sourceMap) {
 		return Promise.reject(new Error("compiler.sourceMap option is not supported!"));
 	}
@@ -144,7 +153,7 @@ Builder.prototype.build = function(options) {
 	});
 
 	function addInlineParameters(result) {
-		return themingParametersDataUri.addInlineParameters({result, options});
+		return themingParameters.addInlineParameters({result, options});
 	}
 
 	function getScopeVariables(options) {

lib/themingParameters/cssVariables.js

@@ -0,0 +1,87 @@
+const engine = require("../engine");
+
+// match a CSS url
+// (taken from sap/ui/core/theming/Parameters.js)
+const rCssUrl = /url[\s]*\('?"?([^'")]*)'?"?\)/;
+
+module.exports = {
+	addInlineParameters({result, options}) {
+		// CSS Variables can only be added when the library name is known
+		if (typeof options.library !== "object" || typeof options.library.name !== "string") {
+			return;
+		}
+
+		const libraryNameDashed = options.library.name.replace(/\./g, "-");
+		const themeMetadata = this.getThemeMetadata({result, options});
+
+		const themeMetadataVariable = `
+:root {
+  --sapThemeMetaData-UI5-${libraryNameDashed}: ${JSON.stringify(themeMetadata)};
+}
+`;
+
+		const urlVariables = this.getUrlVariables({result});
+		const themingCssVariables = this.getThemingCssVariables({result});
+
+		const themingParameters = `
+/* Inline theming parameters (CSS Variables) */
+:root {
+  --sapUiTheme-${libraryNameDashed}: ${JSON.stringify(urlVariables)};
+${themingCssVariables}
+}
+`;
+
+		result.css += themeMetadataVariable + themingParameters;
+		if (options.rtl) {
+			result.cssRtl += themeMetadataVariable + themingParameters;
+		}
+	},
+	getThemeMetadata({result, options}) {
+		let scopes;
+		if (typeof result.variables.scopes === "object") {
+			scopes = Object.keys(result.variables.scopes);
+		} else {
+			scopes = [];
+		}
+
+		const libraryNameSlashed = options.library.name.replace(/\./g, "/");
+
+		// TODO: How to get theme name? .theming "sId"? parse from file path? new parameter?
+		const themeId = "<theme-name>";
+		// TODO: How to get base theme name(s)? Read from .theming?
+		const Extends = ["<base-theme>"];
+
+		const {version, name} = engine.getInfo();
+		return {
+			Path: `UI5.${libraryNameSlashed}.${themeId}.library`,
+			PathPattern: "/%frameworkId%/%libId%/themes/%themeId%/%fileId%.css",
+			Extends,
+			Scopes: scopes,
+			Engine: {
+				Version: version,
+				Name: name
+			},
+			Version: {
+				Build: "<TODO>", // TOOD: add new property options.library.version
+				Source: "<TODO>" // TOOD: add new property options.library.version
+			}
+		};
+	},
+	getUrlVariables({result}) {
+		const urlVariables = {};
+
+		// TODO: support scopes (default/scopes top-level properties, see runtime code)
+		Object.entries(result.variables).map(([name, value]) => {
+			if (rCssUrl.test(value)) {
+				urlVariables[name] = value;
+			}
+		});
+
+		return urlVariables;
+	},
+	getThemingCssVariables({result}) {
+		return Object.entries(result.variables).map(([name, value]) => {
+			return `  --${name}: ${value};`;
+		}).join("\n");
+	},
+};

lib/themingParameters/dataUri.js

@@ -2,7 +2,7 @@ module.exports = {
 	addInlineParameters: function({result, options}) {
 		// Inline parameters can only be added when the library name is known
 		if (typeof options.library !== "object" || typeof options.library.name !== "string") {
-			return result;
+			return;
 		}
 
 		const parameters = JSON.stringify(result.variables);
@@ -27,7 +27,5 @@ module.exports = {
 			// for the css variables build we just add it to the variables
 			result.cssVariables += parameterStyleRule;
 		}
-
-		return result;
 	}
 };

lib/themingParameters/index.js

@@ -0,0 +1,19 @@
+const themingParameters = {
+	addInlineParameters({result, options}) {
+		switch (options.themingParameters) {
+		case themingParameters.STRATEGY.DATA_URI:
+			require("./dataUri").addInlineParameters({result, options});
+			break;
+		case themingParameters.STRATEGY.CSS_VARIABLES:
+			require("./cssVariables").addInlineParameters({result, options});
+			break;
+		}
+		return result;
+	},
+	STRATEGY: {
+		DATA_URI: "DATA_URI",
+		CSS_VARIABLES: "CSS_VARIABLES"
+	}
+};
+
+module.exports = themingParameters;

package.json

@@ -92,6 +92,7 @@
 		"eslint-config-google": "^0.14.0",
 		"graceful-fs": "^4.2.8",
 		"mocha": "^8.4.0",
+		"mock-require": "^3.0.3",
 		"nyc": "^15.1.0",
 		"sinon": "^11.1.2"
 	}

test/lib/themingParameters/cssVariables.js

@@ -0,0 +1,75 @@
+/* eslint-env mocha */
+
+const assert = require("assert");
+const sinon = require("sinon");
+const mock = require("mock-require");
+
+describe("themingParameters/cssVariables", function() {
+	let themingParametersCssVariables;
+
+	before(() => {
+		mock("../../../lib/engine", {
+			getInfo: sinon.stub().returns({
+				name: "less-openui5",
+				version: "1.0.0-test"
+			})
+		});
+		themingParametersCssVariables = require("../../../lib/themingParameters/cssVariables");
+	});
+	after(() => {
+		mock.stopAll();
+	});
+
+	it("should not add theming parameters when library name is missing", function() {
+		const result = {};
+		const options = {};
+		const returnValue = themingParametersCssVariables.addInlineParameters({result, options});
+
+		assert.equal(returnValue, undefined, "nothing should be returned");
+		assert.deepEqual(result, {}, "result object should not be modified");
+	});
+
+	it("should add theming parameters to css", function() {
+		const result = {
+			css: "/* css */",
+			variables: {foo: "bar"}
+		};
+		const options = {
+			library: {
+				name: "sap.ui.test"
+			}
+		};
+		const expectedMetadata = {
+			Path: `UI5.sap/ui/test.<theme-name>.library`, // TODO: theme name placeholder
+			PathPattern: "/%frameworkId%/%libId%/themes/%themeId%/%fileId%.css",
+			Extends: ["<base-theme>"], // TODO: base theme placeholder
+			Scopes: [],
+			Engine: {
+				Version: "1.0.0-test",
+				Name: "less-openui5"
+			},
+			Version: {
+				Build: "<TODO>",
+				Source: "<TODO>"
+			}
+		};
+
+		const returnValue = themingParametersCssVariables.addInlineParameters({result, options});
+
+		assert.equal(returnValue, undefined, "nothing should be returned");
+		assert.deepEqual(result, {
+			variables: {foo: "bar"},
+			css: `/* css */
+:root {
+  --sapThemeMetaData-UI5-sap-ui-test: ${JSON.stringify(expectedMetadata)};
+}
+
+/* Inline theming parameters (CSS Variables) */
+:root {
+  --sapUiTheme-sap-ui-test: {};
+  --foo: bar;
+}
+`
+		}, "result.css should be enhanced");
+	});
+});

test/lib/themingParameters/dataUri.js

@@ -9,9 +9,9 @@ describe("themingParameters/dataUri", function() {
 	it("should not add theming parameters when library name is missing", function() {
 		const result = {};
 		const options = {};
-		const returnedResult = themingParametersDataUri.addInlineParameters({result, options});
+		const returnValue = themingParametersDataUri.addInlineParameters({result, options});
 
-		assert.equal(returnedResult, result, "result object reference should be returned");
+		assert.equal(returnValue, undefined, "nothing should be returned");
 		assert.deepEqual(result, {}, "result object should not be modified");
 	});
 
@@ -25,9 +25,9 @@ describe("themingParameters/dataUri", function() {
 				name: "sap.ui.test"
 			}
 		};
-		const returnedResult = themingParametersDataUri.addInlineParameters({result, options});
+		const returnValue = themingParametersDataUri.addInlineParameters({result, options});
 
-		assert.equal(returnedResult, result, "result object reference should be returned");
+		assert.equal(returnValue, undefined, "nothing should be returned");
 		assert.deepEqual(result, {
 			variables: {foo: "bar"},
 			css: `/* css */
@@ -50,9 +50,9 @@ describe("themingParameters/dataUri", function() {
 				name: "sap.ui.test"
 			}
 		};
-		const returnedResult = themingParametersDataUri.addInlineParameters({result, options});
+		const returnValue = themingParametersDataUri.addInlineParameters({result, options});
 
-		assert.equal(returnedResult, result, "result object reference should be returned");
+		assert.equal(returnValue, undefined, "nothing should be returned");
 		assert.deepEqual(result, {
 			variables: {
 				foo: "50%",
@@ -78,9 +78,9 @@ data:text/plain;utf-8,%7B%22foo%22%3A%2250%25%22%2C%22bar%22%3A%22%27%5C%22%27%2
 			},
 			rtl: true
 		};
-		const returnedResult = themingParametersDataUri.addInlineParameters({result, options});
+		const returnValue = themingParametersDataUri.addInlineParameters({result, options});
 
-		assert.equal(returnedResult, result, "result object reference should be returned");
+		assert.equal(returnValue, undefined, "nothing should be returned");
 		assert.deepEqual(result, {
 			variables: {foo: "bar"},
 			css: `/* css */
@@ -106,9 +106,9 @@ data:text/plain;utf-8,%7B%22foo%22%3A%2250%25%22%2C%22bar%22%3A%22%27%5C%22%27%2
 			},
 			cssVariables: true
 		};
-		const returnedResult = themingParametersDataUri.addInlineParameters({result, options});
+		const returnValue = themingParametersDataUri.addInlineParameters({result, options});
 
-		assert.equal(returnedResult, result, "result object reference should be returned");
+		assert.equal(returnValue, undefined, "nothing should be returned");
 		assert.deepEqual(result, {
 			variables: {foo: "bar"},
 			css: `/* css */
@@ -136,9 +136,9 @@ data:text/plain;utf-8,%7B%22foo%22%3A%2250%25%22%2C%22bar%22%3A%22%27%5C%22%27%2
 			rtl: true,
 			cssVariables: true
 		};
-		const returnedResult = themingParametersDataUri.addInlineParameters({result, options});
+		const returnValue = themingParametersDataUri.addInlineParameters({result, options});
 
-		assert.equal(returnedResult, result, "result object reference should be returned");
+		assert.equal(returnValue, undefined, "nothing should be returned");
 		assert.deepEqual(result, {
 			variables: {foo: "bar"},
 			css: `/* css */