Dynamic loader load style (#521)

* Remove unnecessary load of /fg/css/client.css

* Replace dynamicLoader.loadStyles with dynamicLoader.loadStyle

* Replace Popup._injectStylesheet with dynamicLoader.loadStyle

* Remove unused global

5 files changed, 70 insertions, 90 deletions

diff --git a/ext/bg/js/search-main.js b/ext/bg/js/search-main.js
index 6e092fbc..54fa549d 100644
--- a/ext/bg/js/search-main.js
+++ b/ext/bg/js/search-main.js
@@ -23,9 +23,6 @@
  */
 
 async function injectSearchFrontend() {
-    dynamicLoader.loadStyles([
-        '/fg/css/client.css'
-    ]);
     await dynamicLoader.loadScripts([
         '/mixed/js/text-scanner.js',
         '/fg/js/frontend-api-receiver.js',
diff --git a/ext/bg/settings-popup-preview.html b/ext/bg/settings-popup-preview.html
index 3d7f6455..2f0b841b 100644
--- a/ext/bg/settings-popup-preview.html
+++ b/ext/bg/settings-popup-preview.html
@@ -121,6 +121,7 @@
         <script src="/mixed/js/core.js"></script>
         <script src="/mixed/js/dom.js"></script>
         <script src="/mixed/js/api.js"></script>
+        <script src="/mixed/js/dynamic-loader.js"></script>
         <script src="/mixed/js/text-scanner.js"></script>
 
         <script src="/fg/js/document.js"></script>
diff --git a/ext/fg/js/popup.js b/ext/fg/js/popup.js
index 9e9debd8..b7d4b57e 100644
--- a/ext/fg/js/popup.js
+++ b/ext/fg/js/popup.js
@@ -17,8 +17,8 @@
 
 /* global
  * DOM
- * apiInjectStylesheet
  * apiOptionsGet
+ * dynamicLoader
  */
 
 class Popup {
@@ -180,12 +180,7 @@ class Popup {
     }
 
     async setCustomOuterCss(css, useWebExtensionApi) {
-        return await this._injectStylesheet(
-            'yomichan-popup-outer-user-stylesheet',
-            'code',
-            css,
-            useWebExtensionApi
-        );
+        return await dynamicLoader.loadStyle('yomichan-popup-outer-user-stylesheet', 'code', css, useWebExtensionApi);
     }
 
     setChildrenSupported(value) {
@@ -391,7 +386,7 @@ class Popup {
 
     async _injectStyles() {
         try {
-            await this._injectStylesheet('yomichan-popup-outer-stylesheet', 'file', '/fg/css/client.css', true);
+            await dynamicLoader.loadStyle('yomichan-popup-outer-stylesheet', 'file', '/fg/css/client.css', true);
         } catch (e) {
             // NOP
         }
@@ -717,71 +712,6 @@ class Popup {
         };
     }
 
-    async _injectStylesheet(id, type, value, useWebExtensionApi) {
-        const injectedStylesheets = Popup._injectedStylesheets;
-
-        if (yomichan.isExtensionUrl(window.location.href)) {
-            // Permissions error will occur if trying to use the WebExtension API to inject
-            // into an extension page.
-            useWebExtensionApi = false;
-        }
-
-        let styleNode = injectedStylesheets.get(id);
-        if (typeof styleNode !== 'undefined') {
-            if (styleNode === null) {
-                // Previously injected via WebExtension API
-                throw new Error(`Stylesheet with id ${id} has already been injected using the WebExtension API`);
-            }
-        } else {
-            styleNode = null;
-        }
-
-        if (useWebExtensionApi) {
-            // Inject via WebExtension API
-            if (styleNode !== null && styleNode.parentNode !== null) {
-                styleNode.parentNode.removeChild(styleNode);
-            }
-
-            await apiInjectStylesheet(type, value);
-
-            injectedStylesheets.set(id, null);
-            return null;
-        }
-
-        // Create node in document
-        const parentNode = document.head;
-        if (parentNode === null) {
-            throw new Error('No parent node');
-        }
-
-        // Create or reuse node
-        const isFile = (type === 'file');
-        const tagName = isFile ? 'link' : 'style';
-        if (styleNode === null || styleNode.nodeName.toLowerCase() !== tagName) {
-            if (styleNode !== null && styleNode.parentNode !== null) {
-                styleNode.parentNode.removeChild(styleNode);
-            }
-            styleNode = document.createElement(tagName);
-            styleNode.id = id;
-        }
-
-        // Update node style
-        if (isFile) {
-            styleNode.rel = value;
-        } else {
-            styleNode.textContent = value;
-        }
-
-        // Update parent
-        if (styleNode.parentNode !== parentNode) {
-            parentNode.appendChild(styleNode);
-        }
-
-        // Add to map
-        injectedStylesheets.set(id, styleNode);
-        return styleNode;
-    }
-
     static isFrameAboutBlank(frame) {
         try {
             const contentDocument = frame.contentDocument;
@@ -793,5 +723,3 @@ class Popup {
         }
     }
 }
-
-Popup._injectedStylesheets = new Map();
diff --git a/ext/manifest.json b/ext/manifest.json
index 865fe3f3..c87b9296 100644
--- a/ext/manifest.json
+++ b/ext/manifest.json
@@ -38,6 +38,7 @@
             "mixed/js/core.js",
             "mixed/js/dom.js",
             "mixed/js/api.js",
+            "mixed/js/dynamic-loader.js",
             "mixed/js/text-scanner.js",
             "fg/js/document.js",
             "fg/js/frontend-api-sender.js",
diff --git a/ext/mixed/js/dynamic-loader.js b/ext/mixed/js/dynamic-loader.js
index 51b6821b..ce946109 100644
--- a/ext/mixed/js/dynamic-loader.js
+++ b/ext/mixed/js/dynamic-loader.js
@@ -15,19 +15,72 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+/* global
+ * apiInjectStylesheet
+ */
+
 const dynamicLoader = (() => {
-    function loadStyles(urls) {
-        const parent = document.head;
-        for (const url of urls) {
-            const node = parent.querySelector(`link[href='${escapeCSSAttribute(url)}']`);
-            if (node !== null) { continue; }
-
-            const style = document.createElement('link');
-            style.rel = 'stylesheet';
-            style.type = 'text/css';
-            style.href = url;
-            parent.appendChild(style);
+    const injectedStylesheets = new Map();
+
+    async function loadStyle(id, type, value, useWebExtensionApi=false) {
+        if (useWebExtensionApi && yomichan.isExtensionUrl(window.location.href)) {
+            // Permissions error will occur if trying to use the WebExtension API to inject into an extension page
+            useWebExtensionApi = false;
+        }
+
+        let styleNode = injectedStylesheets.get(id);
+        if (typeof styleNode !== 'undefined') {
+            if (styleNode === null) {
+                // Previously injected via WebExtension API
+                throw new Error(`Stylesheet with id ${id} has already been injected using the WebExtension API`);
+            }
+        } else {
+            styleNode = null;
+        }
+
+        if (useWebExtensionApi) {
+            // Inject via WebExtension API
+            if (styleNode !== null && styleNode.parentNode !== null) {
+                styleNode.parentNode.removeChild(styleNode);
+            }
+
+            injectedStylesheets.set(id, null);
+            await apiInjectStylesheet(type, value);
+            return null;
         }
+
+        // Create node in document
+        const parentNode = document.head;
+        if (parentNode === null) {
+            throw new Error('No parent node');
+        }
+
+        // Create or reuse node
+        const isFile = (type === 'file');
+        const tagName = isFile ? 'link' : 'style';
+        if (styleNode === null || styleNode.nodeName.toLowerCase() !== tagName) {
+            if (styleNode !== null && styleNode.parentNode !== null) {
+                styleNode.parentNode.removeChild(styleNode);
+            }
+            styleNode = document.createElement(tagName);
+        }
+
+        // Update node style
+        if (isFile) {
+            styleNode.rel = 'stylesheet';
+            styleNode.href = value;
+        } else {
+            styleNode.textContent = value;
+        }
+
+        // Update parent
+        if (styleNode.parentNode !== parentNode) {
+            parentNode.appendChild(styleNode);
+        }
+
+        // Add to map
+        injectedStylesheets.set(id, styleNode);
+        return styleNode;
     }
 
     function loadScripts(urls) {
@@ -80,7 +133,7 @@ const dynamicLoader = (() => {
 
 
     return {
-        loadStyles,
+        loadStyle,
         loadScripts
     };
 })();