1 files changed, 62 insertions, 0 deletions
diff --git a/ext/fg/js/frontend-api-receiver.js b/ext/fg/js/frontend-api-receiver.js
new file mode 100644
index 00000000..f5d29f67
--- /dev/null
+++ b/ext/fg/js/frontend-api-receiver.js
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2019 Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+class FrontendApiReceiver {
+    constructor(source='', handlers={}) {
+        this.source = source;
+        this.handlers = handlers;
+
+        chrome.runtime.onConnect.addListener(this.onConnect.bind(this));
+    }
+
+    onConnect(port) {
+        if (port.name !== 'frontend-api-receiver') { return; }
+
+        port.onMessage.addListener(this.onMessage.bind(this, port));
+    }
+
+    onMessage(port, {id, action, params, target}) {
+        if (
+            target !== this.source ||
+            !this.handlers.hasOwnProperty(action)
+        ) {
+            return;
+        }
+
+        this.sendAck(port, id);
+
+        const handler = this.handlers[action];
+        handler(params).then(
+            result => {
+                this.sendResult(port, id, {result});
+            },
+            e => {
+                const error = typeof e.toString === 'function' ? e.toString() : e;
+                this.sendResult(port, id, {error});
+            });
+    }
+
+    sendAck(port, id) {
+        port.postMessage({type: 'ack', id});
+    }
+
+    sendResult(port, id, data) {
+        port.postMessage({type: 'result', id, data});
+    }
+}