1 files changed, 57 insertions, 0 deletions
diff --git a/frontend/src/dispatcher.js b/frontend/src/dispatcher.js
new file mode 100644
index 0000000..32f3f33
--- /dev/null
+++ b/frontend/src/dispatcher.js
@@ -0,0 +1,57 @@
+/*
+ * This file is part of caronte (https://github.com/eciavatta/caronte).
+ * Copyright (c) 2020 Emiliano Ciavatta.
+ *
+ * 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, version 3.
+ *
+ * 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/>.
+ */
+
+const _ = require("lodash");
+
+class Dispatcher {
+
+    constructor() {
+        this.listeners = [];
+    }
+
+    dispatch = (topic, payload) => {
+        this.listeners.filter((l) => l.topic === topic).forEach((l) => l.callback(payload));
+    };
+
+    register = (topic, callback) => {
+        if (typeof callback !== "function") {
+            throw new Error("dispatcher callback must be a function");
+        }
+        if (typeof topic === "string") {
+            this.listeners.push({topic, callback});
+        } else if (typeof topic === "object" && Array.isArray(topic)) {
+            topic.forEach((e) => {
+                if (typeof e !== "string") {
+                    throw new Error("all topics must be strings");
+                }
+            });
+
+            topic.forEach((e) => this.listeners.push({e, callback}));
+        } else {
+            throw new Error("topic must be a string or an array of strings");
+        }
+    };
+
+    unregister = (callback) => {
+        _.remove(this.listeners, (l) => l.callback === callback);
+    };
+
+}
+
+const dispatcher = new Dispatcher();
+
+export default dispatcher;