Status manager and footer status

app/assets/javascripts/app/services/statusManager.js

@@ -0,0 +1,67 @@
+class StatusManager {
+
+  constructor() {
+    this.statuses = [];
+    this.observers = [];
+  }
+
+  statusFromString(string) {
+    return {string: string};
+  }
+
+  replaceStatusWithString(status, string) {
+    this.removeStatus(status);
+    return this.addStatusFromString(string);
+  }
+
+  addStatusFromString(string) {
+    return this.addStatus(this.statusFromString(string));
+  }
+
+  addStatus(status) {
+    if(typeof status !== "object") {
+      console.error("Attempting to set non-object status", status);
+      return;
+    }
+
+    this.statuses.push(status);
+    this.notifyObservers();
+    return status;
+  }
+
+  removeStatus(status) {
+    _.pull(this.statuses, status);
+    this.notifyObservers();
+    return null;
+  }
+
+  getStatusString() {
+    let result = "";
+    this.statuses.forEach((status, index) => {
+      if(index > 0) {
+        result += "  ";
+      }
+      result += status.string;
+    })
+
+    return result;
+  }
+
+  notifyObservers() {
+    for(let observer of this.observers) {
+      observer(this.getStatusString());
+    }
+  }
+
+  addStatusObserver(callback) {
+    this.observers.push(callback);
+  }
+
+  removeStatusObserver(callback) {
+    _.pull(this.statuses, callback);
+  }
+
+
+}
+
+angular.module('app').service('statusManager', StatusManager);