add API error handling

api/index.js

@@ -5,6 +5,7 @@ const WebSocket = require("ws");
 var last_status = {};
 var last_image;
 var received_picture = false;
+var received_error = false;
 
 app.use(express.static("public"));
 app.use(express.json());
@@ -32,7 +33,10 @@ ws.on("message", function message(message) {
   // console.log("RECEIVED: " + msg.data);
 });
 
-ws.on("error", console.error);
+ws.on("error", function error(err) {
+    console.error("error: " + err);
+    received_error = true;
+});
 
 // set the view engine to ejs
 app.set("view engine", "ejs");
@@ -74,8 +78,12 @@ app.post("/move", function (req, res) {
 app.get("/connect", function (req, res) {
     console.log("got connect request");
     ws = new WebSocket("ws://10.100.0.40:9001/");
-    while (api_connected == false) { }
+    while (api_connected == false && received_error == false) { }
+    if (api_connected) {
         res.status(200).json({ connected: true });
+    } else {
+        res.status(400).json({ connected: false });
+    }
     
 });
 

api/views/index.ejs

@@ -155,6 +155,14 @@
                     // console.log(status)
                     document.getElementById("connectedstatus").innerHTML = "Connected: " + status.connected;
                 }
+            } else {
+                console.log("error");
+                if (this.responseText.length > 0) {
+                    var status = JSON.parse(this.responseText);
+                    // console.log(status)
+                    document.getElementById("connectedstatus").innerHTML = "Connected: " + status.connected;
+                }
+                alert("Could not connect to API!");
             }
         };
         xhr.send();