updated websocket library with some checks and fixed createcharfromint

Author: ste93

Diff for: typescript/yarp-ws.ts

@@ -205,14 +205,10 @@ function createBottleFromString(data:string)
 // deprecated, need to switch to view
 function createcharfromint(num:number)
 {
-    var char1 = num %256
-    num = num /256
-    var char2 = num %256
-    num = num /256
-    var char3 = num %256
-    num = num /256
-    var char4 = num %256
-    return String.fromCharCode(char1,char2,char3,char4)
+    var arr = new ArrayBuffer(4); // an Int32 takes 4 bytes
+    var view = new DataView(arr);
+    view.setUint32(0, num, true); // byteOffset = 0; litteEndian = true
+    return convertArrayBufferToString(arr)
 }
 
 // closes a connection, since the connection must be closed from the server, it sends a message to the server to close the connection
@@ -240,9 +236,9 @@ function convertArrayBufferToString(buffer:ArrayBuffer){
 }
 
 // it prints the received object on the console
-function printBuffer(buffer:ArrayBuffer){
-
-    if (buffer.byteLength > 8){
+function printBuffer(buffer:ArrayBuffer)
+{
+    if (buffer.byteLength > 8) {
         console.log("handling bottle")
         console.log(handleBottle(buffer))
     } else {
@@ -292,8 +288,12 @@ function checkIfPortExistsAndConnect(buffer:ArrayBuffer){
     var url = "ws://" + ip + ":" + port + "?ws"
     console.log("the url to connect to is: " + url);
     var newWebsocket = connectToYarp(url);
-    newWebsocket.onmessage = logMessage
-    revertConnection(newWebsocket)
+    if (newWebsocket) {
+        newWebsocket.onmessage = logMessage
+        revertConnection(newWebsocket)
+    } else {
+        console.error("newWebsocket: " + url + "is undefined, check previous error")
+    }
     return newWebsocket
 }
 
@@ -305,7 +305,12 @@ function handleAddressResponse(data:any){
 
 // connects to yarp with the given url (TODO FIXME STE maybe it can be done only with ip and port?)
 function connectToYarp(url:string){
-    var websocket = new WebSocket(url);
+    var websocket
+    try {
+        websocket = new WebSocket(url);
+    } catch (error) {
+        console.error("websocket client: " + url + " - " + error);
+    }
     return websocket
 }
 
@@ -346,7 +351,6 @@ function setupNewConnectionToPort(websocket: WebSocket, portName: string, closeW
                 closeConnection(websocket)
             }
         }
-        console.log("sending message")
         websocket.onmessage = handler
         sendQueryMessage(websocket, portName)
     })
@@ -355,10 +359,18 @@ function setupNewConnectionToPort(websocket: WebSocket, portName: string, closeW
 
 function setupNewConnectionToPortWithAddress(rootip:string, rootport: number, portName: string){
     var websocket = connectToYarp("ws://" +rootip + ":" + rootport+ "?ws")
-    return setupNewConnectionToPort(websocket, portName, true)
+    if (websocket) {
+        return setupNewConnectionToPort(websocket, portName, true)
+    } else {
+        console.error("cannot connect to websocket " + portName)
+    }
 }
 
 function getPortAndIpWithAddress(rootip:string, rootport: number, portName: string){
     var websocket = connectToYarp("ws://" +rootip + ":" + rootport+ "?ws")
-    return getPortAndIp(websocket,portName, true)
+    if (websocket) {
+        return getPortAndIp(websocket,portName, true)
+    } else {
+        console.error("cannot connect to websocket " + portName)
+    }
 }