To reduce memory usage, when the web page unloads notify the server s…

…o it can drop the ClientState, relevent to #199 and #194

build.gradle

@@ -25,7 +25,7 @@ ext {
 }
 
 group 'com.github.kwebio'
-version '0.9.2'
+version '0.9.3'
 
 repositories {
     mavenCentral()

src/main/kotlin/kweb/Kweb.kt

@@ -316,6 +316,11 @@ class Kweb private constructor(
                                 message.historyStateChange != null -> {
 
                                 }
+                                message.terminateConnection -> {
+                                    logger.debug { "Notified of client termination for ${message.id}, invalidating cached ClientState" }
+                                    clientState.invalidate(message.id)
+                                }
+
                             }
                         }
                     }

src/main/kotlin/kweb/client/Client2ServerMessage.kt

@@ -10,6 +10,7 @@ data class Client2ServerMessage(
         val hello: Boolean? = true,
         val error: ErrorMessage? = null,
         val callback: C2SCallback? = null,
+        val terminateConnection : Boolean = false,
         val historyStateChange: C2SHistoryStateChange? = null
 ) {
 

src/main/resources/kweb/kweb_bootstrap.js

@@ -147,22 +147,26 @@ function sendMessage(msg) {
         console.debug("Sending WebSocket message", msg);
         socket.send(msg);
     } else {
-        /*console.debug(
-            "Queueing WebSocket message as connection isn't established",
-            msg
-        );*/
         preWSMsgQueue.push(msg);
     }
 }
 
 function callbackWs(callbackId, data) {
-    var msg = JSON.stringify({
+    const msg = JSON.stringify({
         id: kwebClientId,
         callback: {callbackId: callbackId, data: data}
     });
     sendMessage(msg);
 }
 
+window.addEventListener("beforeunload", function (event) {
+    const msg = JSON.stringify({
+        id: kwebClientId,
+        terminateConnection: true
+    });
+    sendMessage(msg);
+})
+
 /*
  * Utility functions
  */