1. Fixed #284 by changing data type of MouseEvent.x, MouseEvent.y, MouseEvent.clientX, MouseEvent.clientY to float.

2. Added an exception handler to kwebConfig that allows to react to errors during the processing of websocket errors.
3. removed the throw exception part in debugErr in kweb_bootstrap as is intentionally breaks the client in case of an exception which is completely unnecessary if the error is not servere.

Author: felg2

src/main/kotlin/kweb/Kweb.kt

@@ -112,6 +112,8 @@ class Kweb private constructor(
             var plugins: List<KwebPlugin> = Collections.emptyList()
             var kwebConfig: KwebConfiguration = KwebDefaultConfiguration()
 
+
+
             @Deprecated("Please use the Ktor syntax for defining page handlers instead: $buildPageReplacementCode")
             var buildPage: (WebBrowser.() -> Unit)? = null
         }
@@ -298,6 +300,7 @@ class Kweb private constructor(
                     }
                 } catch (e: Exception) {
                     logger.error("Exception while receiving websocket message", e)
+                    kwebConfig.onWebsocketMessageHandlingFailure(e)
                 }
             }
         } finally {

src/main/kotlin/kweb/config/KwebConfiguration.kt

@@ -51,6 +51,18 @@ abstract class KwebConfiguration {
         logger.debug { "Configuration has been initialized successfully" }
     }
 
+
+    /**
+     * Override this function to handle uncaught exceptions of client callbacks.
+     * E.g. if the browser sends a websocket message back to the kweb instance
+     * and the message handler throws an uncaught exception, kweb will invoke
+     * this exception handler to expose the fact that a message could not be
+     * properly handled
+     */
+    open fun onWebsocketMessageHandlingFailure(ex: Exception){
+
+    }
+
     /**
      * Override the default robots.txt behavior, which is to return with a 404. Passed a Ktor [ApplicationCall]
      * which may be used to return whatever you wish.

src/main/kotlin/kweb/html/events/events.kt

@@ -44,8 +44,8 @@ data class MouseEvent(
     val altKey: Boolean,
     val button: Int,
     val buttons: Int,
-    val clientX: Int,
-    val clientY: Int,
+    val clientX: Float,
+    val clientY: Float,
     val ctrlKey: Boolean,
     val metaKey: Boolean,
     val movementX: Int? = null,
@@ -54,8 +54,8 @@ data class MouseEvent(
     val screenX: Int,
     val screenY: Int,
     val shiftKey: Boolean,
-    val x: Int = clientX,
-    val y: Int = clientY,
+    val x: Float = clientX,
+    val y: Float = clientY,
     /** @see kweb.Element.on **/
     val retrieved: JsonElement = JsonNull
 )

src/main/resources/kweb/kweb_bootstrap.js

@@ -88,7 +88,7 @@ function debugErr(debugToken, err, errMsg) {
         const message = {id: kwebClientId, error: err};
         sendMessage(JSON.stringify(message));
     } else {
-        throw err;
+        console.error(errMsg)
     }
 }