fix: optimize rest errors

source/components/datatable/status.mjs

@@ -84,7 +84,7 @@ class DatasourceStatus extends CustomElement {
      * @property {Object} datasource Datasource configuration
      * @property {string} datasource.selector The selector of the datasource
      * @property {Object} callbacks Callbacks
-	 * @property {Function} callbacks.onError Callback function for error handling
+     * @property {Function} callbacks.onError Callback function for error handling <code>function(message: string, event: Event): string</code>
      * @property {Object} timeouts Timeouts
      * @property {number} timeouts.message Timeout for the message
      * @property {Object} state State
@@ -132,6 +132,17 @@ class DatasourceStatus extends CustomElement {
         initEventHandler.call(this);
     }
 
+    /**
+     *
+     * @param message
+     * @param timeout
+     * @returns {DatasourceStatus}
+     */
+    setErrorMessage(message, timeout) {
+        this[errorElementSymbol].setErrorMessage(message, timeout);
+        return this;
+    }
+
     /**
      *
      * @return [CSSStyleSheet]
@@ -219,11 +230,11 @@ function initEventHandler() {
 
                 const callback = self.getOption("callbacks.onError", null);
                 if (callback) {
-					msg = callback(msg);
-				}
-
+                    callback.call(self, msg, event);
+                } else {
                     self[errorElementSymbol].setErrorMessage(msg, timeout);
                 }
+            }
         });
     }
 }

source/data/datasource/server/restapi.mjs

@@ -257,6 +257,7 @@ function fetchData(init, key, callback) {
 			if (callback && isFunction(callback)) {
 				callback(obj);
 			}
+
 			return response;
 		})
 		.catch((e) => {

source/data/datasource/server/restapi/data-fetch-error.mjs

@@ -32,8 +32,20 @@ class DataFetchError extends Error {
 	 */
 	constructor(message, response) {
 		super(message);
+
+		let body = null
+
+		if (response instanceof Response) {
+			body = response.text();
+		}
+
+		if(!(body instanceof Promise)) {
+			body = Promise.resolve(body);
+		}
+
 		this[internalSymbol] = {
 			response: response,
+			body : body
 		};
 	}
 
@@ -47,10 +59,17 @@ class DataFetchError extends Error {
 		);
 	}
 
+	/**
+	 * @return {string|Object}
+	 */
+	getBody() {
+		return this[internalSymbol]?.["body"];
+	}
+
 	/**
 	 * @return {Response}
 	 */
 	getResponse() {
-		return this[internalSymbol]["response"];
+		return this[internalSymbol]?.["response"];
 	}
 }

source/i18n/internal.mjs

@@ -28,7 +28,7 @@ function getInternalTranslations() {
 
 	let locale = "en";
 	try {
-		let locale = getLocaleOfDocument();
+		locale = getLocaleOfDocument();
 	} catch (error) {}
 
 	let messages = {};