fix(filter): check against null

source/components/datatable/datasource/rest.mjs

@@ -343,7 +343,7 @@ class Rest extends Datasource {
 	}
 
 	/**
-	 * Fetches the data from the rest api.
+	 * Writes the data to the rest api.
 	 * @return {Promise}
 	 */
 	write() {
@@ -426,12 +426,12 @@ function initFilter() {
 
 	this[filterObserverSymbol] = new Observer(() => {
 		const query = filterControl.getOption("query");
-		if (query === undefined) {
+		if (query === undefined || query === null) {
 			return;
 		}
 
 		this.setParameters({ query: query });
-		this.fetch()
+		this.read()
 			.then((response) => {
 				if (!(response instanceof Response)) {
 					return Promise.reject(new Error("response is not a Response object"));
@@ -536,7 +536,7 @@ function initAutoInit() {
 	}
 
 	queueMicrotask(() => {
-		this.fetch().catch(() => {});
+		this.read().catch(() => {});
 	});
 }
 
@@ -548,7 +548,7 @@ function initEventHandler() {
 		entries.forEach((entry) => {
 			if (entry.isIntersecting) {
 				if (entry.intersectionRatio > 0) {
-					this.fetch();
+					this.read();
 				}
 
 				// only load once