hilla: document request options

articles/hilla/lit/guides/endpoints.adoc

@@ -417,6 +417,31 @@
 endif::[]
 
 
+== Request Options
+
+All regular Hilla requests support some options as the last parameter. They're listed in the sections here.
+
+
+=== Abort Signal
+
+You can pass an https://developer.mozilla.org/en-US/docs/Web/API/AbortController/signal[AbortSignal] object to the call to cancel a request. This is useful when you want to cancel a request, perhaps because you've decide you don't need it after all or because it's taking too long.
+
+[source,typescript]
+----
+include::{root}{root-fix}/frontend/demo/fusion/options/request-options.ts[tag=abort,indent=0]
+----
+
+
+=== Suppress Connection State
+
+By default, when a request takes too long, Hilla shows a progress bar to the user at the top of the page. You can suppress this by setting the `mute` option to `true`.
+
+[source,typescript]
+----
+include::{root}{root-fix}/frontend/demo/fusion/options/request-options.ts[tag=mute,indent=0]
+----
+
+
 == Code Completion in IDEs
 
 As you can see in the earlier [filename]`CounterEndpoint.ts` example, the Javadoc for the `@Endpoint` class is copied to the generated TypeScript file, and the type definitions are maintained. This helps code completion to work -- at least in Visual Studio Code and IntelliJ IDEA Ultimate Edition.

frontend/demo/fusion/options/request-options.ts

@@ -0,0 +1,23 @@
+import { SlowService } from 'Frontend/generated/endpoints';
+
+export function abortCall() {
+  // tag::abort[]
+  const controller = new AbortController();
+
+  SlowService.takesTime({ signal: controller.signal }).then((msg) => console.log(msg));
+
+  // The `AbortController` can be used to abort the request, for example after a timeout
+  // or an user action like a button click
+  const timeoutId = setTimeout(() => {
+    controller.abort();
+  }, 5000);
+  // end::abort[]
+
+  return () => clearTimeout(timeoutId);
+}
+
+export function muteCall() {
+  // tag::mute[]
+  SlowService.takesTime({ mute: true }).then((msg) => console.log(msg));
+  // end::mute[]
+}

src/main/java/com/vaadin/demo/fusion/options/SlowService.java

@@ -0,0 +1,23 @@
+package com.vaadin.demo.fusion.options;
+
+import org.jspecify.annotations.NonNull;
+
+import com.vaadin.flow.server.auth.AnonymousAllowed;
+import com.vaadin.hilla.BrowserCallable;
+
+@BrowserCallable
+@AnonymousAllowed
+public class SlowService {
+
+    @NonNull
+    public String takesTime() {
+        try {
+            Thread.sleep(10000); // Simulate a long process
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            return "Process was interrupted";
+        }
+        return "Process completed";
+    }
+
+}