feat(app): Add canGoBack to backButton event (#265)

Co-authored-by: jcesarmobile <[email protected]>
ionic-team · May 18, 2021 · 6d7861e · 6d7861e
1 parent 95920da
commit 6d7861e
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Showing 3 changed files with 22 additions and 3 deletions.
diff --git a/app/README.md b/app/README.md
@@ -321,6 +321,13 @@ Remove all native listeners for this plugin
 | **`error`**      | <code>{ message: string; }</code> | If the plugin call didn't succeed, it will contain the error message.                                                                             | 1.0.0 |
 
 
+#### BackButtonListenerEvent
+
+| Prop            | Type                 | Description                                                                                               | Since |
+| --------------- | -------------------- | --------------------------------------------------------------------------------------------------------- | ----- |
+| **`canGoBack`** | <code>boolean</code> | Indicates whether the browser can go back in history. False when the history stack is on the first entry. | 1.0.0 |
+
+
 ### Type Aliases
 
 
@@ -341,6 +348,6 @@ Remove all native listeners for this plugin
 
 #### BackButtonListener
 
-<code>(): void</code>
+<code>(event: <a href="#backbuttonlistenerevent">BackButtonListenerEvent</a>): void</code>
 
 </docgen-api>
diff --git a/app/android/src/main/java/com/capacitorjs/plugins/app/AppPlugin.java b/app/android/src/main/java/com/capacitorjs/plugins/app/AppPlugin.java
@@ -47,7 +47,9 @@ public void handleOnBackPressed() {
                         bridge.getWebView().goBack();
                     }
                 } else {
-                    notifyListeners(EVENT_BACK_BUTTON, new JSObject(), true);
+                    JSObject data = new JSObject();
+                    data.put("canGoBack", bridge.getWebView().canGoBack());
+                    notifyListeners(EVENT_BACK_BUTTON, data, true);
                     bridge.triggerJSEvent("backbutton", "document");
                 }
             }

diff --git a/app/src/definitions.ts b/app/src/definitions.ts
@@ -115,10 +115,20 @@ export interface RestoredListenerEvent {
   };
 }
 
+export interface BackButtonListenerEvent {
+  /**
+   * Indicates whether the browser can go back in history.
+   * False when the history stack is on the first entry.
+   *
+   * @since 1.0.0
+   */
+  canGoBack: boolean;
+}
+
 export type StateChangeListener = (state: AppState) => void;
 export type URLOpenListener = (event: URLOpenListenerEvent) => void;
 export type RestoredListener = (event: RestoredListenerEvent) => void;
-export type BackButtonListener = () => void;
+export type BackButtonListener = (event: BackButtonListenerEvent) => void;
 
 export interface AppPlugin {
   /**