feat(android): add clearHistory, clearCache and clearFormData (#450)

* add clearHistory, clearCache and clearFormData android webview api.

* remove pointless `async`

* add docs for new android webview methods

* Update Reference.md

* update commands types

* add more strict type for RNCWebViewUIManager `Commands` property

android/src/main/java/com/reactnativecommunity/webview/RNCWebViewManager.java

   public static final int COMMAND_INJECT_JAVASCRIPT = 6;
   public static final int COMMAND_LOAD_URL = 7;
   public static final int COMMAND_FOCUS = 8;
+
+  // android commands
+  public static final int COMMAND_CLEAR_FORM_DATA = 1000;
+  public static final int COMMAND_CLEAR_CACHE = 1001;
+  public static final int COMMAND_CLEAR_HISTORY = 1002;
+
   protected static final String REACT_CLASS = "RNCWebView";
   protected static final String HTML_ENCODING = "UTF-8";
   protected static final String HTML_MIME_TYPE = "text/html";
         break;
       case "LOAD_CACHE_ELSE_NETWORK":
         cacheMode = WebSettings.LOAD_CACHE_ELSE_NETWORK;
-        break;  
+        break;
       case "LOAD_NO_CACHE":
         cacheMode = WebSettings.LOAD_NO_CACHE;
         break;
   @Override
   public @Nullable
   Map<String, Integer> getCommandsMap() {
-    Map map = MapBuilder.of(
-      "goBack", COMMAND_GO_BACK,
-      "goForward", COMMAND_GO_FORWARD,
-      "reload", COMMAND_RELOAD,
-      "stopLoading", COMMAND_STOP_LOADING,
-      "postMessage", COMMAND_POST_MESSAGE,
-      "injectJavaScript", COMMAND_INJECT_JAVASCRIPT,
-      "loadUrl", COMMAND_LOAD_URL
-    );
-    map.put("requestFocus", COMMAND_FOCUS);
-    return map;
+    return MapBuilder.<String, Integer>builder()
+      .put("goBack", COMMAND_GO_BACK)
+      .put("goForward", COMMAND_GO_FORWARD)
+      .put("reload", COMMAND_RELOAD)
+      .put("stopLoading", COMMAND_STOP_LOADING)
+      .put("postMessage", COMMAND_POST_MESSAGE)
+      .put("injectJavaScript", COMMAND_INJECT_JAVASCRIPT)
+      .put("loadUrl", COMMAND_LOAD_URL)
+      .put("requestFocus", COMMAND_FOCUS)
+      .put("clearFormData", COMMAND_CLEAR_FORM_DATA)
+      .put("clearCache", COMMAND_CLEAR_CACHE)
+      .put("clearHistory", COMMAND_CLEAR_HISTORY)
+      .build();
   }
 
   @Override
       case COMMAND_FOCUS:
         root.requestFocus();
         break;
+      case COMMAND_CLEAR_FORM_DATA:
+        root.clearFormData();
+        break;
+      case COMMAND_CLEAR_CACHE:
+        boolean includeDiskFiles = args != null && args.getBoolean(0);
+        root.clearCache(includeDiskFiles);
+        break;
+      case COMMAND_CLEAR_HISTORY:
+        root.clearHistory();
+        break;
     }
   }
 

docs/Reference.md

 - [`reload`](Reference.md#reload)
 - [`stopLoading`](Reference.md#stoploading)
 - [`injectJavaScript`](Reference.md#injectjavascriptstr)
+- [`clearFormData`](Reference.md#clearFormData)
+- [`clearCache`](Reference.md#clearCache)
+- [`clearHistory`](Reference.md#clearHistory)
 
 ---
 
 
 To learn more, read the [Communicating between JS and Native](Guide.md#communicating-between-js-and-native) guide.
 
+### `clearFormData()`
+(android only)
+
+```javascript
+clearFormData();
+```
+Removes the autocomplete popup from the currently focused form field, if present. [developer.android.com reference](https://developer.android.com/reference/android/webkit/WebView.html#clearFormData())
+
+
+### `clearCache(bool)`
+(android only)
+```javascript
+clearCache(true);
+```
+
+Clears the resource cache. Note that the cache is per-application, so this will clear the cache for all WebViews used. [developer.android.com reference](https://developer.android.com/reference/android/webkit/WebView.html#clearCache(boolean))
+
+
+### `clearHistory()`
+(android only)
+```javascript
+clearHistory();
+```
+
+Tells this WebView to clear its internal back/forward list. [developer.android.com reference](https://developer.android.com/reference/android/webkit/WebView.html#clearHistory())
+
 ## Other Docs
 
 Also check out our [Getting Started Guide](Getting-Started.md) and [In-Depth Guide](Guide.md).

src/WebView.android.tsx

   AndroidWebViewProps,
   NativeWebViewAndroid,
   State,
-  RNCWebViewUIManager,
+  RNCWebViewUIManagerAndroid,
 } from './WebViewTypes';
 
 import styles from './WebView.styles';
 
-const UIManager = NotTypedUIManager as RNCWebViewUIManager;
+const UIManager = NotTypedUIManager as RNCWebViewUIManagerAndroid;
 
 const RNCWebView = requireNativeComponent(
   'RNCWebView',
     );
   };
 
+  clearFormData = () => {
+    UIManager.dispatchViewManagerCommand(
+       this.getWebViewHandle(),
+       this.getCommands().clearFormData,
+        undefined,
+    );
+  }
+
+  clearCache = (includeDiskFiles: boolean) => {
+    UIManager.dispatchViewManagerCommand(
+       this.getWebViewHandle(),
+       this.getCommands().clearCache,
+       [includeDiskFiles],
+    );
+  };
+
+  clearHistory = () => {
+    UIManager.dispatchViewManagerCommand(
+       this.getWebViewHandle(),
+       this.getCommands().clearHistory,
+        undefined,
+    );
+  };
+
   /**
    * Injects a javascript string into the referenced WebView. Deliberately does not
    * return a response because using eval() to return a response breaks this method

src/WebView.ios.tsx

   NativeWebViewIOS,
   ViewManager,
   State,
-  RNCWebViewUIManager,
+  RNCWebViewUIManagerIOS,
 } from './WebViewTypes';
 
 import styles from './WebView.styles';
 
-const UIManager = NotTypedUIManager as RNCWebViewUIManager;
+const UIManager = NotTypedUIManager as RNCWebViewUIManagerIOS;
 
 const { resolveAssetSource } = Image;
 const processDecelerationRate = (

src/WebViewTypes.ts

 
 type WebViewCommands = 'goForward' | 'goBack' | 'reload' | 'stopLoading' | 'postMessage' | 'injectJavaScript' | 'loadUrl' | 'requestFocus';
 
-export interface RNCWebViewUIManager extends UIManagerStatic {
+type AndroidWebViewCommands = 'clearHistory' | 'clearCache' | 'clearFormData';
+
+
+
+interface RNCWebViewUIManager<Commands extends string> extends UIManagerStatic {
   getViewManagerConfig: (
-    name: string,
+      name: string,
   ) => {
-    Commands: { [key in WebViewCommands]: number };
+    Commands: {[key in Commands]: number};
   };
 }
 
+export type RNCWebViewUIManagerAndroid = RNCWebViewUIManager<WebViewCommands | AndroidWebViewCommands>
+export type RNCWebViewUIManagerIOS = RNCWebViewUIManager<WebViewCommands>
+
+
+
 type WebViewState = 'IDLE' | 'LOADING' | 'ERROR';
 
 interface BaseState {
   /**
    * https://developer.android.com/reference/android/webkit/WebSettings.html#setCacheMode(int)
    * Set the cacheMode. Possible values are:
-   * 
+   *
    * - `'LOAD_DEFAULT'` (default)
    * - `'LOAD_CACHE_ELSE_NETWORK'`
    * - `'LOAD_NO_CACHE'`
    */
   geolocationEnabled?: boolean;
 
-  
+
   /**
-   * Boolean that sets whether JavaScript running in the context of a file 
-   * scheme URL should be allowed to access content from other file scheme URLs. 
+   * Boolean that sets whether JavaScript running in the context of a file
+   * scheme URL should be allowed to access content from other file scheme URLs.
    * Including accessing content from other file scheme URLs
    * @platform android
    */
   allowFileAccessFromFileURLs?: boolean;
-  
+
   /**
    * Boolean that sets whether JavaScript running in the context of a file
    * scheme URL should be allowed to access content from any origin.