Merge pull request #276 from q-m/feature/beforeload-event

CB-14188: Add beforeload event, catching navigation before it happens

Author: Chris Brody

README.md

@@ -115,6 +115,7 @@ instance, or the system browser.
     Android supports these additional options:
 
     - __hidden__: set to `yes` to create the browser and load the page, but not show it. The loadstop event fires when loading is complete. Omit or set to `no` (default) to have the browser open and load normally.
+    - __beforeload__: set to `yes` to enable the `beforeload` event to modify which pages are actually loaded in the browser.
     - __clearcache__: set to `yes` to have the browser's cookie cache cleared before the new window is opened
     - __clearsessioncache__: set to `yes` to have the session cookie cache cleared before the new window is opened
     - __closebuttoncaption__: set to a string to use as the close button's caption instead of a X. Note that you need to localize this value yourself.
@@ -137,6 +138,7 @@ instance, or the system browser.
     iOS supports these additional options:
 
     - __hidden__: set to `yes` to create the browser and load the page, but not show it. The loadstop event fires when loading is complete. Omit or set to `no` (default) to have the browser open and load normally.
+    - __beforeload__: set to `yes` to enable the `beforeload` event to modify which pages are actually loaded in the browser.
     - __clearcache__: set to `yes` to have the browser's cookie cache cleared before the new window is opened
     - __clearsessioncache__: set to `yes` to have the session cookie cache cleared before the new window is opened    
     - __closebuttoncolor__: set as a valid hex color string, for example: `#00ff00`, to change from the default __Done__ button's color. Only applicable if toolbar is not disabled.
@@ -217,6 +219,7 @@ The object returned from a call to `cordova.InAppBrowser.open` when the target i
   - __loadstop__: event fires when the `InAppBrowser` finishes loading a URL.
   - __loaderror__: event fires when the `InAppBrowser` encounters an error when loading a URL.
   - __exit__: event fires when the `InAppBrowser` window is closed.
+  - __beforeload__: event fires when the `InAppBrowser` decides whether to load an URL or not (only with option `beforeload=yes`).
 
 - __callback__: the function that executes when the event fires. The function is passed an `InAppBrowserEvent` object as a parameter.
 
@@ -230,7 +233,7 @@ function showHelp(url) {
 
     var target = "_blank";
 
-    var options = "location=yes,hidden=yes";
+    var options = "location=yes,hidden=yes,beforeload=yes";
 
     inAppBrowserRef = cordova.InAppBrowser.open(url, target, options);
 
@@ -240,6 +243,8 @@ function showHelp(url) {
 
     inAppBrowserRef.addEventListener('loaderror', loadErrorCallBack);
 
+    inAppBrowserRef.addEventListener('beforeload', beforeloadCallBack);
+
 }
 
 function loadStartCallBack() {
@@ -288,6 +293,20 @@ function executeScriptCallBack(params) {
 
 }
 
+function beforeloadCallback(params, callback) {
+
+    if (params.url.startsWith("http://www.example.com/")) {
+
+        // Load this URL in the inAppBrowser.
+        callback(params.url);
+    } else {
+
+        // The callback is not invoked, so the page will not be loaded.
+        $('#status-message').text("This browser only opens pages on http://www.example.com/");
+    }
+
+}
+
 ```
 
 ### InAppBrowserEvent Properties

src/android/InAppBrowser.java

@@ -110,6 +110,7 @@ public class InAppBrowser extends CordovaPlugin {
     private static final String HIDE_URL = "hideurlbar";
     private static final String FOOTER = "footer";
     private static final String FOOTER_COLOR = "footercolor";
+    private static final String BEFORELOAD = "beforeload";
 
     private static final List customizableOptions = Arrays.asList(CLOSE_BUTTON_CAPTION, TOOLBAR_COLOR, NAVIGATION_COLOR, CLOSE_BUTTON_COLOR, FOOTER_COLOR);
 
@@ -138,6 +139,7 @@ public class InAppBrowser extends CordovaPlugin {
     private boolean hideUrlBar = false;
     private boolean showFooter = false;
     private String footerColor = "";
+    private boolean useBeforeload = false;
     private String[] allowedSchemes;
 
     /**
@@ -246,6 +248,20 @@ else if (SYSTEM.equals(target)) {
         else if (action.equals("close")) {
             closeDialog();
         }
+        else if (action.equals("loadAfterBeforeload")) {
+            if (!useBeforeload) {
+              LOG.e(LOG_TAG, "unexpected loadAfterBeforeload called without feature beforeload=yes");
+            }
+            final String url = args.getString(0);
+            this.cordova.getActivity().runOnUiThread(new Runnable() {
+                @SuppressLint("NewApi")
+                @Override
+                public void run() {
+                    ((InAppBrowserClient)inAppWebView.getWebViewClient()).waitForBeforeload = false;
+                    inAppWebView.loadUrl(url);
+                }
+            });
+        }
         else if (action.equals("injectScriptCode")) {
             String jsWrapper = null;
             if (args.getBoolean(1)) {
@@ -674,6 +690,10 @@ public String showWebPage(final String url, HashMap<String, String> features) {
             if (footerColorSet != null) {
                 footerColor = footerColorSet;
             }
+            String beforeload = features.get(BEFORELOAD);
+            if (beforeload != null) {
+                useBeforeload = beforeload.equals("yes") ? true : false;
+            }
         }
 
         final CordovaWebView thatWebView = this.webView;
@@ -924,7 +944,7 @@ public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType)
                     }
 
                 });
-                WebViewClient client = new InAppBrowserClient(thatWebView, edittext);
+                WebViewClient client = new InAppBrowserClient(thatWebView, edittext, useBeforeload);
                 inAppWebView.setWebViewClient(client);
                 WebSettings settings = inAppWebView.getSettings();
                 settings.setJavaScriptEnabled(true);
@@ -1085,16 +1105,20 @@ public void onActivityResult(int requestCode, int resultCode, Intent intent) {
     public class InAppBrowserClient extends WebViewClient {
         EditText edittext;
         CordovaWebView webView;
+        boolean useBeforeload;
+        boolean waitForBeforeload;
 
         /**
          * Constructor.
          *
          * @param webView
          * @param mEditText
          */
-        public InAppBrowserClient(CordovaWebView webView, EditText mEditText) {
+        public InAppBrowserClient(CordovaWebView webView, EditText mEditText, boolean useBeforeload) {
             this.webView = webView;
             this.edittext = mEditText;
+            this.useBeforeload = useBeforeload;
+            this.waitForBeforeload = useBeforeload;
         }
 
         /**
@@ -1107,12 +1131,27 @@ public InAppBrowserClient(CordovaWebView webView, EditText mEditText) {
          */
         @Override
         public boolean shouldOverrideUrlLoading(WebView webView, String url) {
+            boolean override = false;
+
+            // On first URL change, initiate JS callback. Only after the beforeload event, continue.
+            if (this.waitForBeforeload) {
+                try {
+                    JSONObject obj = new JSONObject();
+                    obj.put("type", "beforeload");
+                    obj.put("url", url);
+                    sendUpdate(obj, true);
+                    return true;
+                } catch (JSONException ex) {
+                    LOG.e(LOG_TAG, "URI passed in has caused a JSON error.");
+                }
+            }
+
             if (url.startsWith(WebView.SCHEME_TEL)) {
                 try {
                     Intent intent = new Intent(Intent.ACTION_DIAL);
                     intent.setData(Uri.parse(url));
                     cordova.getActivity().startActivity(intent);
-                    return true;
+                    override = true;
                 } catch (android.content.ActivityNotFoundException e) {
                     LOG.e(LOG_TAG, "Error dialing " + url + ": " + e.toString());
                 }
@@ -1121,7 +1160,7 @@ public boolean shouldOverrideUrlLoading(WebView webView, String url) {
                     Intent intent = new Intent(Intent.ACTION_VIEW);
                     intent.setData(Uri.parse(url));
                     cordova.getActivity().startActivity(intent);
-                    return true;
+                    override = true;
                 } catch (android.content.ActivityNotFoundException e) {
                     LOG.e(LOG_TAG, "Error with " + url + ": " + e.toString());
                 }
@@ -1152,7 +1191,7 @@ else if (url.startsWith("sms:")) {
                     intent.putExtra("address", address);
                     intent.setType("vnd.android-dir/mms-sms");
                     cordova.getActivity().startActivity(intent);
-                    return true;
+                    override = true;
                 } catch (android.content.ActivityNotFoundException e) {
                     LOG.e(LOG_TAG, "Error sending sms " + url + ":" + e.toString());
                 }
@@ -1173,7 +1212,7 @@ else if (!url.startsWith("http:") && !url.startsWith("https:") && url.matches("^
                                 obj.put("type", "customscheme");
                                 obj.put("url", url);
                                 sendUpdate(obj, true);
-                                return true;
+                                override = true;
                             } catch (JSONException ex) {
                                 LOG.e(LOG_TAG, "Custom Scheme URI passed in has caused a JSON error.");
                             }
@@ -1182,7 +1221,10 @@ else if (!url.startsWith("http:") && !url.startsWith("https:") && url.matches("^
                 }
             }
 
-            return false;
+            if (this.useBeforeload) {
+                this.waitForBeforeload = true;
+            }
+            return override;
         }
 
 
@@ -1304,4 +1346,4 @@ public void onReceivedHttpAuthRequest(WebView view, HttpAuthHandler handler, Str
             super.onReceivedHttpAuthRequest(view, handler, host, realm);
         }
     }
-}
+}

src/ios/CDVInAppBrowser.h

@@ -30,7 +30,11 @@
 @class CDVInAppBrowserViewController;
 
 @interface CDVInAppBrowser : CDVPlugin {
-  UIWindow * tmpWindow;
+    UIWindow * tmpWindow;
+
+    @private
+    BOOL _useBeforeload;
+    BOOL _waitForBeforeload;
 }
 
 @property (nonatomic, retain) CDVInAppBrowserViewController* inAppBrowserViewController;
@@ -42,6 +46,7 @@
 - (void)injectScriptCode:(CDVInvokedUrlCommand*)command;
 - (void)show:(CDVInvokedUrlCommand*)command;
 - (void)hide:(CDVInvokedUrlCommand*)command;
+- (void)loadAfterBeforeload:(CDVInvokedUrlCommand*)command;
 
 @end
 
@@ -70,6 +75,7 @@
 @property (nonatomic, assign) BOOL suppressesincrementalrendering;
 @property (nonatomic, assign) BOOL hidden;
 @property (nonatomic, assign) BOOL disallowoverscroll;
+@property (nonatomic, assign) BOOL beforeload;
 
 + (CDVInAppBrowserOptions*)parseOptions:(NSString*)options;
 

src/ios/CDVInAppBrowser.m

@@ -46,6 +46,8 @@ - (void)pluginInitialize
 {
     _previousStatusBarStyle = -1;
     _callbackIdPattern = nil;
+    _useBeforeload = NO;
+    _waitForBeforeload = NO;
 }
 
 - (id)settingForKey:(NSString*)key
@@ -209,6 +211,10 @@ - (void)openInInAppBrowser:(NSURL*)url withOptions:(NSString*)options
         self.inAppBrowserViewController.webView.suppressesIncrementalRendering = browserOptions.suppressesincrementalrendering;
     }
 
+    // use of beforeload event
+    _useBeforeload = browserOptions.beforeload;
+    _waitForBeforeload = browserOptions.beforeload;
+
     [self.inAppBrowserViewController navigateTo:url];
     if (!browserOptions.hidden) {
         [self show:nil];
@@ -304,6 +310,27 @@ - (void)openInSystem:(NSURL*)url
     }
 }
 
+- (void)loadAfterBeforeload:(CDVInvokedUrlCommand*)command
+{
+    NSString* urlStr = [command argumentAtIndex:0];
+
+    if (!_useBeforeload) {
+        NSLog(@"unexpected loadAfterBeforeload called without feature beforeload=yes");
+    }
+    if (self.inAppBrowserViewController == nil) {
+        NSLog(@"Tried to invoke loadAfterBeforeload on IAB after it was closed.");
+        return;
+    }
+    if (urlStr == nil) {
+        NSLog(@"loadAfterBeforeload called with nil argument, ignoring.");
+        return;
+    }
+
+    NSURL* url = [NSURL URLWithString:urlStr];
+    _waitForBeforeload = NO;
+    [self.inAppBrowserViewController navigateTo:url];
+}
+
 // This is a helper method for the inject{Script|Style}{Code|File} API calls, which
 // provides a consistent method for injecting JavaScript code into the document.
 //
@@ -413,6 +440,7 @@ - (BOOL)webView:(UIWebView*)theWebView shouldStartLoadWithRequest:(NSURLRequest*
 {
     NSURL* url = request.URL;
     BOOL isTopLevelNavigation = [request.URL isEqual:[request mainDocumentURL]];
+    BOOL shouldStart = YES;
 
     // See if the url uses the 'gap-iab' protocol. If so, the host should be the id of a callback to execute,
     // and the path, if present, should be a JSON-encoded value to pass to the callback.
@@ -440,11 +468,22 @@ - (BOOL)webView:(UIWebView*)theWebView shouldStartLoadWithRequest:(NSURLRequest*
             return NO;
         }
     }
+
+    // When beforeload=yes, on first URL change, initiate JS callback. Only after the beforeload event, continue.
+    if (_waitForBeforeload && isTopLevelNavigation) {
+        CDVPluginResult* pluginResult = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK
+                                                      messageAsDictionary:@{@"type":@"beforeload", @"url":[url absoluteString]}];
+        [pluginResult setKeepCallback:[NSNumber numberWithBool:YES]];
+
+        [self.commandDelegate sendPluginResult:pluginResult callbackId:self.callbackId];
+        return NO;
+    }
+
     //if is an app store link, let the system handle it, otherwise it fails to load it
-    else if ([[ url scheme] isEqualToString:@"itms-appss"] || [[ url scheme] isEqualToString:@"itms-apps"]) {
+    if ([[ url scheme] isEqualToString:@"itms-appss"] || [[ url scheme] isEqualToString:@"itms-apps"]) {
         [theWebView stopLoading];
         [self openInSystem:url];
-        return NO;
+        shouldStart = NO;
     }
     else if ((self.callbackId != nil) && isTopLevelNavigation) {
         // Send a loadstart event for each top-level navigation (includes redirects).
@@ -455,7 +494,11 @@ - (BOOL)webView:(UIWebView*)theWebView shouldStartLoadWithRequest:(NSURLRequest*
         [self.commandDelegate sendPluginResult:pluginResult callbackId:self.callbackId];
     }
 
-    return YES;
+    if (_useBeforeload && isTopLevelNavigation) {
+        _waitForBeforeload = YES;
+    }
+
+    return shouldStart;
 }
 
 - (void)webViewDidStartLoad:(UIWebView*)theWebView

www/inappbrowser.js

@@ -33,6 +33,7 @@
 
     function InAppBrowser () {
         this.channels = {
+            'beforeload': channel.create('beforeload'),
             'loadstart': channel.create('loadstart'),
             'loadstop': channel.create('loadstop'),
             'loaderror': channel.create('loaderror'),
@@ -44,9 +45,17 @@
     InAppBrowser.prototype = {
         _eventHandler: function (event) {
             if (event && (event.type in this.channels)) {
-                this.channels[event.type].fire(event);
+                if (event.type === 'beforeload') {
+                    this.channels[event.type].fire(event, this._loadAfterBeforeload);
+                } else {
+                    this.channels[event.type].fire(event);
+                }
             }
         },
+        _loadAfterBeforeload: function (strUrl) {
+            strUrl = urlutil.makeAbsolute(strUrl);
+            exec(null, null, 'InAppBrowser', 'loadAfterBeforeload', [strUrl]);
+        },
         close: function (eventname) {
             exec(null, null, 'InAppBrowser', 'close', []);
         },