Catch and log exceptions in JavascriptInterfaces

src/main/java/org/medicmobile/webapp/mobile/EmbeddedBrowserActivity.java

@@ -63,6 +63,7 @@ public void onReceiveValue(String result) {
 	private SimprintsSupport simprints;
 	private PhotoGrabber photoGrabber;
 
+//> ACTIVITY LIFECYCLE METHODS
 	@Override public void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 
@@ -104,15 +105,6 @@ public void onReceiveValue(String result) {
 		}
 	}
 
-	private void configureUseragent() {
-		String current = container.getUserAgentString();
-
-		if(current.contains(APPLICATION_ID)) return;
-
-		container.setUserAgentString(String.format("%s %s/%s",
-				current, APPLICATION_ID, VERSION_NAME));
-	}
-
 	@Override public boolean onCreateOptionsMenu(Menu menu) {
 		if(settings.allowsConfiguration()) {
 			getMenuInflater().inflate(R.menu.unbranded_web_menu, menu);
@@ -182,6 +174,7 @@ private void configureUseragent() {
 		}
 	}
 
+//> PUBLIC API
 	public void evaluateJavascript(final String js) {
 		container.post(new Runnable() {
 			public void run() {
@@ -200,6 +193,30 @@ public void run() {
 		});
 	}
 
+	public void errorToJsConsole(String message, Object... extras) {
+		jsConsole("error", message, extras);
+	}
+
+	public void logToJsConsole(String message, Object... extras) {
+		jsConsole("log", message, extras);
+	}
+
+//> PRIVATE HELPERS
+	private void jsConsole(String type, String message, Object... extras) {
+		String formatted = String.format(message, extras);
+		String escaped = formatted.replace("'", "\\'");
+		evaluateJavascript("console." + type + "('" + escaped + "');");
+	}
+
+	private void configureUseragent() {
+		String current = container.getUserAgentString();
+
+		if(current.contains(APPLICATION_ID)) return;
+
+		container.setUserAgentString(String.format("%s %s/%s",
+				current, APPLICATION_ID, VERSION_NAME));
+	}
+
 	private void openSettings() {
 		startActivity(new Intent(this,
 				SettingsDialogActivity.class));
@@ -244,7 +261,7 @@ private void setUpUiClient(XWalkView container) {
 				if(photoGrabber.canHandle(acceptType, capture)) {
 					photoGrabber.chooser(callback, capture);
 				} else {
-					evaluateJavascript(String.format("console.log('No file chooser is currently implemented for \"accept\" value: %s');", acceptType));
+					logToJsConsole("No file chooser is currently implemented for \"accept\" value: %s", acceptType);
 					warn(this, "openFileChooser() :: No file chooser is currently implemented for \"accept\" value: %s", acceptType);
 				}
 			}

src/main/java/org/medicmobile/webapp/mobile/MedicAndroidJavascript.java

@@ -9,6 +9,8 @@
 import android.os.Process;
 import android.widget.DatePicker;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.text.DateFormat;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
@@ -21,6 +23,7 @@
 import static java.util.Calendar.MONTH;
 import static java.util.Calendar.YEAR;
 import static java.util.Locale.UK;
+import static org.medicmobile.webapp.mobile.MedicLog.log;
 
 public class MedicAndroidJavascript {
 	private static final String DATE_FORMAT = "yyyy-MM-dd";
@@ -44,6 +47,7 @@ public void setLocationManager(LocationManager locationManager) {
 		this.locationManager = locationManager;
 	}
 
+//> JavascriptInterface METHODS
 	@org.xwalk.core.JavascriptInterface
 	@android.webkit.JavascriptInterface
 	public String getAppVersion() {
@@ -59,14 +63,18 @@ public String getAppVersion() {
 	@org.xwalk.core.JavascriptInterface
 	@android.webkit.JavascriptInterface
 	public void playAlert() {
-		if(soundAlert != null) soundAlert.trigger();
+		try {
+			if(soundAlert != null) soundAlert.trigger();
+		} catch(Exception ex) {
+			logException(ex);
+		}
 	}
 
 	@org.xwalk.core.JavascriptInterface
 	@android.webkit.JavascriptInterface
 	public String getDataUsage() {
-		int uid = Process.myUid();
 		try {
+			int uid = Process.myUid();
 			return new JSONObject()
 					.put("system", getDataUsage(
 							TrafficStats.getTotalRxBytes(),
@@ -117,7 +125,11 @@ public String getLocation() {
 	@org.xwalk.core.JavascriptInterface
 	@android.webkit.JavascriptInterface
 	public void datePicker(final String targetElement) {
-		datePicker(targetElement, Calendar.getInstance());
+		try {
+			datePicker(targetElement, Calendar.getInstance());
+		} catch(Exception ex) {
+			logException(ex);
+		}
 	}
 
 	@org.xwalk.core.JavascriptInterface
@@ -130,6 +142,8 @@ public void datePicker(final String targetElement, String initialDate) {
 			datePicker(targetElement, c);
 		} catch(ParseException ex) {
 			datePicker(targetElement);
+		} catch(Exception ex) {
+			logException(ex);
 		}
 	}
 
@@ -139,21 +153,35 @@ public void datePicker(final String targetElement, String initialDate) {
 	@org.xwalk.core.JavascriptInterface
 	@android.webkit.JavascriptInterface
 	public boolean simprints_available() {
-		return simprints.isAppInstalled();
+		try {
+			return simprints.isAppInstalled();
+		} catch(Exception ex) {
+			logException(ex);
+			return false;
+		}
 	}
 
 	@org.xwalk.core.JavascriptInterface
 	@android.webkit.JavascriptInterface
 	public void simprints_ident(int targetInputId) {
-		simprints.startIdent(targetInputId);
+		try {
+			simprints.startIdent(targetInputId);
+		} catch(Exception ex) {
+			logException(ex);
+		}
 	}
 
 	@org.xwalk.core.JavascriptInterface
 	@android.webkit.JavascriptInterface
 	public void simprints_reg(int targetInputId) {
-		simprints.startReg(targetInputId);
+		try {
+			simprints.startReg(targetInputId);
+		} catch(Exception ex) {
+			logException(ex);
+		}
 	}
 
+//> PRIVATE HELPER METHODS
 	private void datePicker(String targetElement, Calendar initialDate) {
 		// Remove single-quotes from the `targetElement` CSS selecter, as
 		// we'll be using these to enclose the entire string in JS.  We
@@ -185,6 +213,20 @@ public void onDateSet(DatePicker view, int year, int month, int day) {
 		dialog.show();
 	}
 
+	private void logException(Exception ex) {
+		log(ex, "Execption thrown in JavascriptInterface function.");
+
+		StringWriter sw = new StringWriter();
+		PrintWriter pw = new PrintWriter(sw);
+		ex.printStackTrace(pw);
+		String stacktrace = sw.toString()
+				.replace("\n", "; ")
+				.replace("\t", " ");
+
+		parent.errorToJsConsole("Execption thrown in JavascriptInterface function: %s", stacktrace);
+	}
+
+//> STATIC HELPERS
 	private static String jsonError(String message, Exception ex) {
 		return jsonError(message + ex.getClass() + ": " + ex.getMessage());
 	}