HowTo: Enable logging for Smart Devices

Official Content

This document gives the first approach for debugging Smart Devices applications by inspecting log messages.

Step 1 - Enable Log level

The developer must set the Enable Logging property in True (default value), and then indicate the log level to record for each feature. 

This action can be made by setting the following properties at the Smart Device Main object's level:

Step 2 - Run the application

You must build and run your Smart Device application (Main object)

Step 3 - Inspect log messages

Android environment

There are three ways to debug Android applications, all of them by using the LogCat tool.

1) By using command-line tool 
Android provides a command-line tool for inspecting log. For example, by opening a Command Prompt or PowerShell, the developer can create a log file by executing the following command. Note how we are filtering GeneXus applications debug messages (GeneXusApplication:D), Android runtime errors (AndroidRuntime:E) error and every custom message (System.out:I). For more information about command-line tool parameters, refer to LogCat command line tool.
> adb logcat -v brief GeneXusApplication:D AndroidRuntime:E System.out:I *:S > MyLogFile.txt
 In case that you do want to write the result  directly in your console, simply delete "> MyLogFile.txt" from the command.
Logging - Logcat command-line
Note: Requires %ANDROID_HOME% environment variable set (with the path to your Android-SDK directory).

2) By using monitor.bat
Android-SDK provides the  Android Device Monitor, a UI tool for running LogCat. It can be launched by opening monitor.bat script, located in C:/<Android-SDK>/tools
Logging - Logcat - Android Device Monitor
Note: Requires %JAVA_HOME% environment variable set.

3) By using Android Studio
If you are using Android Studio, you can run  Android Device Monitor by navigating from Tools > Android > Android Device Monitor.
Logging - Logcat - Android Studio

iOS environment

There are three ways to check the generated logs in iOS applications.

1) By using XCode Debug Console
The developer should open XCode and run the application from it. Then, log messages will be displayed on the debug Console.
 Logging - XCode - Debug Console

2) By inspecting application log files
The application will generate *.log files in its data path (accessible from Directory.ApplicationDataPath). Then, you can read it from the application and send a report, or simply display its contents on it. The following example displays log files and their contents directly on the application (download it here, and include it in your KB).
Logging - iOS - Read from log file

3) By using logfile from simulator
Once the application is launched in a simulator (e.g. by F5 from GeneXus), the developer can inspect the log by doing Debug > Open System Log... from the system bar (or ⌘+/ shortcut).


  • With iOS applications, instead of setting logging properties with GeneXus, the developer can enable logging by going to Settings > <your_app> and turn on Enable Log switch (and which log level desires).
    Logging - iOS - Application Settings


Platforms  Smart Devices (Android, iOS)

See also

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