Logging

VWO by default logs all ERROR level messages to your server's console. To gain more control over VWO's logging behavior, you can use the logger parameter in the init configuration.

Logger Properties

Parameter	Type	Description
level	String	Level or Type of error. Could be one of the following: DEBUG, INFO, ERROR, TRACE, WARN
prefix	String	The text that is prefixed to the error messages when logged. Defaults to 'VWO-SDK'.
transport	String	Custom logger implementation

Example 1: Set log level to control verbosity of logs

VWOInitOptions vwoInitOptions = new VWOInitOptions();
vwoInitOptions.setAccountId(123456);
vwoInitOptions.setSdkKey("32-alpha-numeric-sdk-key");

Map<String, Object> logger = new HashMap<>();
logger.put("level", "DEBUG");
vwoInitOptions.setLogger(logger);
VWO vwoInstance = VWO.init(vwoInitOptions);

Example 2: Add custom prefix to log messages for easier identification

VWOInitOptions vwoInitOptions = new VWOInitOptions();
vwoInitOptions.setAccountId(123456);
vwoInitOptions.setSdkKey("32-alpha-numeric-sdk-key");

Map<String, Object> logger = new HashMap<>();
logger.put("level", "DEBUG");
logger.put("prefix", "CUSTOM LOG PREFIX");
vwoInitOptions.setLogger(logger);
VWO vwoInstance = VWO.init(vwoInitOptions);

Example 3: Implement custom transport to handle logs your way
The transports parameter allows you to implement custom logging behavior by providing your own logging functions. You can define handlers for different log levels (debug, info, warn, error, trace) to process log messages according to your needs.

For example, you could:

Send logs to a third-party logging serviceWrite logs to a file
Format log messages differently
Filter or transform log messages
Route different log levels to different destinations

The transport object should implement handlers for the log levels you want to customize. Each handler receives the log message as a parameter.

VWOInitOptions vwoInitOptions = new VWOInitOptions();
vwoInitOptions.setAccountId(123456);
vwoInitOptions.setSdkKey("32-alpha-numeric-sdk-key");

Map<String, Object> logger = new HashMap<>();
logger.put("level", "DEBUG");
logger.put("prefix","your_custom_prefix");

List<Map<String, Object>> transports = new ArrayList<>();
LogTransport logTransport = new LogTransport() {
    @Override
    public void log(LogLevelEnum level, String message) {
        // your custom logging logic here
    }
};
transports.add(new HashMap<String, Object>() {{
    put("defaultTransport", logTransport);
}});
logger.put("transports", transports);
vwoInitOptions.setLogger(logger);
VWO vwoInstance = VWO.init(vwoInitOptions);