0.6.0 Logger - dynamic control

Firmware
1

How does one turn logging off and on under dynamic program control?

The following program:

SerialLogHandler logHandler;

void setup() {
    delay(2000L);
}

Outputs this:

0000002246 [system] INFO: ARM_WLAN_WD 2
0000002246 [hal.wlan] INFO: Bringing WiFi interface up with DHCP
0000002278 [system] INFO: CLR_WLAN_WD 1, DHCP success
0000002280 [system] INFO: Cloud: connecting
0000002284 [system] INFO: Resolved host device.spark.io to 52.23.193.249
0000002560 [system] INFO: connected to cloud 52.23.193.249:5683
0000002560 [system] INFO: Cloud socket connected
0000003618 [comm] INFO: Hanshake: completed
0000003620 [system] INFO: Cloud connected

which is fine if one wants this output, but if you don't, how do you stop it?

2

You may find some info about the capabilities of the LogHandlers here

3

@ScruffR, this stops the trace output (just like the documentation says it would):

SerialLogHandler logHandler(LOG_LEVEL_NONE, {   // Logging level for non-application messages
        { "app", LOG_LEVEL_NONE },                  // Default logging level for all application messages
        { "app.network", LOG_LEVEL_TRACE },          // Logging level for networking messages
        { "app.setup", LOG_LEVEL_WARN }            // Logging level for setup messages
    });

The question remains however as to how to dynamically change the logging output from a running program, eg by a cloud function. The spark_wiring_logging.h does not give an clues here.

4

I must admit I haven’t done that myself yet, but I’d have thought of class LogManager to be doing that.
But I’ve not checked if that is exposed to user code.

  LogManager::instance()->addHandler(yourHandler);
  LogManager::instance()->removeHandler(yourHandler);
5

Did you have luck with it?

6

@Rikardov,

Yes, it was solved, but not quite in the that way I originally asked for (ie change the log level dynamically at will during the running of the program) because I changed my mind. I now just set it once via a config within Setup() and not change it again.

Am sure that @ScruffR’s suggestion above will work, but I did not need to make it “dynamic” in the end.

// ==== Dynamically set up logger =====

// Get log manager's instance
auto logManager = LogManager::instance();

// Configure and register log handler dynamically
LogCategoryFilters filters;

LogLevel logLevel;

  // Typically set from a config - just showing what options you have here to simplify
  // logLevel = LOG_LEVEL_NONE;
  // logLevel = LOG_LEVEL_ERROR;
  // logLevel = LOG_LEVEL_WARN;
  // logLevel = LOG_LEVEL_INFO;
  // logLevel = LOG_LEVEL_TRACE;
  logLevel = LOG_LEVEL_ALL;

filters.append({ "app", logLevel });   

// Select debug output destination
// -------------------------------
Print *pStream;

if (bUseUSBSerial1)
    pStream = &USBSerial1;
else
    pStream = &Serial;

auto logHandler1 = new StreamLogHandler(*pStream, LOG_LEVEL_WARN /* Default level */, filters);

logManager->addHandler(logHandler1);
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