fcf::NTest::Logger class

Type:

class fcf::NTest::Logger

Available from version: 1.0.1

A configurable logging utility providing multiple severity levels and customizable output formatting via static prefixes or functional callbacks

Detailed description

The fcf::NTest::Logger class manages diagnostic output through various severity levels. It supports both global access via singleton-like functions and independent logger instances. The logger can be customized with static string prefixes or dynamic functional prefixes (e.g., for timestamps).

The logger filters messages based on the current fcf::NTest::ELogLevel. Only messages with a level equal to or higher than the set threshold are processed.

fcf::NTest::LL_FTL (Fatal), fcf::NTest::LL_ERR (Error), fcf::NTest::LL_WRN (Warning), fcf::NTest::LL_ATT (Attention), fcf::NTest::LL_LOG (Log), fcf::NTest::LL_INF (Info), fcf::NTest::LL_DBG (Debug), fcf::NTest::LL_TRC (Trace).

Usage Examples

1. Basic Logging

Using global shortcut functions for immediate output.

// Default level is LL_LOG fcf::NTest::inf() << "System initialized." << std::endl; fcf::NTest::err() << "Critical error detected!" << std::endl; // Debug messages won't appear unless level is changed fcf::NTest::dbg() << "This is hidden by default." << std::endl;

2. Customizing Prefixes

Adding static strings or dynamic functions (e.g., timestamps) to every log entry.

fcf::NTest::logger().addPrefixStr("[MY_APP] "); // Dynamic functional prefix (e.g., for timestamps) fcf::NTest::logger().addPrefixFunc([](fcf::NTest::Logger& a_logger, fcf::NTest::ELogLevel a_level) { return "[" + fcf::NTest::Logger::toLevelStr(a_level) + "] "; }); fcf::NTest::log() << "Message with custom prefix." << std::endl; // Output: [MY_APP] [log] Message with custom prefix.

3. Changing Log Level

Adjusting verbosity at runtime.

fcf::NTest::logger().levelStr("dbg"); fcf::NTest::dbg() << "Now debug messages are visible." << std::endl; // Or using enum fcf::NTest::logger().levelStr(fcf::NTest::LL_ALL);

Typedef

typedef PrefixFunctionType - Prefix handler functor

Static methods

fcf::NTest::ELogLevel toLevel(std::string a_level, fcf::NTest::ELogLevel a_default = fcf::NTest::LL_LOG)

- Converts a string representation of a log level to its enum value.

const char* toLevelStr()

- Converts an fcf::NTest::ELogLevel enumeration value into its corresponding human-readable string representation.

Methods

[CONSTRUCTOR] Logger()

- Default constructor that initializes a new logger instance with the default log level set to LL_LOG.

fcf::NTest::ELogLevel level()

void level(fcf::NTest::ELogLevel a_level)

- Receive or set the current log level (fcf::NTest::ELogLevel) value depending on the parameters given.

const char* levelStr()

void levelStr(const char* a_level)

- Returns or sets a new log level value in string format

void addPrefixStr(const std::string& a_prefix)

- Appends a static string as a prefix to all subsequent log messages produced by the logger.

void addPrefixFunc(const fcf::NTest::Logger::PrefixFunctionType& a_prefix)

- Adds a dynamic functional prefix to all subsequent log messages, allowing for real-time data injection such as timestamps or thread IDs

std::ostream& ftl()

- Returns a reference to the output stream for fatal-level log messages. This level is used for critical failures that require immediate attention.

std::ostream& err()

- Returns a reference to the output stream for error-level log messages. This level is used to report significant issues that do not necessarily terminate the application

std::stream& wrn()

- Returns a reference to the output stream for warning-level log messages. This level is used for warnings that require immediate attention.

std::stream& att()

- Returns a reference to the output stream for attention-level log messages. This level is used for important message that require attention.

std::stream& log()

- Returns a reference to the output stream for default level log messages. This level is used for simple message that require attention.

std::stream& inf()

- Returns a reference to the output stream for info level log messages. This level is used for message with a secondary importance

std::stream& dbg()

- Returns a reference to the output stream for debug log messages. This logging level is used to output the debugging mesasge.

std::stream& trc()

- Returns a reference to the output stream for trace log messages. This logging level is used to extract tracing data.