libphobos/src/std/logger/nulllogger.d

   1 // Written in the D programming language.
   2 /**
   3 Source: $(PHOBOSSRC std/logger/nulllogger.d)
   4 */
   5 module std.logger.nulllogger;
   6
   7 import std.logger.core;
   8
   9 /** The `NullLogger` will not process any log messages.
  10
  11 In case of a log message with `LogLevel.fatal` nothing will happen.
  12 */
  13 class NullLogger : Logger
  14 {
  15     /** The default constructor for the `NullLogger`.
  16
  17     Independent of the parameter this Logger will never log a message.
  18
  19     Params:
  20       lv = The `LogLevel` for the `NullLogger`. By default the `LogLevel`
  21       for `NullLogger` is `LogLevel.all`.
  22     */
  23     this(const LogLevel lv = LogLevel.all) @safe
  24     {
  25         super(lv);
  26         this.fatalHandler = delegate() {};
  27     }
  28
  29     override protected void writeLogMsg(ref LogEntry payload) @safe @nogc
  30     {
  31     }
  32 }
  33
  34 ///
  35 @safe unittest
  36 {
  37     import std.logger.core : LogLevel;
  38     auto nl1 = new NullLogger(LogLevel.all);
  39     nl1.info("You will never read this.");
  40     nl1.fatal("You will never read this, either and it will not throw");
  41 }