dev-11 / aop_logging

An AOP way of logging in dotnet core

aop_logging

A Simple aspect oriented logger

The type T, what we want to decorate with logging, has to implement an interface, cannot be sealed, and cannot be abstract as these are the precondition of the System.Reflection.DispatchProxyGenerator.GenerateProxyType(Type baseType, Type interfaceType) method.

Main Interfaces:

ILogger

The ILogger interface has just a single function: void Log(LogEntry logEntry). How the logging exactly happens is up to the user.

ILogEntryBuilder

Right now the code logs 3 type of events: Invoke, Leave, and Exception. Every event generates a LogEntry which will be logged by the ILogger. There is a default implementation of the ILogEntryBuilder which can be easily replaced by a custom implementation of the ILogEntryBuilder interface.

Example Usage

var calc = LoggingProxy<ICalculator>.Create(new Calculator(),
                                            new ConsoleLogger(),
                                            new LogEntryBuilder());

calc.Add(1, 2);
calc.Divide(12, 0);

If we decorate T with the LoggingProxy the logging will be completely automatic.

Sample output of ConsoleLogger

07/19/2019 19:32:35|Information|Invoke|ClassName: AopLoggingConsole.Calculator, Method: Add, Args: 1, 2
07/19/2019 19:32:35|Information|Leave|ClassName: AopLoggingConsole.Calculator, Method: Add, Args: 1, 2, Return type: System.Int32, Return value: 3
07/19/2019 19:32:36|Error|Exception|ClassName: AopLoggingConsole.Calculator, Method: Divide, Args: 12, 0, Exception: System.DivideByZeroException: Attempted to divide by zero.
   at AopLoggingConsole.Calculator.Divide(Int32 a, Int32 b) in /Users/otto/Source/GitHub/aop_logging/AopLoggingConsole/Calculator.cs:line 12

Unhandled Exception: System.DivideByZeroException: Attempted to divide by zero.
   at AopLogging.LoggingProxy`1.Invoke(MethodInfo targetMethod, Object[] args) in /Users/ottogal/Work/SideProjects/GitHub/aop_logging/AopLogging/LoggingProxy.cs:line 34
--- End of stack trace from previous location where exception was thrown ---
   at System.Reflection.DispatchProxyGenerator.Invoke(Object[] args)
   at generatedProxy_1.Divide(Int32 , Int32 )
   at AopLoggingConsole.Program.Main(String[] args) in /Users/Otto/Source/GitHub/aop_logging/AopLoggingConsole/Program.cs:line 18