SimplePatterns.FunctionExtensions 1.2.0

About

SimplePatterns.FunctionExtensions provides some useful extensions over Action and Func<bool> delegates to hide boiler plate code like try-catch block and retries.

ExecuteWithRetry is an extension defined on Func<bool> delegate that executes the delegate until it is true or for the specified number of retries + 1, whichever is earlier.

WrapInExceptionHandler is an extension defined on Action delegate that wraps the action within the specified exception handler and returns a Func<bool> delegate which can be used with ExecuteWithRetry. An additonal extension of this method is provided for Func<bool> delegate. This is useful for handling multiple exceptions from the action. Though it does not produce an optimized implementation, this approach enhances the code readability as shown below.

Action a = someAction;
a.WrapInExceptionHandler<SomeException>().WrapInExceptionHandler<SomeOtherException>().ExecuteWithRetry(2);

These extensions are useful in scenarios like trying to access a file while it is locked by different process or attempting a DB connection when the connection count has reached maximum. In these scenarios, the same operations can be conveniently retried using the above extensions.

Usage

public void ExecuteWithRetry()
{
    ...
    bool status = ((Func<bool>)executor.Executor)
    .ExecuteWithRetry(retries);
    ...
}

public void WrapInExceptionHandler()
{
    ...
    var status = ((Action)executor.Action)
    .WrapInExceptionHandler<NotImplementedException>()
    .ExecuteWithRetry(retries);
    ...
}

private sealed class MockExecutor
{
    public bool Executor()
    {
        return true;
    }

    public void Action()
    {
        throw new NotImplementedException();
    }
}