private void ManyDecoratorsSolution(List <KeyValuePair <string, string> > pairs)
{
var operation = new SimpleOperation();
var metricDecorator = new MetricsDecorator(operation);
var errorHandlingDecorator = new ErrorHandlingDecorator(metricDecorator);
//Note that the ordering of your decorators matters. If you want to clock everything,
//including the error handling, then your metric decorator should be last. But if you
//want your error handling to cover any potential problems with the metrics, error handling
//should be your last decoration and so on...
var result = errorHandlingDecorator.DoOperation(pairs);
Console.WriteLine($"Return from the multiple decorators is {result}");
}
public void Run()
{
var pairs = new List <KeyValuePair <string, string> >
{
new KeyValuePair <string, string>("key1", "value1"),
new KeyValuePair <string, string>("key2", "value2")
};
//The original operator handles all of the metrics, error handline, etc, along with its normal intended function
var originalOperator = new OriginalOperation();
var result1 = originalOperator.DoOperation(pairs);
Console.WriteLine($"Return from concrete call: {result1}");
Console.WriteLine();
//The simple operator is passed to a decorator of our choosing, to add (or decorate) additional functionality
//around the specific action we care about. This separates the concerns of the Operation from other shared concerns
//that other Operations might similarly have, like: validation, logging, error handling, metrics, etc...
var simpleOperation1 = new SimpleOperation();
var metricDecorator = new MetricsDecorator(simpleOperation1);
var result2 = metricDecorator.DoOperation(pairs);
Console.WriteLine($"Return from metric decorator: {result2}");
Console.WriteLine();
var simpleOperation2 = new SimpleOperation();
var errorHandlingDecorator = new ErrorHandlingDecorator(simpleOperation2);
var result3 = errorHandlingDecorator.DoOperation(pairs);
Console.WriteLine($"Return from error handling decorator: {result3}");
Console.WriteLine();
//What if we wanted to both get the metrics and handle any potential errors?
//Do we need another decorator for that? Maybe an ErrorHandlingAndMetricsDecorator?
//Think of a way to solve this, and then look at the below method to see how I solved it.
ManyDecoratorsSolution(pairs);
}
