Welcome to part 1... today we're looking at supporting basic configuration in components without additional coding by using the windsor container.

So - with the container we can provide configuration for a component which is loaded at runtime, so every time you start your app it will be read in - you can do this using the configuration support in .Net - but using castle makes support for this very code-light in comparison... let's take a look.



So first off, we have a class we can use to calculate the tax on a gross ammount:

public class TaxCalculator

{

    private decimal _rate = 0.125m;
    public decimal Rate

    {

        set { _rate = value; }

        get { return _rate; }

    }
    public decimal CalculateTax(decimal gross)

    {

        return Math.Round(_rate*gross, 2);

    }

}

By default the tax rate is 12.5% - but we can change the tax rate by setting the "Rate" property.



Now, lets look at setting up the container... so we have this code in our sample:

private static void Main(string[] args)

{

    WindsorContainer container = new WindsorContainer(new XmlInterpreter());
    TaxCalculator calculator = container.Resolve();
    decimal gross = 100;

    decimal tax = calculator.CalculateTax(gross);
    Console.WriteLine("Gross: {0}, Tax: {1}", gross, tax);

    Console.Read();

}

The windsor container is constructed with an "XmlInterpreter" - this configuration will pull the setup for our container from a section in the App.config.



Let's have a look at that:

  


        type="Castle.Windsor.Configuration.AppDomain.CastleSectionHandler, Castle.Windsor" />

  
  

    

      

    

  

Running the program will display: Gross: 100, Tax: 12.50



Now, what about changing the tax rate in the configuration?

  


        type="Castle.Windsor.Configuration.AppDomain.CastleSectionHandler, Castle.Windsor" />

  
  

    

      

          0.25

        

      

    

  

Now running the program will display: Gross: 100, Tax: 25.00



And that's part 1 done - so now you can see how can we supply configuration parameters, and provide sensible defaults for them.

Next time we'll look at configuring arrays...