Passing constants to predefined blocks with CruiseControl.NET preprocessor

Question

What is the preferred way of "passing" preprocessor constants to predefined blocks in CC.NET?

Assuming I have the following declarations:

<cb:define name="ProjectHeaderBlock">
    <name>$(ProjectName)</name>
    <workingDirectory>C:\MyProjects\$(ProjectName)</workingDirectory>
</cb:define>

<cb:define name="ProjectBlock">
    <project>
        <cb:ProjectHeaderBlock />

        <triggers />
        <tasks />
        <publishers />
    </project>
</cb:define>

I can pass the ProjectName constant in two ways:

1. Using cb:scope

   <cb:scope ProjectName="FooProject" >
       <cb:ProjectBlock />
   </cb:scope>
   

2. Passing directly in declaration

   <cb:ProjectBlock ProjectName="FooProject" />
   

They both worked properly and inner ProjectHeaderBlock was initialized with proper ProjectName value.

Are there any differences between these two options? Which one is better/more efficient?

Answer 1

You're right: They work both. The only functional difference that I'm aware of is that preprocessor contants defined in scope elements are overwritable i.e., they may be redefined later.

I use scope defined preprocessor constants for setting default values which I overwrite if necessary.

Personally I prefer the second version as it avoids nesting in your xml.