The Processing Instruction (PI) Macro

The PI (Processing Instruction) macro provides a means of defining the separator text to be inserted between the code pieces (which represent entities) that are generated using a template.

The structure for setting the Processing Instruction is:


In this structure, <value> is a literal string enclosed by double quotes, with the following options:

  • "\n" - New line (the default)
  • " " - Space
  • "\t" - Tab
  • "" - Null

By default, the PI is set to generate a new line (\n) for each non-empty substitution, which behavior can be changed by resetting the PI macro. For instance, a Class’s Attribute declaration in simple VB code would be generated to a single line statement (with no new lines). These properties are derived from the Class-Attribute Properties in the model to generate, for example:

     Private Const PrintFormat As String = "Portrait"

The template for generating this starts with the PI being set to a space rather than a new line:

     % PI = " " %

     % CONVERT_SCOPE ( attScope )%

     % endIf %

     % if attConst == "T" %


     % endIf %

On transforming this, attscope returns the VB keyword 'Private' and attConst returns 'Const' on the same line spaced by a single space (fitting the earlier VB Class.Attribute definition example).

Alternatively, when generating a Class you might want the Class declaration, the notes and Class body all separated by double lines. In this case the %PI is set to '/n/n' to return double line spacing:

     % PI = "\n\n" %

     % ClassDeclaration %

     % ClassNotes %

     % ClassBody %

PI Characteristics

  • Blank lines have no effect on the output
  • Any line that has a macro that produces an empty result does not result in a PI separator (space/new line)
  • The last entry does not return a PI; for example, %Classbody% (above) does not have a double line added after the body

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