Parameters and variables can be declared and referenced in the SPS. The difference between the two is that while a variable's value is defined when it is declared, a parameter can have a value passed to it (at run-time via the command line) that overrides the optional default value assigned when the parameter was declared.
In this section, we describe the functionality available for parameters and variables:
•User-Declared Parameters explains how user-defined parameters can be used in an SPS.
•Parameters for Design Fragments describes how parameters can be used with design fragments.
•SPS Parameters for Sources are a special type of parameter. They are automatically defined by StyleVision for schema sources (specifically, the Working XML Files of schemas). Since the name and value of such a parameter are known to the user, the parameter can be referenced within the SPS and a value passed to it at run-time from the command line.
•Variables enable you to: (i) declare a variable with a certain scope and define its value, and (ii) to reference the value of declared variables and create a template on a node or nodes selected by the variable.