Chapter 1: Overview of Content Policy Language
[section_type [label]] [section_condition][section_properties] section_content
where:
•The section_type defines the syntax of the rules used in the section, and the evaluation strategy used to evaluate those rules. The square brackets [ ] surrounding the section name (and optional label) are required.
•The optional label, separated from the section type by space, is a CPL
•The optional section_condition is a list of triggers, all of which must evaluate to true before the section content is evaluated.
•The optional section_properties is a list of properties that will become the default settings for those properties for any rule matched in the section. These override any layer property defaults and can in turn be overridden by explicitly setting a different value for that property in a rule within the section.
•The section_content is a list of rules. A section must contain at least one rule.
Collectively, the section_condition and section_properties are often referred to as a section guard expression.
A layer with sections has the logical form:
if (layer_condition is true) then
{
if (section1_condition is true then
{
if (rule1A_condition is true) then
set layer_properties then section_properties then rule1A properties else if (rule1B_condition is true) then
set layer_properties then section_properties then set rule1B
properties
....
}
else if (section2_condition is true then
{
if (rule2A_condition is true) then
set layer_properties then section_properties then rule2A properties else ...
}
...
}
Definitions
Two types of definitions are used in CPL:
•Named definitions that are explicitly referenced by policy
•Anonymous definitions that apply to all policy evaluation and are not referenced directly in rules.
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