constraint-field

Specifies a cacheability constraint for the given url-pattern or servlet-name.

All constraint-field constraints must pass for a response to be cached. If there are value constraints, at least one of them must pass.

Subelements

The following table describes subelements for the constraint-field element. The left column lists the subelement name, the middle column indicates the requirement rule, and the right column describes what the element does.

Table 6–37 constraint-field Subelements

Element	Required	Description
value	zero or more	Contains a value to be matched to the input parameter value.

Attributes

The following table describes attributes for the constraint-field element. The left column lists the attribute name, the middle column indicates the default value, and the right column describes what the attribute does.

Table 6–38 constraint-field Attributes

Attribute	Default Value	Description
name	none	Specifies the input parameter name.
scope	request.parameter	(optional) Specifies the scope in which the input parameter can be present. Allowed values are context.attribute, request.header, request.parameter, request.cookie, session.id, and session.attribute.
cache-on-match	true	(optional) If true, caches the response if matching succeeds. Overrides the same attribute in a value subelement.
cache-on-match-failure	false	(optional) If true, caches the response if matching fails. Overrides the same attribute in a value subelement.