ViewHelper Documentation
v:once.instance
Once: Instance
Displays nested content or "then" child once per instance of the content element or plugin being rendered, as identified by the contentObject UID (or globally if no contentObject is associated).
"Once"-style ViewHelpers are purposed to only display their nested content once per XYZ, where the XYZ depends on the specific type of ViewHelper (session, cookie etc).
In addition the ViewHelper is a ConditionViewHelper, which means you can utilize the f:then and f:else child nodes as well as the "then" and "else" arguments.
Arguments
then anySimpleType
Value to be returned if the condition if met.
else anySimpleType
Value to be returned if the condition if not met.
condition boolean
Condition expression conforming to Fluid boolean rules
identifier string
Identity of this condition - if used in other places, the condition applies to the same identity in the storage (i.e. cookie name or session key)
lockToDomain boolean
If TRUE, locks this condition to a specific domain, i.e. the storage of $identity is associated with a domain. If same identity is also used without domain lock, it matches any domain locked condition
ttl integer
Time-to-live for skip registration, number of seconds. After this expires the registration is unset