Working With ValidFrom and ValidTo
Folders, content references, content reference links, and tab definitions have both ValidFrom and ValidTo dates. What's the difference and how are they used in the portal registry API?
A ValidFrom date is when something begins.
A ValidTo date is when something ends.
For example, suppose your HR department has a page describing the benefits for your employees, and that page changed every calendar year. This means the page for the year 2000 has a ValidFrom date of 01/01/2000 and a ValidTo date of 12/31/2000. The benefits page for the year 2001 has a ValidFrom date of 01/01/2001 and a ValidTo date of 12/31/2001.
Folders, content references, content reference links and tab definitions are returned in their collections regardless of the ValidTo and ValidFrom dates. You must take these dates into account and only display to the end-user those values that should be seen.
In addition, a ValidFrom should always come before a ValidTo date. If they are set incorrectly, you receive a runtime error.
For all newly created folders, content references, content reference links and tab definitions, the default value for both these properties is Null (""), that is, they begin immediately and do not expire.
In addition, you can also check the IsVisible property to see if a portal object is viewable. IsVisible verifies if an object is Hidden, as well as if the ValidTo and ValidFrom dates are within the specified dates.