[WICKET-6946] isVisibleInHierarchy/isEnabledInHierarchy broken by isVisible/isEnabled override

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 10.0.0-M1, 9.8.0
• Component/s: wicket-core
• Assignee: Sven Meier
• Reporter: Mathieu Mitchell
• Created: 18/Jan/22 20:49
• Updated: 25/Feb/22 12:17
• Resolved: 20/Jan/22 15:03

Description

Currently, isVisibleInHierarchy and isEnabledInHierarchy can return invalid values when isVisible or isEnabled is overridden. The problem is caused by the caching done in isVisibleInHierarchy/isEnabledInHierarchy. Currently, the cache is invalidated in setVisible/setEnabled. The cache invalidation is not done when components are overriding isVisible/isEnabled.

Additionally, the documentation mentions impacts of overriding isVisible/isEnabled when using "non-trivial" code, as the methods are called multiple times and can slow down page rendering.
The best practices chapter mentions overriding isVisible/isEnabled as the appropriate approach. Another best practices page mentions that a component factory should not be used because it prevents overriding isVisible/isEnabled in an anonymous class.

There is no clear warning that overriding isVisible/isEnabled can break isVisibleInHierarchy/isEnabledInHierarchy when the returned value can change.

There is also no indication that overriding isVisible/isEnabled is not recommended.

Issue Links

• links to: GitHub Pull Request #493