[jira] [Resolved] (WICKET-3568) New methods to ease migration to onConfigure

["Martin Grigorov (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/WICKET-3568?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Martin Grigorov resolved WICKET-3568.
-------------------------------------

    Resolution: Won't Fix

#onConfigure() is around since 1.4.16 and apps should already use it widely.
There is no activity in the ticket for one year and a half. Closing it.
                
> New methods to ease migration to onConfigure
> --------------------------------------------
>
>                 Key: WICKET-3568
>                 URL: https://issues.apache.org/jira/browse/WICKET-3568
>             Project: Wicket
>          Issue Type: Improvement
>          Components: wicket
>    Affects Versions: 1.4.16, 1.5-RC2
>            Reporter: Emond Papegaaij
>
> We are trying to migrate our projects from overriding isVisible and isEnabled to the new onConfigure method, but are having some problems with the new API. 
> I'll start with explaining the old situation. We find it good practice to always call super.isVisible() in an overriding isVisible method. A typical implementation would look like this:
> public class MyComponent extends WebMarkupContainer {
>   public boolean isVisible() {
>     return super.isVisible() && isConditionSatisfied();
>   }
> }
> Doing things this way, ensures the component will never be visible when the condition is not satisfied, nor when the component is explicitly hidden with setVisible(false).
> Trying to convert this to the new API, we started with:
> public class MyComponent extends WebMarkupContainer {
>   protected void onConfigure() {
>     super.onConfigure();
>     setVisible(isVisible() && isConditionSatisfied());
>   }
> }
> However, we soon realized this will not work because a hidden component can never become visible again. Even when the condition is satisfied, isVisible() will still be false, causing the component to remain hidden. Therefore, our second attempt was to remove the call to isVisible():
> public class MyComponent extends WebMarkupContainer {
>   protected void onConfigure() {
>     super.onConfigure();
>     setVisible(isConditionSatisfied());
>   }
> }
> This, however, suffers from another problem: manual setVisible(...) calls are now ignored. The visibility flag is always overridden by onConfigure. On our third attempt, we decided to use the visibilityAllowed flag for onConfigure, like this:
> public class MyComponent extends WebMarkupContainer {
>   protected void onConfigure() {
>     super.onConfigure();
>     setVisibilityAllowed(isConditionSatisfied());
>   }
> }
> This works great. It mixes with calls to setVisible. It even mixes well with isVisible overrides in subclasses. However, this approach only works for component visibility. There is no setEnabledAllowed. There is a isEnableAllowed(), but it is security related (the counterpart of isRenderAllowed()). 
> Would it be possible to add a new property to Component (both in 1.4 and 1.5): enabledAllowed? This property would have a final getter (isEnabledAllowed) and setter (setEnabledAllowed), just as with visibilityAllowed. The naming of isEnableAllowed() would be a bit unfortunate, but I don't think that method can be changed. It is part of the public API. This new property would make it significantly easier to move to onConfigure.

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