[jira] [Commented] (WICKET-3496) Component#setDefaultModelObject should take in account IWrapModel

["Pedro Santos (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/WICKET-3496?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15549238#comment-15549238 ] 

Pedro Santos commented on WICKET-3496:
--------------------------------------

Is there a good reason to keep the instances equality test inside Component#setModelObject?  I'm +1 to remove it. 

A possible use case now that Wicket supports CDI: an user may want to change a component model object from a transient one to an equal one, but managed and with an associated persistence context after to start a long running conversation. In this case it would make sense to simply allow user to user Component#setModelObject and to trigger all the model changing and changed logic it needs.

> Component#setDefaultModelObject should take in account IWrapModel 
> ------------------------------------------------------------------
>
>                 Key: WICKET-3496
>                 URL: https://issues.apache.org/jira/browse/WICKET-3496
>             Project: Wicket
>          Issue Type: Improvement
>          Components: wicket
>    Affects Versions: 1.4.16
>         Environment: Win7, JDK 1.6u23, Jetty 6
>            Reporter: Alexander Morozov
>            Priority: Minor
>         Attachments: myproject.7z
>
>
> Under some conditions, component's model object will not be updated (2), because
> of Component#defaultModelComparator (1). One of such kind of condition is default model that implements
> IWrapModel (see quickstart).
> Component#setDefaultModelObject:
> 		// Check whether this will result in an actual change
> 		if (!getModelComparator().compare(this, object)) //<<<<< 1 >>>>>>
> 		{
> 			modelChanging();
> 			model.setObject(object); //<<<<< 2 >>>>>>
> 			modelChanged();
> 		}
> I suggest that defaultModelComparator can be slightly improved to be able to extract and compare the real ("unwrapped") object,
> for example, by means of Component#getInnermostModel():
> Component#defaultModelComparator:
> 	private static final IModelComparator defaultModelComparator = new IModelComparator()
> 	{
> 		private static final long serialVersionUID = 1L;
> 		public boolean compare(Component component, Object b)
> 		{
> 			// final Object a = component.getDefaultModelObject(); //<<<<< 3 >>>>>>
>                         IModel<?> model = component.getInnermostModel(); // get "real" model
>                         final Object a = model.getObject();
> 			if (a == null && b == null)
> 			{
> 				return true;
> 			}
> 			if (a == null || b == null)
> 			{
> 				return false;
> 			}
> 			return a.equals(b);
> 		}
> 	};



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)