[MYFACES-334] aliasbean and alias usage in binding

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.9m9
• Assignee: Martin Marinschek
• Reporter: Mario Ivankovits
• Created: 15/Jul/05 14:56
• Updated: 17/Apr/06 20:50
• Resolved: 08/Mar/06 00:00

Description

Myfaces fails to restore a view it it uses aliases in bindings.

Our jsf looks like this (for sure, we use include for the dataTable):

<x:aliasBeansScope>
<x:aliasBean alias="#

{coTopicEdit}

" value="#

{coAddressEdit}

" />
<h:dataTable var="topic" value="#

{coTopicEdit.topics}

"
binding="#

{coTopicEdit.genericTopicTable}" >
....
</h:dataTable>
<h:commandLink value="xx"/>
</x:aliasBeansScope>


The page renders correctly for the first time, but if you press the commandLink myfaces fails in the restoreView phase.
The reason is simple:
During LifecycleImpl.restoreView myfaces tries to attach each component to the backing bean (in recursivelyHandleComponentReferencesAndSetValid - "binding.setValue").
Now if it comes to the binding of the dataTable the alias bean havent had the chance to reassign its alias and thus the ValueBinding for "#{coTopicEdit.genericTopicTable}

" fails.

To workaround it I create my own ViewHandler (code follows).
I hooked into restoreView - process the view recursivley and call "makeAlias" on each alias bean using reflection (the method is package private).
This IS a hack and (I think) it breaks the scope of the alias , but for now I am happy with it.

Any ideas how to solve it correctly?

And now the code in case someone else needs it too:

public UIViewRoot restoreView(FacesContext facesContext, String viewId)
{
UIViewRoot root = super.restoreView(facesContext, viewId);
if (root != null)

{ processAliases(facesContext, root); }

return root;
}

protected void processAliases(FacesContext context, UIComponent root)
{
if (root == null)

{ return; }

for (Iterator it = root.getFacetsAndChildren(); it.hasNext(); )
{
UIComponent component = (UIComponent)it.next();

if (component instanceof AliasBean)
{
AliasBean alias = (AliasBean) component;
try

{ Method makeAliasMethod = alias.getClass().getDeclaredMethod("makeAlias", FacesContext.class); makeAliasMethod.setAccessible(true); makeAliasMethod.invoke(alias, context); }

catch (NoSuchMethodException e)

{ log.warn(e.getLocalizedMessage(), e); }
catch (IllegalAccessException e)
{ log.warn(e.getLocalizedMessage(), e); }

catch (InvocationTargetException e)

{ log.warn(e.getLocalizedMessage(), e); }

}

processAliases(context, component);
}
}