[MYFACES-2915] UIComponent attribute defaults are not used when bound to managed bean property by EL, even if the managed bean property is null

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Abandoned
• Affects Version/s: 2.0.1
• Component/s: JSR-314
• Assignee: Unassigned
• Reporter: Hanspeter Dünnenberger
• Created: 10/Sep/10 15:37
• Updated: 25/Aug/17 21:29
• Resolved: 25/Aug/17 21:29

Description

As asked by Leonardo I open this issue in relation to issue https://javaserverfaces.dev.java.net/issues/show_bug.cgi?id=1805 on mojarra to check if MyFaces can do the same. For full description see issue above, short description below:

Assigning a UIComponent attribute with EL expression disables the default value handling that some attribute feature (e.g. rendered==null is the same as rendered==true). Since EL expression never evaluates to null an expression like rendered="#

{bean.rendered}

with bean.rendered=null will evaluate to False, since for the rendered attribute the expected type for the ValueExpression is Boolean.
The proposed change would be to use Object as expected type to allow null evaluation from EL and convert to the really expected type later in TagValueExpression. For details see original issue 1805 on mojarra.