[TAP5-1642] A mixin parameter that is required but also provides a default property results in an "unbound parameter" exception, starting in Tapestry 5.3

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.3
• Fix Version/s: 5.3
• Component/s: tapestry-core
• Assignee: Howard Lewis Ship
• Reporter: Laurent Guerin
• Created: 12/Sep/11 21:52
• Updated: 24/Oct/11 18:46
• Resolved: 24/Oct/11 18:17

Description

In our Tapestry 5 library (exanpe-t5-lib), we provide some mixins containing some parameters declared as "required=true" AND with a default value.
These parameters are required for the operation of the mixin.

For example, in a Dialog mixin, we have :

@Parameter(value = "confirm", required = true, allowNull = false, defaultPrefix = BindingConstants.LITERAL)
private DialogRenderModeEnum renderMode;

If this required parameter is not explicity bound in the TML :

• In 5.2.6, everything is ok : the default value is used
• In 5.3-beta-5, we get the following Exception :
  Parameter(s) 'Dialog.renderMode' are required for org.apache.tapestry5.corelib.components.ActionLink, but have not been bound.

The TML example looks like this :
<t:actionlink t:id="link1" t:mixins="exanpe/dialog">link1</t:actionlink>

With a simple type for mixin parameter (Integer or String), the same error occurs.
This behavior is only for mixins, not for components.

A simplified project that duplicates the issue has been attached : the mixin Emphasis used into Index.tml is ok in 5.2.6 and ko in 5.3.