[TAPESTRY-2476] Unhelpful exception messages when a null value is bound to a required parameter

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 5.0.11
• Fix Version/s: 5.0.14
• Component/s: Core Components
• Environment: Windows XP Service Pack 2, FireFox 2.0.0.14, Eclipse 3.3.2, Maven 2.0.9, Run-Jetty-Run, Java 1.6.0_3
• Assignee: Howard Lewis Ship
• Reporter: Daniel
• Created: 24/Jun/08 15:37
• Updated: 24/Jun/08 22:42
• Resolved: 24/Jun/08 22:42

Description

Example exception:
Render queue error in SetupRender[MainPage:tilesetsearch.palette]:
org.apache.tapestry.ioc.internal.util.TapestryException

Example tml line:
<t:palette t:model="keywordModel" t:selected="selectedKeywordIds" t:encoder="longEncoder" t:size="5"/>

Example stack trace: java.lang.NullPointerException

• org.apache.tapestry.corelib.components...
  Palette.setupRender(Palette.java:379)
• Palette.setupRender(Palette.java)
• org.apache.tapestry.internal.structure...
  ComponentPageElementImpl$13$1.run(ComponentPageElementImpl.java:478)
• ComponentPageElementImpl.invoke(ComponentPageElementImpl.java:880)
• ComponentPageElementImpl.access$100(ComponentPageElementImpl.java:54)
• ComponentPageElementImpl$13.render(ComponentPageElementImpl.java:482)
• org.apache.tapestry.internal.services...
  RenderQueueImpl.run(RenderQueueImpl.java:63)
• PageRenderQueueImpl.render(PageRenderQueueImpl.java:84)

This constitutes one example where the t:selected parameter was null. Later I got the same exception message with a different stack trace when the same parameter was null, but for a different reason.

Perhaps required parameters should not only be bound, but also null checked.