| Summary: | Wrong getValueReference behaviour with Facelets parameter expressions | ||
|---|---|---|---|
| Product: | Tomcat 7 | Reporter: | JustasR <justas.ratkevicius> |
| Component: | Servlet & JSP API | Assignee: | Tomcat Developers Mailing List <dev> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | ||
| Priority: | P2 | ||
| Version: | 7.0.22 | ||
| Target Milestone: | --- | ||
| Hardware: | PC | ||
| OS: | All | ||
| Attachments: | Test case for ValueReference returning null | ||
Can you provide small simple web application that demonstrates the problem? That SimpleNode that you operate on - what is its exact className? (Which one of subclasses of SimpleNode that is?) Created attachment 28130 [details]
Test case for ValueReference returning null
I use SystemEventListener event javax.faces.event.PreRenderComponentEvent to intercept component render process ant try to get component ValueExpression and ValueReference from it (class TestSystemEventListener).
I use Facelets custom components with taglib file (not composite component).
Returned ValueReference is always null.
Null is returned from node AstIdentifier (super class SimpleNode)
I print returned ValueReference value to console.
I think I have this fixed but I'd like to confirm this with the test case. Please provide some details (the URL being the most important) of how this test case is meant to be used. Fixed based on the spec language for getValueReference() |
ValueExpression method getValueReference should return base object and property. But it returns null if ValueExpression is Facelets parameter. Example: someVar = #{concreteObject.property} ValueExpression for #{someVar} return null from method getValueReference (guess because it is simple expression #{someVar}), but logicaly it should return parent expressions ValueReference (need hierachical ValueReference lookup). I made workaround with Java Reflect API in my code and it illustrates problem: ELContext elContext = FacesContext.getCurrentInstance().getELContext(); ValueReference reference = exp.getValueReference(elContext); if (reference == null && exp instanceof TagValueExpressionUEL) { ValueExpressionImpl origExp = (ValueExpressionImpl) ((TagValueExpressionUEL) exp).getWrapped(); // TODO: JR: find better way to get base and property. ! Code is not portable because uses Tomcat EL implementation details. ! Field field = ReflectionUtils.findField(origExp.getClass(), EL_IMPL_VAR_PROPERTY); field.setAccessible(true); VariableMapper varMapper = (VariableMapper) ReflectionUtils.getField(field, origExp); field = ReflectionUtils.findField(origExp.getClass(), EL_IMPL_NODE_PROPERTY); field.setAccessible(true); SimpleNode node = (SimpleNode) ReflectionUtils.getField(field, origExp); if (varMapper != null && node != null) { ValueExpression parentExp = varMapper.resolveVariable(node.getImage()); if (parentExp != null) { try { reference = parentExp.getValueReference(elContext); if (reference == null) { reference = getValueReference(parentExp); } } catch (PropertyNotFoundException e) { LOG.warn("Property not found: " + e.getMessage()); } } } }