[richfaces-issues] [JBoss JIRA] (RF-12353) Incorrect documentation/taglib on <a4j:param>

Incorrect documentation/taglib on <a4j:param> --------------------------------------------- Key: RF-12353 URL: https://issues.jboss.org/browse/RF-12353 Project: RichFaces Issue Type: Bug Security Level: Public(Everyone can see) Components: component-a4j-core, doc Affects Versions: 4.2.0.Final, 4.2.2.Final Environment: no matter Reporter: Alexander Kiselyov Priority: Trivial Labels: String, a4j:param, assignTo, converter Fix For: 4.3.0.Milestone2 Technical background (RichFaces developers can easy skip it): ---- <a4j:param> performs setting of its value into an expression specified in "assignTo" attribute. As this component is set as Action listener for ActionSource parent - org.richfaces.component.AbstractParameter.processAction(ActionEvent) is called. This method directly retrieves request parameter with this parameter's name/clientId: String requestValue = context.getExternalContext().getRequestParameterMap().get(getName()); and then, if converter's not found, sets it as a value of an expression, specified in "assignTo": {code} if (requestValue != null) { Class<?> type = updateBinding.getType(elContext); Converter converter = createConverter(context, type); ... } if (null != convertedValue) { updateBinding.setValue(elContext, convertedValue); } {code} When our expression value has reifiable type, for which JSF (or app developer) has registered a converter (for instance - Boolean) - all's peachy keen. But when developer uses, e.g., Map - expression's type (got in updateBinding.getType(ELContext)) is Object, and we're starting to receive strings in Map, which is probably parameterized with anything. Also this situation applies to "non-standard" reference types (user-declared JavaBean, for instance). {code} org.richfaces.view.facelets.html.ParameterHandler: org.richfaces.view.facelets.html.ParameterHandler.ActionParamMetaRule.applyRule(String, TagAttribute, MetadataTarget): ... else if ("converter".equals(name)) { if (attribute.isLiteral()) { return new LiteralConverterMetadata(attribute.getValue()); } else { return new DynamicConverterMetadata(attribute); } } ... {code} I.e. <a4j:param> tag handler designed to accept "converter" attribute, which can appropriately convert value, passed from client. ---- [a4j:param VDL Doc|http://docs.jboss.org/richfaces/4.2.X/4.2.2.Final/vdldoc/a4j/param.html] has no mention of it, and value/assignTo attributes type specified as "java.lang.Object". a4j.taglib.xml has no mention of it, so developers have no chance to discover it, e.g., through the content assist, [Rich Component Reference|http://docs.jboss.org/richfaces/4.2.X/4.2.2.Final/Component_Ref...] has only two sentences about it, which are *very easy to miss*. Also, [RichFaces Showcase|http://showcase.richfaces.org/richfaces/component-sample.jsf?dem...] contains no example, which uses "converter" attribute.