/* Copyright 2008 Tim Fennell
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.sourceforge.stripes.tag;
import javax.servlet.jsp.tagext.TagExtraInfo;
import javax.servlet.jsp.tagext.VariableInfo;
import javax.servlet.jsp.tagext.TagData;
import javax.servlet.jsp.tagext.ValidationMessage;
import java.util.Collection;
import java.util.ArrayList;
/**
* Validates that the mutually exclusive attribute pairs of the tag are provided correctly
* and attempts to provide type information to the container for the bean assigned
* to the variable named by the {@code var} or {@code id} attribute. The latter can only be done
* when the {@code beanclass} attribute is used instead of the {@code binding} attribute
* because runtime information is needed to translate {@code binding} into a class name.
*
* @author tfenne
* @since Stripes 1.5
*/
public class UseActionBeanTagExtraInfo extends TagExtraInfo {
private static final VariableInfo[] NO_INFO = new VariableInfo[0];
/**
* Attempts to return type information so that the container can create a
* named variable for the action bean.
*/
@Override public VariableInfo[] getVariableInfo(final TagData tag) {
// We can only provide the type of 'var' if beanclass was used because
// if binding was used we need runtime information!
Object beanclass = tag.getAttribute("beanclass");
// Turns out beanclass="${...}" does NOT return TagData.REQUEST_TIME_VALUE; only beanclass="<%= ... %>".
if (beanclass != null && !beanclass.equals(TagData.REQUEST_TIME_VALUE)) {
String var = tag.getAttributeString("var");
if (var == null) var = tag.getAttributeString("id");
// Make sure we have the class name, not the class
if (beanclass instanceof Class) beanclass = ((Class<?>) beanclass).getName();
// Return the variable info
if (beanclass instanceof String) {
String string = (String) beanclass;
if (!string.startsWith("${")) {
return new VariableInfo[] { new VariableInfo(var, string, true, VariableInfo.AT_BEGIN) };
}
}
}
return NO_INFO;
}
/**
* Checks to ensure that where the tag supports providing one of two attributes
* that one and only one is provided.
*/
@Override public ValidationMessage[] validate(final TagData tag) {
Collection<ValidationMessage> errors = new ArrayList<ValidationMessage>();
Object beanclass = tag.getAttribute("beanclass");
String binding = tag.getAttributeString("binding");
if (!(beanclass != null ^ binding != null)) {
errors.add(new ValidationMessage(tag.getId(), "Exactly one of 'beanclass' or 'binding' must be supplied."));
}
String var = tag.getAttributeString("var");
String id = tag.getAttributeString("id");
if (!(var != null ^ id != null)) {
errors.add(new ValidationMessage(tag.getId(), "Exactly one of 'var' or 'id' must be supplied."));
}
return errors.toArray(new ValidationMessage[errors.size()]);
}
}