/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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 org.apache.cocoon.components.treeprocessor.variables;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.components.treeprocessor.InvokeContext;
import org.apache.cocoon.sitemap.PatternException;
import org.apache.cocoon.sitemap.SitemapParameters;
import org.apache.cocoon.util.location.Locatable;
import org.apache.cocoon.util.location.Location;
/**
* Utility class for handling {...} pattern substitutions in sitemap statements.
*
* @author <a href="mailto:sylvain@apache.org">Sylvain Wallez</a>
* @version CVS $Id: VariableResolver.java 232400 2005-08-12 22:14:26Z sylvain $
*/
public abstract class VariableResolver {
public static final Map EMPTY_MAP = Collections.unmodifiableMap(new java.util.HashMap(0));
protected final String originalExpr;
protected VariableResolver(String expr) {
this.originalExpr = expr;
}
public final String toString() {
return this.originalExpr;
}
/**
* Compare two VariableResolvers
*/
public boolean equals(Object object) {
if (object instanceof VariableResolver) {
VariableResolver other = (VariableResolver)object;
return (this.originalExpr == null && other.originalExpr == null) ||
(this.originalExpr.equals(other.originalExpr));
} else {
return false;
}
}
/**
* generate HashCode
* needed to determine uniqueness within hashtables
*/
public int hashCode() {
return this.originalExpr == null ? 0 : this.originalExpr.hashCode();
}
/**
* Resolve all {...} patterns using the values given in the object model.
*/
public String resolve(Map objectModel) throws PatternException {
return resolve(null, objectModel);
}
/**
* Resolve all {...} patterns using the values given in the list of maps and the object model.
*/
public abstract String resolve(InvokeContext context, Map objectModel) throws PatternException;
/**
* Build a <code>Parameters</code> object from a Map of named <code>VariableResolver</code>s and
* a list of Maps used for resolution.
*
* @return a fully resolved <code>Parameters</code>.
*/
public static Parameters buildParameters(Map expressions, InvokeContext context, Map objectModel) throws PatternException {
Location location;
if (expressions instanceof Locatable) {
location = ((Locatable)expressions).getLocation();
} else {
location = Location.UNKNOWN;
}
if (expressions == null || expressions.size() == 0 && location.equals(Location.UNKNOWN)) {
return Parameters.EMPTY_PARAMETERS;
}
SitemapParameters result = new SitemapParameters(location);
Iterator iter = expressions.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry entry = (Map.Entry)iter.next();
result.setParameter(
((VariableResolver)entry.getKey()).resolve(context, objectModel),
((VariableResolver)entry.getValue()).resolve(context, objectModel)
);
}
return result;
}
/**
* Build a <code>Map</code> from a Map of named <code>ListOfMapResolver</code>s and
* a list of Maps used for resolution.
*
* @return a fully resolved <code>Map</code>.
*/
public static Map buildMap(Map expressions, InvokeContext context, Map objectModel) throws PatternException {
int size;
if (expressions == null || (size = expressions.size()) == 0) {
return EMPTY_MAP;
}
Map result;
if ( expressions instanceof Locatable ) {
result = new SitemapParameters.LocatedHashMap(((Locatable)expressions).getLocation(), size);
} else {
result = new HashMap(size);
}
Iterator iter = expressions.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry entry = (Map.Entry)iter.next();
result.put(
((VariableResolver)entry.getKey()).resolve(context, objectModel),
((VariableResolver)entry.getValue()).resolve(context, objectModel)
);
}
return result;
}
// /**
// * Release a <code>Map</code> of expressions.
// */
// public static void release(Map expressions) {
// Iterator iter = expressions.entrySet().iterator();
// while (iter.hasNext()) {
// Map.Entry entry = (Map.Entry)iter.next();
// ((VariableResolver)entry.getKey()).release();
// ((VariableResolver)entry.getValue()).release();
// }
// }
}