- /*
- * 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.commons.jxpath.ri.compiler;
-
- import java.util.Arrays;
-
- import org.apache.commons.jxpath.Function;
- import org.apache.commons.jxpath.JXPathException;
- import org.apache.commons.jxpath.ri.EvalContext;
- import org.apache.commons.jxpath.ri.QName;
-
- /**
- * Represents an element of the parse tree representing an extension function
- * call.
- *
- * @author Dmitri Plotnikov
- * @version $Revision: 1.13 $ $Date: 2004/03/25 05:42:01 $
- */
- public class ExtensionFunction extends Operation {
-
- private QName functionName;
-
- public ExtensionFunction(QName functionName, Expression args[]) {
- super(args);
- this.functionName = functionName;
- }
-
- public QName getFunctionName() {
- return functionName;
- }
-
- /**
- * An extension function gets the current context, therefore it MAY be
- * context dependent.
- */
- public boolean computeContextDependent() {
- return true;
- }
-
- public String toString() {
- StringBuffer buffer = new StringBuffer();
- buffer.append(functionName);
- buffer.append('(');
- Expression args[] = getArguments();
- if (args != null) {
- for (int i = 0; i < args.length; i++) {
- if (i > 0) {
- buffer.append(", ");
- }
- buffer.append(args[i]);
- }
- }
- buffer.append(')');
- return buffer.toString();
- }
-
- public Object compute(EvalContext context) {
- return computeValue(context);
- }
-
- public Object computeValue(EvalContext context) {
- Object[] parameters = null;
- if (args != null) {
- parameters = new Object[args.length];
- for (int i = 0; i < args.length; i++) {
- parameters[i] = convert(args[i].compute(context));
- }
- }
-
- Function function =
- context.getRootContext().getFunction(functionName, parameters);
- if (function == null) {
- throw new JXPathException(
- "No such function: "
- + functionName
- + Arrays.asList(parameters));
- }
-
- return function.invoke(context, parameters);
- }
-
- private Object convert(Object object) {
- if (object instanceof EvalContext) {
- return ((EvalContext) object).getValue();
- }
- return object;
- }
- }