- /*
- * Copyright 2002,2004 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.jexl.parser;
-
- import org.apache.commons.jexl.JexlContext;
-
- /**
- * reference - any variable expression
- *
- * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
- * @version $Id: ASTReference.java,v 1.4 2004/09/01 00:35:38 dion Exp $
- */
- public class ASTReference extends SimpleNode
- {
- SimpleNode root;
-
- public ASTReference(int id)
- {
- super(id);
- }
-
- public ASTReference(Parser p, int id)
- {
- super(p, id);
- }
-
-
- /** Accept the visitor. **/
- public Object jjtAccept(ParserVisitor visitor, Object data)
- {
- return visitor.visit(this, data);
- }
-
- public Object value(JexlContext jc)
- throws Exception
- {
- return execute(null,jc);
- }
-
- public void jjtClose()
- {
- root = (SimpleNode) jjtGetChild(0);
- }
-
- public Object execute(Object obj, JexlContext jc)
- throws Exception
- {
- Object o = root.value(jc);
-
- /*
- * ignore the first child - it's our identifier
- */
- for(int i=1; i<jjtGetNumChildren(); i++)
- {
- o = ( (SimpleNode) jjtGetChild(i)).execute(o,jc);
-
- // check for a variable in the context named
- // child0.child1.child2 etc
- if(o == null) {
- String varName = getIdentifierToDepth(i);
- o = jc.getVars().get(varName);
- }
- }
-
- return o;
- }
-
- /**
- * This method returns a variable from this identifier and
- * it's children. For an expression like 'a.b.c', a is child
- * zero, b is child 1 and c is child 2.
- *
- * @param i the depth of the child nodes to go to
- * @return the a dotted variable from this identifier and it's
- * child nodes.
- */
- private String getIdentifierToDepth(int i) {
- StringBuffer varName = new StringBuffer();
- for (int j = 0; j <=i; j++) {
- SimpleNode node = (SimpleNode) jjtGetChild(j);
- if (node instanceof ASTIdentifier) {
- varName.append(((ASTIdentifier)node).getIdentifierString());
- if (j != i) varName.append('.');
- }
- }
- return varName.toString();
- }
-
- public String getRootString()
- throws Exception
- {
- if ( root instanceof ASTIdentifier)
- return ((ASTIdentifier) root).getIdentifierString();
-
- if (root instanceof ASTArrayAccess)
- return ((ASTArrayAccess) root).getIdentifierString();
-
- throw new Exception("programmer error : ASTReference : root not known"
- + root );
- }
- }