2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.data.jaxen;
10 import static com.google.common.base.Preconditions.checkArgument;
11 import static java.util.Objects.requireNonNull;
13 import com.google.common.base.Converter;
14 import com.google.common.base.Verify;
15 import com.google.common.collect.Lists;
16 import java.util.AbstractMap.SimpleImmutableEntry;
17 import java.util.List;
18 import java.util.Optional;
19 import javax.annotation.Nonnull;
20 import javax.xml.xpath.XPathExpressionException;
21 import org.jaxen.JaxenException;
22 import org.jaxen.JaxenHandler;
23 import org.jaxen.XPathSyntaxException;
24 import org.jaxen.expr.Expr;
25 import org.jaxen.saxpath.SAXPathException;
26 import org.jaxen.saxpath.XPathReader;
27 import org.opendaylight.yangtools.yang.common.QNameModule;
28 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
29 import org.opendaylight.yangtools.yang.data.api.schema.xpath.XPathBooleanResult;
30 import org.opendaylight.yangtools.yang.data.api.schema.xpath.XPathDocument;
31 import org.opendaylight.yangtools.yang.data.api.schema.xpath.XPathExpression;
32 import org.opendaylight.yangtools.yang.data.api.schema.xpath.XPathNodesetResult;
33 import org.opendaylight.yangtools.yang.data.api.schema.xpath.XPathNumberResult;
34 import org.opendaylight.yangtools.yang.data.api.schema.xpath.XPathResult;
35 import org.opendaylight.yangtools.yang.data.api.schema.xpath.XPathStringResult;
36 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
37 import org.slf4j.Logger;
38 import org.slf4j.LoggerFactory;
40 final class JaxenXPath implements XPathExpression {
41 private static final Logger LOG = LoggerFactory.getLogger(JaxenXPath.class);
43 private final Converter<String, QNameModule> converter;
44 private final SchemaPath schemaPath;
45 private final Expr expr;
47 private JaxenXPath(final Converter<String, QNameModule> converter, final SchemaPath schemaPath,
49 this.converter = requireNonNull(converter);
50 this.schemaPath = requireNonNull(schemaPath);
51 this.expr = requireNonNull(expr);
54 static JaxenXPath create(final Converter<String, QNameModule> converter, final SchemaPath schemaPath,
55 final String xpath) throws JaxenException {
59 final XPathReader reader = new org.jaxen.saxpath.base.XPathReader();
60 final JaxenHandler handler = new JaxenHandler();
61 reader.setXPathHandler(handler);
63 parsed = handler.getXPathExpr().getRootExpr();
64 } catch (org.jaxen.saxpath.XPathSyntaxException e) {
65 throw new XPathSyntaxException(e);
66 } catch (SAXPathException e) {
67 throw new JaxenException(e);
70 LOG.debug("Compiled {} to expression {}", xpath, parsed);
72 new ExprWalker(new ExprListener() {
73 // FIXME: perform expression introspection to understand things like apex, etc.
76 return new JaxenXPath(converter, schemaPath, parsed);
80 public Optional<? extends XPathResult<?>> evaluate(@Nonnull final XPathDocument document,
81 @Nonnull final YangInstanceIdentifier path) throws XPathExpressionException {
82 checkArgument(document instanceof JaxenDocument);
84 final NormalizedNodeContextSupport contextSupport = NormalizedNodeContextSupport.create(
85 (JaxenDocument)document, converter);
87 final Object result = evaluate(contextSupport.createContext(path));
88 if (result instanceof String) {
89 return Optional.of((XPathStringResult) () -> (String) result);
90 } else if (result instanceof Number) {
91 return Optional.of((XPathNumberResult) () -> (Number) result);
92 } else if (result instanceof Boolean) {
93 return Optional.of((XPathBooleanResult) () -> (Boolean) result);
94 } else if (result == null) {
95 return Optional.empty();
98 Verify.verify(result instanceof List, "Unhandled result %s", result);
99 @SuppressWarnings("unchecked")
100 final List<NormalizedNodeContext> resultList = (List<NormalizedNodeContext>) result;
101 return Optional.of((XPathNodesetResult) () -> {
102 // XXX: Will this really work, or do we need to perform deep transformation?
103 return Lists.transform(resultList,
104 context -> new SimpleImmutableEntry<>(context.getPath(), context.getNode()));
108 private Object evaluate(final NormalizedNodeContext context) throws XPathExpressionException {
111 result = expr.evaluate(context);
112 } catch (JaxenException e) {
113 throw new XPathExpressionException(e);
116 if (result instanceof List) {
117 final List<?> list = (List<?>) result;
118 if (list.size() == 1) {
119 final Object first = list.get(0);
120 if (first instanceof String || first instanceof Number || first instanceof Boolean) {
131 public SchemaPath getEvaluationPath() {
137 public SchemaPath getApexPath() {
138 // TODO: improve this
139 return SchemaPath.ROOT;