2 * Copyright (c) 2013 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.model.util;
10 import static com.google.common.base.Preconditions.checkArgument;
11 import static com.google.common.base.Preconditions.checkState;
12 import static java.util.Objects.requireNonNull;
14 import com.google.common.annotations.Beta;
15 import com.google.common.annotations.VisibleForTesting;
16 import com.google.common.base.CharMatcher;
17 import com.google.common.base.Splitter;
18 import com.google.common.collect.Iterables;
19 import java.util.ArrayDeque;
20 import java.util.ArrayList;
21 import java.util.Arrays;
22 import java.util.Deque;
23 import java.util.HashSet;
24 import java.util.Iterator;
25 import java.util.List;
26 import java.util.Optional;
28 import java.util.regex.Pattern;
29 import java.util.stream.Collectors;
30 import org.eclipse.jdt.annotation.NonNull;
31 import org.eclipse.jdt.annotation.Nullable;
32 import org.opendaylight.yangtools.yang.common.AbstractQName;
33 import org.opendaylight.yangtools.yang.common.QName;
34 import org.opendaylight.yangtools.yang.common.QNameModule;
35 import org.opendaylight.yangtools.yang.common.UnqualifiedQName;
36 import org.opendaylight.yangtools.yang.model.api.ActionNodeContainer;
37 import org.opendaylight.yangtools.yang.model.api.CaseSchemaNode;
38 import org.opendaylight.yangtools.yang.model.api.ChoiceSchemaNode;
39 import org.opendaylight.yangtools.yang.model.api.ContainerSchemaNode;
40 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
41 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
42 import org.opendaylight.yangtools.yang.model.api.DerivableSchemaNode;
43 import org.opendaylight.yangtools.yang.model.api.GroupingDefinition;
44 import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
45 import org.opendaylight.yangtools.yang.model.api.Module;
46 import org.opendaylight.yangtools.yang.model.api.ModuleImport;
47 import org.opendaylight.yangtools.yang.model.api.NotificationDefinition;
48 import org.opendaylight.yangtools.yang.model.api.NotificationNodeContainer;
49 import org.opendaylight.yangtools.yang.model.api.OperationDefinition;
50 import org.opendaylight.yangtools.yang.model.api.PathExpression;
51 import org.opendaylight.yangtools.yang.model.api.PathExpression.DerefSteps;
52 import org.opendaylight.yangtools.yang.model.api.PathExpression.LocationPathSteps;
53 import org.opendaylight.yangtools.yang.model.api.PathExpression.Steps;
54 import org.opendaylight.yangtools.yang.model.api.RpcDefinition;
55 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
56 import org.opendaylight.yangtools.yang.model.api.SchemaNode;
57 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
58 import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
59 import org.opendaylight.yangtools.yang.model.api.TypedDataSchemaNode;
60 import org.opendaylight.yangtools.yang.model.api.type.InstanceIdentifierTypeDefinition;
61 import org.opendaylight.yangtools.yang.model.api.type.LeafrefTypeDefinition;
62 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
63 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
64 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath;
65 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.AxisStep;
66 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.QNameStep;
67 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.ResolvedQNameStep;
68 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.Step;
69 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.UnresolvedQNameStep;
70 import org.opendaylight.yangtools.yang.xpath.api.YangXPathAxis;
71 import org.slf4j.Logger;
72 import org.slf4j.LoggerFactory;
75 * The Schema Context Util contains support methods for searching through Schema Context modules for specified schema
76 * nodes via Schema Path or Revision Aware XPath. The Schema Context Util is designed as mixin, so it is not
79 public final class SchemaContextUtil {
80 private static final Logger LOG = LoggerFactory.getLogger(SchemaContextUtil.class);
81 private static final Splitter COLON_SPLITTER = Splitter.on(':');
82 private static final Splitter SLASH_SPLITTER = Splitter.on('/').omitEmptyStrings();
83 private static final CharMatcher SPACE = CharMatcher.is(' ');
85 private SchemaContextUtil() {
90 * Method attempts to find DataSchemaNode in Schema Context via specified Schema Path. The returned DataSchemaNode
91 * from method will be the node at the end of the SchemaPath. If the DataSchemaNode is not present in the Schema
92 * Context the method will return {@code null}.
95 * In case that Schema Context or Schema Path are not specified correctly (i.e. contains {@code null} values) the
96 * method will throw IllegalArgumentException.
98 * @param context Schema Context
99 * @param schemaPath Schema Path to search for
100 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
101 * @throws NullPointerException if context or schemaPath is null
103 public static SchemaNode findDataSchemaNode(final SchemaContext context, final SchemaPath schemaPath) {
104 final Iterable<QName> prefixedPath = schemaPath.getPathFromRoot();
105 if (prefixedPath == null) {
106 LOG.debug("Schema path {} has null path", schemaPath);
110 LOG.trace("Looking for path {} in context {}", schemaPath, context);
111 return findNodeInSchemaContext(context, prefixedPath);
115 * Attempt to find a DataSchemaNode based on its path from root, similar to
116 * {@link #findDataSchemaNode(SchemaContext, Module, PathExpression)} without requiring an expression.
118 * @param context Schema Context
119 * @param path Path to search for
120 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
121 * @throws NullPointerException if a any argument is null or if the path contains a null element
124 public static SchemaNode findDataSchemaNode(final SchemaContext context, final List<QName> path) {
125 return findTargetNode(context, null, YangLocationPath.absolute(
126 path.stream().map(YangXPathAxis.CHILD::asStep).collect(Collectors.toList())));
130 * Attempt to find a DataSchemaNode based on its path from root, similar to
131 * {@link #findDataSchemaNode(SchemaContext, Module, PathExpression)} without requiring an expression.
133 * @param context Schema Context
134 * @param path Path to search for
135 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
136 * @throws NullPointerException if a any argument is null or if the path contains a null element
139 public static SchemaNode findDataSchemaNode(final SchemaContext context, final QName... path) {
140 return findDataSchemaNode(context, Arrays.asList(path));
144 * Method attempts to find DataSchemaNode inside of provided Schema Context
145 * and Yang Module accordingly to Non-conditional Revision Aware XPath. The
146 * specified Module MUST be present in Schema Context otherwise the
147 * operation would fail and return <code>null</code>. <br>
148 * The Revision Aware XPath MUST be specified WITHOUT the conditional
149 * statement (i.e. without [cond]) in path, because in this state the Schema
150 * Context is completely unaware of data state and will be not able to
151 * properly resolve XPath. If the XPath contains condition the method will
152 * return IllegalArgumentException. <br>
153 * If the Revision Aware XPath is correct and desired Data Schema Node is
154 * present in Yang module or in depending module in Schema Context the
155 * method will return specified Data Schema Node, otherwise the operation
156 * will fail and method will return <code>null</code>.
162 * @param nonCondXPath
163 * Non Conditional Revision Aware XPath
164 * @return Returns Data Schema Node for specified Schema Context for given
165 * Non-conditional Revision Aware XPath, or <code>null</code> if the
166 * DataSchemaNode is not present in Schema Context.
167 * @throws NullPointerException if any of the arguments is null
168 * @deprecated Use {@link #findDataTreeSchemaNode(SchemaContext, QNameModule, YangLocationPath)} or
169 * {@link #findDataTreeSchemaNode(SchemaContext, QNameModule, PathExpression)} instead.
171 // FIXME: This entire method is ill-defined, as the resolution process depends on where the XPath is defined --
172 // notably RPCs, actions and notifications modify the data tree temporarily. See sections 6.4.1 and 9.9.2
175 // Most notably we need to understand whether the XPath is being resolved in the data tree, or as part of
176 // a notification/action/RPC, as then the SchemaContext grows tentative nodes ... which could be addressed
177 // via a derived SchemaContext (i.e. this class would have to have a
179 // SchemaContext notificationSchemaContext(SchemaContext delegate, NotificationDefinition notif)
181 // which would then be passed in to a method similar to this one. In static contexts, like MD-SAL codegen,
182 // that feels like an overkill.
184 public static SchemaNode findDataSchemaNode(final SchemaContext context, final Module module,
185 final PathExpression nonCondXPath) {
186 requireNonNull(context, "context");
187 requireNonNull(module, "module");
189 final String strXPath = nonCondXPath.getOriginalString();
190 checkArgument(strXPath.indexOf('[') == -1, "Revision Aware XPath may not contain a condition");
191 if (nonCondXPath.isAbsolute()) {
192 return findTargetNode(context, xpathToQNamePath(context, module, strXPath));
198 public static SchemaNode findDataTreeSchemaNode(final SchemaContext ctx, final QNameModule localModule,
199 final YangLocationPath absPath) {
200 checkArgument(absPath.isAbsolute(), "Unsupported relative path %s", absPath);
201 return findTargetNode(ctx, localModule, absPath);
205 public static SchemaNode findDataTreeSchemaNode(final SchemaContext ctx, final QNameModule localModule,
206 final PathExpression absPath) {
207 final Steps pathSteps = absPath.getSteps();
208 if (pathSteps instanceof LocationPathSteps) {
209 return findDataTreeSchemaNode(ctx, localModule, ((LocationPathSteps) pathSteps).getLocationPath());
212 // We would need a reference schema node and no, we do not want to use SchemaContext in its SchemaNode capacity
213 checkArgument(!(pathSteps instanceof DerefSteps), "No reference node for steps %s", pathSteps);
215 // We are missing proper API alignment, if this ever triggers
216 throw new IllegalStateException("Unsupported path " + pathSteps);
220 * Method attempts to find DataSchemaNode inside of provided Schema Context
221 * and Yang Module accordingly to Non-conditional relative Revision Aware
222 * XPath. The specified Module MUST be present in Schema Context otherwise
223 * the operation would fail and return <code>null</code>. <br>
224 * The relative Revision Aware XPath MUST be specified WITHOUT the
225 * conditional statement (i.e. without [cond]) in path, because in this
226 * state the Schema Context is completely unaware of data state and will be
227 * not able to properly resolve XPath. If the XPath contains condition the
228 * method will return IllegalArgumentException. <br>
229 * The Actual Schema Node MUST be specified correctly because from this
230 * Schema Node will search starts. If the Actual Schema Node is not correct
231 * the operation will simply fail, because it will be unable to find desired
232 * DataSchemaNode. <br>
233 * If the Revision Aware XPath doesn't have flag
234 * <code>isAbsolute == false</code> the method will throw
235 * IllegalArgumentException. <br>
236 * If the relative Revision Aware XPath is correct and desired Data Schema
237 * Node is present in Yang module or in depending module in Schema Context
238 * the method will return specified Data Schema Node, otherwise the
239 * operation will fail and method will return <code>null</code>.
245 * @param actualSchemaNode
247 * @param relativeXPath
248 * Relative Non Conditional Revision Aware XPath
249 * @return DataSchemaNode if is present in specified Schema Context for
250 * given relative Revision Aware XPath, otherwise will return
252 * @throws NullPointerException if any argument is null
254 // FIXME: This entire method is ill-defined, as the resolution process depends on where the XPath is defined --
255 // notably RPCs, actions and notifications modify the data tree temporarily. See sections 6.4.1 and 9.9.2
258 // Most notably we need to understand whether the XPath is being resolved in the data tree, or as part of
259 // a notification/action/RPC, as then the SchemaContext grows tentative nodes ... which could be addressed
260 // via a derived SchemaContext (i.e. this class would have to have a
262 // SchemaContext notificationSchemaContext(SchemaContext delegate, NotificationDefinition notif)
264 // which would then be passed in to a method similar to this one. In static contexts, like MD-SAL codegen,
265 // that feels like an overkill.
266 // FIXME: YANGTOOLS-1052: this is a static analysis util, move it to a dedicated class
267 public static SchemaNode findDataSchemaNodeForRelativeXPath(final SchemaContext context, final Module module,
268 final SchemaNode actualSchemaNode, final PathExpression relativeXPath) {
269 checkState(!relativeXPath.isAbsolute(), "Revision Aware XPath MUST be relative i.e. MUST contains ../, "
270 + "for non relative Revision Aware XPath use findDataSchemaNode method");
271 return resolveRelativeXPath(context, module, relativeXPath, actualSchemaNode);
275 * Returns parent Yang Module for specified Schema Context in which Schema
276 * Node is declared. If the Schema Node is not present in Schema Context the
277 * operation will return <code>null</code>.
279 * @param context Schema Context
280 * @param schemaNode Schema Node
281 * @return Yang Module for specified Schema Context and Schema Node, if Schema Node is NOT present, the method will
282 * return <code>null</code>
283 * @throws NullPointerException if any of the arguments is null
285 public static Module findParentModule(final SchemaContext context, final SchemaNode schemaNode) {
286 final QName qname = schemaNode.getPath().getLastComponent();
287 checkState(qname != null, "Schema Path contains invalid state of path parts. "
288 + "The Schema Path MUST contain at least ONE QName which defines namespace and Local name of path.");
289 return context.findModule(qname.getModule()).orElse(null);
292 public static SchemaNode findNodeInSchemaContext(final SchemaContext context, final Iterable<QName> path) {
293 final QName current = path.iterator().next();
295 LOG.trace("Looking up module {} in context {}", current, path);
296 final Optional<Module> module = context.findModule(current.getModule());
297 if (!module.isPresent()) {
298 LOG.debug("Module {} not found", current);
302 return findNodeInModule(module.get(), path);
306 * Returns NotificationDefinition from Schema Context.
308 * @param schema SchemaContext in which lookup should be performed.
309 * @param path Schema Path of notification
310 * @return Notification schema or null, if notification is not present in schema context.
313 public static @Nullable NotificationDefinition getNotificationSchema(final @NonNull SchemaContext schema,
314 final @NonNull SchemaPath path) {
315 requireNonNull(schema, "Schema context must not be null.");
316 requireNonNull(path, "Schema path must not be null.");
317 for (final NotificationDefinition potential : schema.getNotifications()) {
318 if (path.equals(potential.getPath())) {
326 * Returns RPC Input or Output Data container from RPC definition.
328 * @param schema SchemaContext in which lookup should be performed.
329 * @param path Schema path of RPC input/output data container
330 * @return Notification schema or null, if notification is not present in schema context.
333 public static @Nullable ContainerSchemaNode getRpcDataSchema(final @NonNull SchemaContext schema,
334 final @NonNull SchemaPath path) {
335 requireNonNull(schema, "Schema context must not be null.");
336 requireNonNull(path, "Schema path must not be null.");
337 final Iterator<QName> it = path.getPathFromRoot().iterator();
338 checkArgument(it.hasNext(), "Rpc must have QName.");
339 final QName rpcName = it.next();
340 checkArgument(it.hasNext(), "input or output must be part of path.");
341 final QName inOrOut = it.next();
342 for (final RpcDefinition potential : schema.getOperations()) {
343 if (rpcName.equals(potential.getQName())) {
344 return SchemaNodeUtils.getRpcDataSchema(potential, inOrOut);
351 * Extract the identifiers of all modules and submodules which were used to create a particular SchemaContext.
353 * @param context SchemaContext to be examined
354 * @return Set of ModuleIdentifiers.
356 public static Set<SourceIdentifier> getConstituentModuleIdentifiers(final SchemaContext context) {
357 final Set<SourceIdentifier> ret = new HashSet<>();
359 for (Module module : context.getModules()) {
360 ret.add(moduleToIdentifier(module));
362 for (Module submodule : module.getSubmodules()) {
363 ret.add(moduleToIdentifier(submodule));
370 private static SourceIdentifier moduleToIdentifier(final Module module) {
371 return RevisionSourceIdentifier.create(module.getName(), module.getRevision());
374 private static SchemaNode findNodeInModule(final Module module, final Iterable<QName> path) {
375 if (!path.iterator().hasNext()) {
376 LOG.debug("No node matching {} found in node {}", path, module);
380 final QName current = path.iterator().next();
381 LOG.trace("Looking for node {} in module {}", current, module);
383 SchemaNode foundNode = null;
384 final Iterable<QName> nextPath = nextLevel(path);
386 foundNode = module.getDataChildByName(current);
387 if (foundNode != null && nextPath.iterator().hasNext()) {
388 foundNode = findNodeIn(foundNode, nextPath);
391 if (foundNode == null) {
392 foundNode = getGroupingByName(module, current);
393 if (foundNode != null && nextPath.iterator().hasNext()) {
394 foundNode = findNodeIn(foundNode, nextPath);
398 if (foundNode == null) {
399 foundNode = getRpcByName(module, current);
400 if (foundNode != null && nextPath.iterator().hasNext()) {
401 foundNode = findNodeIn(foundNode, nextPath);
405 if (foundNode == null) {
406 foundNode = getNotificationByName(module, current);
407 if (foundNode != null && nextPath.iterator().hasNext()) {
408 foundNode = findNodeIn(foundNode, nextPath);
412 if (foundNode == null) {
413 LOG.debug("No node matching {} found in node {}", path, module);
419 private static SchemaNode findNodeIn(final SchemaNode parent, final Iterable<QName> path) {
420 if (!path.iterator().hasNext()) {
421 LOG.debug("No node matching {} found in node {}", path, parent);
425 final QName current = path.iterator().next();
426 LOG.trace("Looking for node {} in node {}", current, parent);
428 SchemaNode foundNode = null;
429 final Iterable<QName> nextPath = nextLevel(path);
431 if (parent instanceof DataNodeContainer) {
432 final DataNodeContainer parentDataNodeContainer = (DataNodeContainer) parent;
434 foundNode = parentDataNodeContainer.getDataChildByName(current);
435 if (foundNode != null && nextPath.iterator().hasNext()) {
436 foundNode = findNodeIn(foundNode, nextPath);
439 if (foundNode == null) {
440 foundNode = getGroupingByName(parentDataNodeContainer, current);
441 if (foundNode != null && nextPath.iterator().hasNext()) {
442 foundNode = findNodeIn(foundNode, nextPath);
447 if (foundNode == null && parent instanceof ActionNodeContainer) {
448 foundNode = ((ActionNodeContainer) parent).getActions().stream()
449 .filter(act -> current.equals(act.getQName())).findFirst().orElse(null);
450 if (foundNode != null && nextPath.iterator().hasNext()) {
451 foundNode = findNodeIn(foundNode, nextPath);
455 if (foundNode == null && parent instanceof NotificationNodeContainer) {
456 foundNode = ((NotificationNodeContainer) parent).getNotifications().stream()
457 .filter(notif -> current.equals(notif.getQName())).findFirst().orElse(null);
458 if (foundNode != null && nextPath.iterator().hasNext()) {
459 foundNode = findNodeIn(foundNode, nextPath);
463 if (foundNode == null && parent instanceof OperationDefinition) {
464 final OperationDefinition parentRpcDefinition = (OperationDefinition) parent;
466 if (current.getLocalName().equals("input")) {
467 foundNode = parentRpcDefinition.getInput();
468 if (foundNode != null && nextPath.iterator().hasNext()) {
469 foundNode = findNodeIn(foundNode, nextPath);
473 if (current.getLocalName().equals("output")) {
474 foundNode = parentRpcDefinition.getOutput();
475 if (foundNode != null && nextPath.iterator().hasNext()) {
476 foundNode = findNodeIn(foundNode, nextPath);
480 if (foundNode == null) {
481 foundNode = getGroupingByName(parentRpcDefinition, current);
482 if (foundNode != null && nextPath.iterator().hasNext()) {
483 foundNode = findNodeIn(foundNode, nextPath);
488 if (foundNode == null && parent instanceof ChoiceSchemaNode) {
489 foundNode = ((ChoiceSchemaNode) parent).getCaseNodeByName(current);
491 if (foundNode != null && nextPath.iterator().hasNext()) {
492 foundNode = findNodeIn(foundNode, nextPath);
495 if (foundNode == null) {
496 // fallback that tries to map into one of the child cases
497 for (final CaseSchemaNode caseNode : ((ChoiceSchemaNode) parent).getCases().values()) {
498 final DataSchemaNode maybeChild = caseNode.getDataChildByName(current);
499 if (maybeChild != null) {
500 foundNode = findNodeIn(maybeChild, nextPath);
507 if (foundNode == null) {
508 LOG.debug("No node matching {} found in node {}", path, parent);
515 private static Iterable<QName> nextLevel(final Iterable<QName> path) {
516 return Iterables.skip(path, 1);
519 private static RpcDefinition getRpcByName(final Module module, final QName name) {
520 for (final RpcDefinition rpc : module.getRpcs()) {
521 if (rpc.getQName().equals(name)) {
528 private static NotificationDefinition getNotificationByName(final Module module, final QName name) {
529 for (final NotificationDefinition notification : module.getNotifications()) {
530 if (notification.getQName().equals(name)) {
537 private static GroupingDefinition getGroupingByName(final DataNodeContainer dataNodeContainer, final QName name) {
538 for (final GroupingDefinition grouping : dataNodeContainer.getGroupings()) {
539 if (grouping.getQName().equals(name)) {
546 private static GroupingDefinition getGroupingByName(final OperationDefinition rpc, final QName name) {
547 for (final GroupingDefinition grouping : rpc.getGroupings()) {
548 if (grouping.getQName().equals(name)) {
556 * Transforms string representation of XPath to Queue of QNames. The XPath
557 * is split by "/" and for each part of XPath is assigned correct module in
559 * If Schema Context, Parent Module or XPath string contains
560 * <code>null</code> values, the method will throws IllegalArgumentException
564 * @param parentModule
568 * @return return a list of QName
570 private static List<QName> xpathToQNamePath(final SchemaContext context, final Module parentModule,
571 final String xpath) {
572 final List<QName> path = new ArrayList<>();
573 for (final String pathComponent : SLASH_SPLITTER.split(xpath)) {
574 path.add(stringPathPartToQName(context, parentModule, pathComponent));
580 * Transforms part of Prefixed Path as java String to QName. <br>
581 * If the string contains module prefix separated by ":" (i.e.
582 * mod:container) this module is provided from from Parent Module list of
583 * imports. If the Prefixed module is present in Schema Context the QName
584 * can be constructed. <br>
585 * If the Prefixed Path Part does not contains prefix the Parent's Module
586 * namespace is taken for construction of QName. <br>
588 * @param context Schema Context
589 * @param parentModule Parent Module
590 * @param prefixedPathPart Prefixed Path Part string
591 * @return QName from prefixed Path Part String.
592 * @throws NullPointerException if any arguments are null
594 private static QName stringPathPartToQName(final SchemaContext context, final Module parentModule,
595 final String prefixedPathPart) {
596 requireNonNull(context, "context");
598 if (prefixedPathPart.indexOf(':') != -1) {
599 final Iterator<String> prefixedName = COLON_SPLITTER.split(prefixedPathPart).iterator();
600 final String modulePrefix = prefixedName.next();
602 final Module module = resolveModuleForPrefix(context, parentModule, modulePrefix);
603 checkArgument(module != null, "Failed to resolve xpath: no module found for prefix %s in module %s",
604 modulePrefix, parentModule.getName());
606 return QName.create(module.getQNameModule(), prefixedName.next());
609 return QName.create(parentModule.getNamespace(), parentModule.getRevision(), prefixedPathPart);
613 * Method will attempt to resolve and provide Module reference for specified module prefix. Each Yang module could
614 * contains multiple imports which MUST be associated with corresponding module prefix. The method simply looks into
615 * module imports and returns the module that is bounded with specified prefix. If the prefix is not present
616 * in module or the prefixed module is not present in specified Schema Context, the method will return {@code null}.
618 * If String prefix is the same as prefix of the specified Module the reference to this module is returned.<br>
620 * @param context Schema Context
621 * @param module Yang Module
622 * @param prefix Module Prefix
623 * @return Module for given prefix in specified Schema Context if is present, otherwise returns <code>null</code>
624 * @throws NullPointerException if any arguments are null
626 private static Module resolveModuleForPrefix(final SchemaContext context, final Module module,
627 final String prefix) {
628 requireNonNull(context, "context");
630 if (prefix.equals(module.getPrefix())) {
634 final Set<ModuleImport> imports = module.getImports();
635 for (final ModuleImport mi : imports) {
636 if (prefix.equals(mi.getPrefix())) {
637 return context.findModule(mi.getModuleName(), mi.getRevision()).orElse(null);
644 * Resolve a relative XPath into a set of QNames.
650 * @param relativeXPath
651 * Non conditional Revision Aware Relative XPath
652 * @param actualSchemaNode
654 * @return target schema node
655 * @throws IllegalArgumentException if any arguments are null
657 private static @Nullable SchemaNode resolveRelativeXPath(final SchemaContext context, final Module module,
658 final PathExpression relativeXPath, final SchemaNode actualSchemaNode) {
659 checkState(!relativeXPath.isAbsolute(), "Revision Aware XPath MUST be relative i.e. MUST contains ../, "
660 + "for non relative Revision Aware XPath use findDataSchemaNode method");
661 checkState(actualSchemaNode.getPath() != null, "Schema Path reference for Leafref cannot be NULL");
663 final String orig = relativeXPath.getOriginalString();
664 return orig.startsWith("deref(") ? resolveDerefPath(context, module, actualSchemaNode, orig)
665 : findTargetNode(context, resolveRelativePath(context, module, actualSchemaNode, doSplitXPath(orig)));
668 private static Iterable<QName> resolveRelativePath(final SchemaContext context, final Module module,
669 final SchemaNode actualSchemaNode, final List<String> steps) {
670 // Find out how many "parent" components there are and trim them
671 final int colCount = normalizeXPath(steps);
672 final List<String> xpaths = colCount == 0 ? steps : steps.subList(colCount, steps.size());
674 final Iterable<QName> schemaNodePath = actualSchemaNode.getPath().getPathFromRoot();
675 if (Iterables.size(schemaNodePath) - colCount >= 0) {
676 return Iterables.concat(Iterables.limit(schemaNodePath, Iterables.size(schemaNodePath) - colCount),
677 Iterables.transform(xpaths, input -> stringPathPartToQName(context, module, input)));
679 return Iterables.concat(schemaNodePath,
680 Iterables.transform(xpaths, input -> stringPathPartToQName(context, module, input)));
683 private static SchemaNode resolveDerefPath(final SchemaContext context, final Module module,
684 final SchemaNode actualSchemaNode, final String xpath) {
685 final int paren = xpath.indexOf(')', 6);
686 checkArgument(paren != -1, "Cannot find matching parentheses in %s", xpath);
688 final String derefArg = SPACE.trimFrom(xpath.substring(6, paren));
689 // Look up the node which we need to reference
690 final SchemaNode derefTarget = findTargetNode(context, resolveRelativePath(context, module, actualSchemaNode,
691 doSplitXPath(derefArg)));
692 checkArgument(derefTarget != null, "Cannot find deref(%s) target node %s in context of %s", derefArg,
694 checkArgument(derefTarget instanceof TypedDataSchemaNode, "deref(%s) resolved to non-typed %s", derefArg,
697 // We have a deref() target, decide what to do about it
698 final TypeDefinition<?> targetType = ((TypedDataSchemaNode) derefTarget).getType();
699 if (targetType instanceof InstanceIdentifierTypeDefinition) {
700 // Static inference breaks down, we cannot determine where this points to
701 // FIXME: dedicated exception, users can recover from it, derive from IAE
702 throw new UnsupportedOperationException("Cannot infer instance-identifier reference " + targetType);
705 // deref() is define only for instance-identifier and leafref types, handle the latter
706 checkArgument(targetType instanceof LeafrefTypeDefinition, "Illegal target type %s", targetType);
708 final PathExpression targetPath = ((LeafrefTypeDefinition) targetType).getPathStatement();
709 LOG.debug("Derefencing path {}", targetPath);
711 final SchemaNode deref = targetPath.isAbsolute()
712 ? findTargetNode(context, actualSchemaNode.getQName().getModule(),
713 ((LocationPathSteps) targetPath.getSteps()).getLocationPath())
714 : findDataSchemaNodeForRelativeXPath(context, module, actualSchemaNode, targetPath);
716 LOG.debug("Path {} could not be derefenced", targetPath);
720 checkArgument(deref instanceof LeafSchemaNode, "Unexpected %s reference in %s", deref, targetPath);
722 final List<String> qnames = doSplitXPath(SPACE.trimLeadingFrom(xpath.substring(paren + 1)));
723 return findTargetNode(context, resolveRelativePath(context, module, deref, qnames));
726 private static @Nullable SchemaNode findTargetNode(final SchemaContext context, final QNameModule defaultModule,
727 final YangLocationPath path) {
728 final Deque<QName> ret = new ArrayDeque<>();
729 for (Step step : path.getSteps()) {
730 if (step instanceof AxisStep) {
731 // We only support parent axis steps
732 final YangXPathAxis axis = ((AxisStep) step).getAxis();
733 checkState(axis == YangXPathAxis.PARENT, "Unexpected axis %s", axis);
738 // This has to be a QNameStep
739 checkState(step instanceof QNameStep, "Unhandled step %s in %s", step, path);
741 if (step instanceof ResolvedQNameStep) {
742 qname = ((ResolvedQNameStep) step).getQName();
743 } else if (step instanceof UnresolvedQNameStep) {
744 final AbstractQName toResolve = ((UnresolvedQNameStep) step).getQName();
745 // TODO: should handle qualified QNames, too? parser should have resolved them when we get here...
746 checkState(toResolve instanceof UnqualifiedQName, "Unhandled qname %s in %s", toResolve, path);
747 qname = QName.create(defaultModule, toResolve.getLocalName());
749 throw new IllegalStateException("Unhandled step " + step);
755 return findTargetNode(context, ret);
758 private static @Nullable SchemaNode findTargetNode(final SchemaContext context, final Iterable<QName> qnamePath) {
759 // We do not have enough information about resolution context, hence cannot account for actions, RPCs
760 // and notifications. We therefore attempt to make a best estimate, but this can still fail.
761 final Optional<DataSchemaNode> pureData = context.findDataTreeChild(qnamePath);
762 return pureData.isPresent() ? pureData.get() : findNodeInSchemaContext(context, qnamePath);
766 static int normalizeXPath(final List<String> xpath) {
767 LOG.trace("Normalize {}", xpath);
769 // We need to make multiple passes here, as the leading XPaths as we can have "../abc/../../def", which really
772 // Next up: count leading ".." components
773 int leadingParents = 0;
775 if (leadingParents == xpath.size()) {
776 return leadingParents;
778 if (!"..".equals(xpath.get(leadingParents))) {
785 // Now let's see if there there is a '..' in the rest
786 final int dots = findDots(xpath, leadingParents + 1);
788 return leadingParents;
791 xpath.remove(dots - 1);
792 xpath.remove(dots - 1);
793 LOG.trace("Next iteration {}", xpath);
797 private static int findDots(final List<String> xpath, final int startIndex) {
798 for (int i = startIndex; i < xpath.size(); ++i) {
799 if ("..".equals(xpath.get(i))) {
807 private static List<String> doSplitXPath(final String xpath) {
808 return SLASH_SPLITTER.splitToList(xpath);
812 * Extracts the base type of node on which schema node points to. If target node is again of type
813 * LeafrefTypeDefinition, methods will be call recursively until it reach concrete type definition.
815 * @param typeDefinition
816 * type of node which will be extracted
817 * @param schemaContext
821 * @return recursively found type definition this leafref is pointing to or null if the xpath is incorrect (null
822 * is there to preserve backwards compatibility)
824 public static TypeDefinition<?> getBaseTypeForLeafRef(final LeafrefTypeDefinition typeDefinition,
825 final SchemaContext schemaContext, final SchemaNode schema) {
826 PathExpression pathStatement = typeDefinition.getPathStatement();
827 pathStatement = new PathExpressionImpl(stripConditionsFromXPathString(pathStatement),
828 pathStatement.isAbsolute());
830 final DataSchemaNode dataSchemaNode;
831 if (pathStatement.isAbsolute()) {
832 SchemaNode baseSchema = schema;
833 while (baseSchema instanceof DerivableSchemaNode) {
834 final Optional<? extends SchemaNode> basePotential = ((DerivableSchemaNode) baseSchema).getOriginal();
835 if (basePotential.isPresent()) {
836 baseSchema = basePotential.get();
842 Module parentModule = findParentModuleOfReferencingType(schemaContext, baseSchema);
843 dataSchemaNode = (DataSchemaNode) findDataSchemaNode(schemaContext, parentModule, pathStatement);
845 Module parentModule = findParentModule(schemaContext, schema);
846 dataSchemaNode = (DataSchemaNode) findDataSchemaNodeForRelativeXPath(schemaContext, parentModule, schema,
850 // FIXME this is just to preserve backwards compatibility since yangtools do not mind wrong leafref xpaths
851 // and current expected behaviour for such cases is to just use pure string
852 // This should throw an exception about incorrect XPath in leafref
853 if (dataSchemaNode == null) {
857 final TypeDefinition<?> targetTypeDefinition = typeDefinition(dataSchemaNode);
859 if (targetTypeDefinition instanceof LeafrefTypeDefinition) {
860 return getBaseTypeForLeafRef((LeafrefTypeDefinition) targetTypeDefinition, schemaContext, dataSchemaNode);
863 return targetTypeDefinition;
867 * Returns base type for {@code typeDefinition} which belongs to module specified via {@code qname}. This handle
868 * the case when leafref type isn't specified as type substatement of leaf or leaf-list but is defined in other
869 * module as typedef which is then imported to referenced module.
872 * Because {@code typeDefinition} is definied via typedef statement, only absolute path is meaningful.
874 public static TypeDefinition<?> getBaseTypeForLeafRef(final LeafrefTypeDefinition typeDefinition,
875 final SchemaContext schemaContext, final QName qname) {
876 final PathExpression pathStatement = typeDefinition.getPathStatement();
877 if (!pathStatement.isAbsolute()) {
881 final PathExpression strippedPathStatement = new PathExpressionImpl(
882 stripConditionsFromXPathString(pathStatement), true);
884 final Optional<Module> parentModule = schemaContext.findModule(qname.getModule());
885 checkArgument(parentModule.isPresent(), "Failed to find parent module for %s", qname);
887 final DataSchemaNode dataSchemaNode = (DataSchemaNode) findDataSchemaNode(schemaContext, parentModule.get(),
888 strippedPathStatement);
889 final TypeDefinition<?> targetTypeDefinition = typeDefinition(dataSchemaNode);
890 if (targetTypeDefinition instanceof LeafrefTypeDefinition) {
891 return getBaseTypeForLeafRef((LeafrefTypeDefinition) targetTypeDefinition, schemaContext, dataSchemaNode);
894 return targetTypeDefinition;
897 private static Module findParentModuleOfReferencingType(final SchemaContext schemaContext,
898 final SchemaNode schemaNode) {
899 checkArgument(schemaContext != null, "Schema Context reference cannot be NULL!");
900 checkArgument(schemaNode instanceof TypedDataSchemaNode, "Unsupported node %s", schemaNode);
902 TypeDefinition<?> nodeType = ((TypedDataSchemaNode) schemaNode).getType();
903 if (nodeType.getBaseType() != null) {
904 while (nodeType.getBaseType() != null) {
905 nodeType = nodeType.getBaseType();
908 return schemaContext.findModule(nodeType.getQName().getModule()).orElse(null);
911 return findParentModule(schemaContext, schemaNode);
914 private static final Pattern STRIP_PATTERN = Pattern.compile("\\[[^\\[\\]]*\\]");
917 * Removes conditions from xPath pointed to target node.
919 * @param pathStatement
920 * xPath to target node
921 * @return string representation of xPath without conditions
924 static String stripConditionsFromXPathString(final PathExpression pathStatement) {
925 return STRIP_PATTERN.matcher(pathStatement.getOriginalString()).replaceAll("");
929 * Gets the base type of DataSchemaNode value.
932 * a node representing DataSchemaNode
933 * @return concrete type definition of node value
935 private static TypeDefinition<?> typeDefinition(final DataSchemaNode node) {
936 checkArgument(node instanceof TypedDataSchemaNode, "Unhandled parameter type %s", node);
938 TypeDefinition<?> current = ((TypedDataSchemaNode) node).getType();
939 // TODO: don't we have a utility for this?
940 TypeDefinition<?> base = current.getBaseType();
941 while (base != null) {
943 base = current.getBaseType();