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.parser.spi.meta;
10 import com.google.common.annotations.Beta;
11 import java.util.Optional;
12 import org.eclipse.jdt.annotation.NonNull;
13 import org.eclipse.jdt.annotation.Nullable;
14 import org.opendaylight.yangtools.yang.common.QName;
15 import org.opendaylight.yangtools.yang.common.QNameModule;
16 import org.opendaylight.yangtools.yang.model.api.meta.ArgumentDefinition;
17 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
18 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
19 import org.opendaylight.yangtools.yang.model.api.meta.StatementDefinition;
20 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext.Mutable;
21 import org.opendaylight.yangtools.yang.parser.spi.source.SourceException;
24 * Support for processing concrete YANG statement.
27 * This interface is intended to be implemented by developers, which want to introduce support of statement to parser.
28 * Consider subclassing {@link AbstractStatementSupport} for easier implementation of this interface.
30 * @param <A> Argument type
31 * @param <D> Declared Statement representation
32 * @param <E> Effective Statement representation
34 public interface StatementSupport<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>>
35 extends StatementDefinition, StatementFactory<A, D, E> {
37 * Returns public statement definition, which will be present in built statements.
40 * Public statement definition may be used to provide different implementation of statement definition,
41 * which will not retain any build specific data or context.
43 * @return public statement definition, which will be present in built statements.
45 @NonNull StatementDefinition getPublicView();
48 * Parses textual representation of argument in object representation.
50 * @param ctx Context, which may be used to access source-specific namespaces required for parsing.
51 * @param value String representation of value, as was present in text source.
52 * @return Parsed value
53 * @throws SourceException when an inconsistency is detected.
55 A parseArgumentValue(StmtContext<?, ?, ?> ctx, String value);
58 * Adapts the argument value to match a new module.
60 * @param ctx Context, which may be used to access source-specific namespaces required for parsing.
61 * @param targetModule Target module, may not be null.
62 * @return Adapted argument value. The default implementation returns original value stored in context.
64 default A adaptArgumentValue(final StmtContext<A, D, E> ctx, final QNameModule targetModule) {
65 return ctx.argument();
69 * Invoked when a statement supported by this instance is added to build context. This allows implementations
70 * of this interface to start tracking the statement and perform any modifications to the build context hierarchy,
71 * accessible via {@link StmtContext#getParentContext()}. One such use is populating the parent's namespaces to
72 * allow it to locate this child statement.
74 * @param stmt Context of added statement. No substatements are available.
76 void onStatementAdded(StmtContext.Mutable<A, D, E> stmt);
79 * Invoked when statement is closed during {@link ModelProcessingPhase#SOURCE_PRE_LINKAGE} phase, only substatements
80 * from this and previous phase are available.
83 * Implementation may use method to perform actions on this event or register modification action using
84 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
86 * @param stmt Context of added statement.
88 void onPreLinkageDeclared(StmtContext.Mutable<A, D, E> stmt);
91 * Invoked when statement is closed during {@link ModelProcessingPhase#SOURCE_LINKAGE} phase, only substatements
92 * from this and previous phase are available.
95 * Implementation may use method to perform actions on this event or register modification action using
96 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
98 * @param stmt Context of added statement.
99 * @throws SourceException when an inconsistency is detected.
101 void onLinkageDeclared(StmtContext.Mutable<A, D, E> stmt);
104 * Invoked when statement is closed during {@link ModelProcessingPhase#STATEMENT_DEFINITION} phase,
105 * only substatements from this phase are available.
108 * Implementation may use method to perform actions on this event or register modification action using
109 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
111 * @param stmt Context of added statement. Argument and statement parent is accessible.
112 * @throws SourceException when an inconsistency is detected.
114 void onStatementDefinitionDeclared(StmtContext.Mutable<A, D, E> stmt);
117 * Invoked when statement is closed during {@link ModelProcessingPhase#FULL_DECLARATION} phase,
118 * only substatements from this phase are available.
121 * Implementation may use method to perform actions on this event or register modification action using
122 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
124 * @param stmt Context of added statement. Argument and statement parent is accessible.
125 * @throws SourceException when an inconsistency is detected.
127 void onFullDefinitionDeclared(StmtContext.Mutable<A, D, E> stmt);
130 * Returns true if this support has argument specific supports.
132 boolean hasArgumentSpecificSupports();
135 * If this support has argument specific supports, the method returns support specific for given argument
136 * (e.g. type statement support need to be specialized based on its argument), otherwise returns null.
138 * @param argument argument of statement
139 * @return statement support specific for supplied argument or null
141 @Nullable StatementSupport<?, ?, ?> getSupportSpecificForArgument(String argument);
144 * Determine reactor copy behavior of a statement instance. Statement support classes are required to determine
145 * their operations with regard to their statements being replicated into different contexts, so that
146 * {@link Mutable} instances are not created when it is evident they are superfluous.
149 * The copy operation has three intrinsic parts:
151 * <li>target {@code parent}, i.e. new parent statement for the copy. This determines things like default value
152 * of the {@code config} statement and similar</li>
153 * <li>copy operation type</li>
154 * <li>{@code target module}, which defines the default namespace for the statement copy. This might not be always
155 * present, in which case the namespace is retained from the source. As an example, {@code uses} changes
156 * the default namespace to parent's namespace, whereas {@code augment} does not.</li>
159 * @param stmt Context of statement to be copied statement
160 * @param parent Parent statement context
161 * @param copyType Type of copy being performed
162 * @param targetModule Target module, if present
163 * @return Policy that needs to be applied to the copy operation of this statement.
165 default @NonNull CopyPolicy applyCopyPolicy(final Mutable<?, ?, ?> stmt, final Mutable<?, ?, ?> parent,
166 final CopyType copyType, @Nullable final QNameModule targetModule) {
167 // Most of statement supports will just want to copy the statement
168 // FIXME: YANGTOOLS-694: that is not strictly true. Subclasses of this should indicate if they are themselves
170 // 1) if they are not and cannot be targeted by inference, and all their current
171 // substatements are also non-sensitive, we want to return the same context.
172 // 2) if they are not and their current substatements are sensitive, we want to copy
173 // as a lazily-instantiated interceptor to let it deal with substatements when needed
174 // (YANGTOOLS-1067 prerequisite)
175 // 3) otherwise perform this eager copy
176 // return Optional.of(parent.childCopyOf(stmt, copyType, targetModule));
177 return CopyPolicy.DECLARED_COPY;
181 * Given a raw string representation of an argument, try to use a shared representation.
183 * @param rawArgument Argument string
184 * @return A potentially-shard instance
186 default String internArgument(final String rawArgument) {
191 * Returns unknown statement form of a regular YANG statement supplied as a parameter to the method.
193 * @param yangStmtDef statement definition of a regular YANG statement
194 * @return Optional of unknown statement form of a regular YANG statement or empty() if it is not supported by this
197 default Optional<StatementSupport<?, ?, ?>> getUnknownStatementDefinitionOf(final StatementDefinition yangStmtDef) {
198 return Optional.empty();
202 * Returns true if this statement support and all its substatements ignore if-feature statements (e.g. yang-data
203 * extension defined in <a href="https://tools.ietf.org/html/rfc8040#section-8">RFC 8040</a>). Default
204 * implementation returns false.
206 * @return true if this statement support ignores if-feature statements,
210 default boolean isIgnoringIfFeatures() {
215 * Returns true if this statement support and all its substatements ignore config statements (e.g. yang-data
216 * extension defined in <a href="https://tools.ietf.org/html/rfc8040#section-8">RFC 8040</a>). Default
217 * implementation returns false.
219 * @return true if this statement support ignores config statements,
223 default boolean isIgnoringConfig() {
228 default QName getStatementName() {
229 return getPublicView().getStatementName();
233 default @NonNull Optional<ArgumentDefinition> getArgumentDefinition() {
234 return getPublicView().getArgumentDefinition();
238 default Class<? extends DeclaredStatement<?>> getDeclaredRepresentationClass() {
239 return getPublicView().getDeclaredRepresentationClass();
243 default Class<? extends EffectiveStatement<?,?>> getEffectiveRepresentationClass() {
244 return getPublicView().getEffectiveRepresentationClass();
248 * Statement context copy policy, indicating how should reactor handle statement copy operations. Every statement
249 * copied by the reactor is subject to policy check done by
250 * {@link StatementSupport#applyCopyPolicy(Mutable, Mutable, CopyType, QNameModule)}.
255 * Reuse the source statement context in the new place, as it cannot be affected by any further operations. This
256 * implies that the semantics of the effective statement are not affected by any of its substatements. Each
257 * of the substatements is free to make its own policy.
260 * This policy is typically used by static constant statements such as {@code description} or {@code length},
261 * where the baseline RFC7950 does not allow any impact. A {@code description} could hold an extension statement
262 * in which case this interaction would come into play. Normal YANG will see empty substatements, so the reactor
263 * will be free to complete reuse the context.
266 * In case any substatement is of stronger policy, it is up to the reactor to handle correct handling of
267 * resulting subobjects.
269 // TODO: does this mean source must have transitioned to ModelProcessingPhase.EFFECTIVE_MODEL?
272 * Create a copy sharing declared instance, but otherwise having a separate disconnected lifecycle.
274 // TODO: will the copy transition to ModelProcessingPhase.FULL_DECLARATION or which phase?
277 * Reject any attempt to copy this statement. This is useful for statements that are defined as top-level
278 * constructs, such as {@code contact}, {@code deviation} and similar.
282 * Ignore this statement's existence for the purposes of the new place -- it is not impacted. This guidance
283 * is left here for completeness, as it can have justifiable uses (but I can't think of any). Any substatements
284 * need to be ignored, too.