/*
* Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.yang.data.impl.codec.xml;
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.base.Verify;
import java.net.URI;
import java.util.Map.Entry;
import javax.annotation.Nonnull;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.common.QNameModule;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.impl.codec.TypeDefinitionAwareCodec;
import org.opendaylight.yangtools.yang.model.api.LeafListSchemaNode;
import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import org.opendaylight.yangtools.yang.model.api.SchemaNode;
import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.IdentityrefTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.InstanceIdentifierTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.LeafrefTypeDefinition;
import org.opendaylight.yangtools.yang.model.util.SchemaContextUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Utility class for bridging JAXP Stream and YANG Data APIs. Note that the definition of this class
* by no means final and subject to change as more functionality is centralized here.
*/
@Beta
public final class XmlStreamUtils {
private static final Logger LOG = LoggerFactory.getLogger(XmlStreamUtils.class);
private final XmlCodecProvider codecProvider;
private final Optional<SchemaContext> schemaContext;
private XmlStreamUtils(final XmlCodecProvider codecProvider, final SchemaContext schemaContext) {
this.codecProvider = Preconditions.checkNotNull(codecProvider);
this.schemaContext = Optional.fromNullable(schemaContext);
}
/**
* Create a new instance encapsulating a particular codec provider.
*
* @param codecProvider XML codec provider
* @return A new instance
*/
public static XmlStreamUtils create(final XmlCodecProvider codecProvider) {
return new XmlStreamUtils(codecProvider, null);
}
public static XmlStreamUtils create(final XmlCodecProvider codecProvider, final SchemaContext schemaContext) {
return new XmlStreamUtils(codecProvider, schemaContext);
}
@VisibleForTesting
static void writeAttribute(final XMLStreamWriter writer, final Entry<QName, String> attribute, final RandomPrefix randomPrefix)
throws XMLStreamException {
final QName key = attribute.getKey();
final String prefix = randomPrefix.encodePrefix(key.getNamespace());
writer.writeAttribute("xmlns:" + prefix, key.getNamespace().toString());
writer.writeAttribute(prefix, key.getNamespace().toString(), key.getLocalName(), attribute.getValue());
}
/**
* Write a value into a XML stream writer. This method assumes the start and end of element is
* emitted by the caller.
*
* @param writer XML Stream writer
* @param schemaNode Schema node that describes the value
* @param value data value
* @param parent optional parameter of a module QName owning the leaf definition
* @throws XMLStreamException if an encoding problem occurs
*/
public void writeValue(@Nonnull final XMLStreamWriter writer, @Nonnull final SchemaNode schemaNode, final Object value, final Optional<QNameModule> parent) throws XMLStreamException {
if (value == null) {
LOG.debug("Value of {}:{} is null, not encoding it", schemaNode.getQName().getNamespace(), schemaNode.getQName().getLocalName());
return;
}
Preconditions.checkArgument(schemaNode instanceof LeafSchemaNode || schemaNode instanceof LeafListSchemaNode,
"Unable to write value for node %s, only nodes of type: leaf and leaf-list can be written at this point", schemaNode.getQName());
TypeDefinition<?> type = schemaNode instanceof LeafSchemaNode ?
((LeafSchemaNode) schemaNode).getType():
((LeafListSchemaNode) schemaNode).getType();
TypeDefinition<?> baseType = XmlUtils.resolveBaseTypeFrom(type);
if (schemaContext.isPresent() && baseType instanceof LeafrefTypeDefinition) {
LeafrefTypeDefinition leafrefTypeDefinition = (LeafrefTypeDefinition) baseType;
baseType = SchemaContextUtil.getBaseTypeForLeafRef(leafrefTypeDefinition, schemaContext.get(), schemaNode);
Verify.verifyNotNull(baseType, "Unable to find base type for leafref node '%s'.", schemaNode.getPath());
}
writeValue(writer, baseType, value, parent);
}
public void writeValue(@Nonnull final XMLStreamWriter writer, @Nonnull final SchemaNode schemaNode, final Object value) throws XMLStreamException {
writeValue(writer, schemaNode, value, Optional.absent());
}
public void writeValue(@Nonnull final XMLStreamWriter writer, @Nonnull final SchemaNode schemaNode, final Object value, final QNameModule parent) throws XMLStreamException {
writeValue(writer, schemaNode, value, Optional.of(parent));
}
/**
* Write a value into a XML stream writer. This method assumes the start and end of element is
* emitted by the caller.
*
* @param writer XML Stream writer
* @param type data type. In case of leaf ref this should be the type of leaf being referenced
* @param value data value
* @param parent optional parameter of a module QName owning the leaf definition
* @throws XMLStreamException if an encoding problem occurs
*/
public void writeValue(@Nonnull final XMLStreamWriter writer, @Nonnull final TypeDefinition<?> type, final Object value, final Optional<QNameModule> parent) throws XMLStreamException {
if (value == null) {
LOG.debug("Value of {}:{} is null, not encoding it", type.getQName().getNamespace(), type.getQName().getLocalName());
return;
}
TypeDefinition<?> baseType = XmlUtils.resolveBaseTypeFrom(type);
if (baseType instanceof IdentityrefTypeDefinition) {
if (parent.isPresent()) {
write(writer, (IdentityrefTypeDefinition) baseType, value, parent);
} else {
write(writer, (IdentityrefTypeDefinition) baseType, value, Optional.absent());
}
} else if (baseType instanceof InstanceIdentifierTypeDefinition) {
write(writer, (InstanceIdentifierTypeDefinition) baseType, value);
} else {
final TypeDefinitionAwareCodec<Object, ?> codec = codecProvider.codecFor(type);
String text;
if (codec != null) {
try {
text = codec.serialize(value);
} catch (ClassCastException e) {
LOG.error("Provided node value {} did not have type {} required by mapping. Using stream instead.", value, type, e);
text = String.valueOf(value);
}
} else {
LOG.error("Failed to find codec for {}, falling back to using stream", type);
text = String.valueOf(value);
}
writer.writeCharacters(text);
}
}
public void writeValue(@Nonnull final XMLStreamWriter writer, @Nonnull final TypeDefinition<?> type, final Object value, final QNameModule parent) throws XMLStreamException {
writeValue(writer, type, value, Optional.of(parent));
}
public void writeValue(@Nonnull final XMLStreamWriter writer, @Nonnull final TypeDefinition<?> type, final Object value) throws XMLStreamException {
writeValue(writer, type, value, Optional.absent());
}
@VisibleForTesting
static void write(@Nonnull final XMLStreamWriter writer, @Nonnull final IdentityrefTypeDefinition type, @Nonnull final Object value, final Optional<QNameModule> parent) throws XMLStreamException {
if (value instanceof QName) {
final QName qname = (QName) value;
final String prefix = "x";
//in case parent is present and same as element namespace write value without namespace
if (parent.isPresent() && qname.getNamespace().equals(parent.get().getNamespace())){
writer.writeCharacters(qname.getLocalName());
} else {
final String ns = qname.getNamespace().toString();
writer.writeNamespace(prefix, ns);
writer.writeCharacters(prefix + ':' + qname.getLocalName());
}
} else {
LOG.debug("Value of {}:{} is not a QName but {}", type.getQName().getNamespace(), type.getQName().getLocalName(), value.getClass());
writer.writeCharacters(String.valueOf(value));
}
}
private void write(@Nonnull final XMLStreamWriter writer, @Nonnull final InstanceIdentifierTypeDefinition type, @Nonnull final Object value) throws XMLStreamException {
if (value instanceof YangInstanceIdentifier) {
writeInstanceIdentifier(writer, (YangInstanceIdentifier)value);
} else {
LOG.warn("Value of {}:{} is not an InstanceIdentifier but {}", type.getQName().getNamespace(), type.getQName().getLocalName(), value.getClass());
writer.writeCharacters(String.valueOf(value));
}
}
public void writeInstanceIdentifier(final XMLStreamWriter writer, final YangInstanceIdentifier value) throws XMLStreamException {
if (schemaContext.isPresent()) {
RandomPrefixInstanceIdentifierSerializer iiCodec = new RandomPrefixInstanceIdentifierSerializer(schemaContext.get());
String serializedValue = iiCodec.serialize(value);
writeNamespaceDeclarations(writer,iiCodec.getPrefixes());
writer.writeCharacters(serializedValue);
} else {
LOG.warn("Schema context not present in {}, serializing {} without schema.",this,value);
writeInstanceIdentifier(writer, value);
}
}
private static void writeNamespaceDeclarations(final XMLStreamWriter writer, final Iterable<Entry<URI, String>> prefixes) throws XMLStreamException {
for (Entry<URI, String> e: prefixes) {
final String ns = e.getKey().toString();
final String p = e.getValue();
writer.writeNamespace(p, ns);
}
}
}