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// Copyright (c) 2018-2023 Saxonica Limited
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

package net.sf.saxon.tree.wrapper;

import net.sf.saxon.event.Receiver;
import net.sf.saxon.om.*;
import net.sf.saxon.pattern.AnyNodeTest;
import net.sf.saxon.pattern.NodePredicate;
import net.sf.saxon.pattern.NodeTest;
import net.sf.saxon.s9api.Location;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.transpile.CSharpModifiers;
import net.sf.saxon.tree.NamespaceNode;
import net.sf.saxon.tree.iter.AxisIterator;
import net.sf.saxon.tree.iter.EmptyIterator;
import net.sf.saxon.tree.util.Navigator;
import net.sf.saxon.type.Type;
import net.sf.saxon.value.StringValue;

/**
 * A node in the XML parse tree representing an XML element, character content, or attribute.
 * 

This implementation of the NodeInfo interface contains common code used by many "wrapper" implementations * for external data models.

* */ public abstract class AbstractNodeWrapper implements NodeInfo, VirtualNode { protected TreeInfo treeInfo; @Override public TreeInfo getTreeInfo() { return treeInfo; } /** * Get the node underlying this virtual node. If this is a VirtualNode the method * will automatically drill down through several layers of wrapping. * * @return The underlying node. */ @Override public final Object getRealNode() { return getUnderlyingNode(); } /** * Get the name pool for this node * * @return the NamePool */ public NamePool getNamePool() { return getConfiguration().getNamePool(); } /** * Get the typed value. * * @return the typed value. This will either be a single AtomicValue or a value whose items are * atomic values. * @since 8.5 - signature changed in 9.5 */ @Override public AtomicSequence atomize() throws XPathException { switch (getNodeKind()) { case Type.COMMENT: case Type.PROCESSING_INSTRUCTION: return new StringValue(getUnicodeStringValue()); default: return StringValue.makeUntypedAtomic(getUnicodeStringValue()); } } /** * The equals() method compares nodes for identity. It is defined to give the same result * as isSameNodeInfo(). * * @param other the node to be compared with this node * @return true if this NodeInfo object and the supplied NodeInfo object represent * the same node in the tree. * @since 8.7 Previously, the effect of the equals() method was not defined. Callers * should therefore be aware that third party implementations of the NodeInfo interface may * not implement the correct semantics. It is safer to use isSameNodeInfo() for this reason. * The equals() method has been defined because it is useful in contexts such as a Java Set or HashMap. */ public boolean equals(Object other) { if (!(other instanceof AbstractNodeWrapper)) { return false; } AbstractNodeWrapper ow = (AbstractNodeWrapper) other; return getUnderlyingNode().equals(ow.getUnderlyingNode()); } /** * The hashCode() method obeys the contract for hashCode(): that is, if two objects are equal * (represent the same node) then they must have the same hashCode() * * @since 8.7 Previously, the effect of the equals() and hashCode() methods was not defined. Callers * should therefore be aware that third party implementations of the NodeInfo interface may * not implement the correct semantics. */ public int hashCode() { return getUnderlyingNode().hashCode(); } /** * Get the System ID for the node. * * @return the System Identifier of the entity in the source document containing the node, * or null if not known. Note this is not the same as the base URI: the base URI can be * modified by xml:base, but the system ID cannot. */ @Override @CSharpModifiers(code={"public", "virtual"}) public String getSystemId() { if (treeInfo instanceof GenericTreeInfo) { return ((GenericTreeInfo)treeInfo).getSystemId(); } else { throw new UnsupportedOperationException(); // must implement in subclass } } /** * Set the system ID. Required because NodeInfo implements the JAXP Source interface * @param uri the system ID. */ @Override public void setSystemId(String uri) { throw new UnsupportedOperationException(); } /** * Get the Base URI for the node, that is, the URI used for resolving a relative URI contained * in the node. * * @return the base URI of the node, taking into account xml:base attributes if present */ @Override @CSharpModifiers(code={"public virtual"}) public String getBaseURI() { if (getNodeKind() == Type.NAMESPACE) { return null; } NodeInfo n = this; if (getNodeKind() != Type.ELEMENT) { n = getParent(); } // Look for an xml:base attribute while (n != null) { String xmlbase = n.getAttributeValue(NamespaceUri.XML, "base"); if (xmlbase != null) { return xmlbase; } n = n.getParent(); } // if not found, return the base URI of the document node return getRoot().getSystemId(); } /** * Get line number * * @return the line number of the node in its original source document; or -1 if not available. * Always returns -1 in this implementation. */ @Override public int getLineNumber() { return -1; } /** * Get column number * * @return the column number of the node in its original source document; or -1 if not available */ @Override public int getColumnNumber() { return -1; } /** * Get an immutable copy of this Location object. By default Location objects may be mutable, so they * should not be saved for later use. The result of this operation holds the same location information, * but in an immutable form. */ @Override public Location saveLocation() { return this; } /** * Get the display name of this node. For elements and attributes this is * [prefix:]localname. For unnamed nodes, it is an empty string. * * @return The display name of this node. For a node with no name, return an * empty string. */ @Override @CSharpModifiers(code={"public", "virtual"}) public String getDisplayName() { String prefix = getPrefix(); String local = getLocalPart(); if (prefix.isEmpty()) { return local; } else { return prefix + ":" + local; } } /** * Get the string value of a given attribute of this node. *

The default implementation is suitable for nodes other than elements.

* * @param uri the namespace URI of the attribute name. Supply the empty string for an attribute * that is in no namespace * @param local the local part of the attribute name. * @return the attribute value if it exists, or null if it does not exist. Always returns null * if this node is not an element. * @since 9.4 */ @Override @CSharpModifiers(code = {"public", "virtual"}) public String getAttributeValue(NamespaceUri uri, String local) { return null; } /** * Return an iteration over the nodes reached by the given axis from this node * * @param axisNumber the axis to be used * @return a SequenceIterator that scans the nodes reached by the axis in turn. */ @Override @CSharpModifiers(code={"public", "virtual"}) public AxisIterator iterateAxis(int axisNumber) { return iterateAxis(axisNumber, AnyNodeTest.getInstance()); } /** * Return an iteration over the nodes reached by the given axis from this node. *

This superclass provides implementations of the ancestor, ancestor-or-self, * following, namespace, parent, preceding, self, and preceding-or-ancestor axes. * The other axes are implemented by calling methods iterateAttributes(), * iterateChildren(), iterateDescendants(), and iterateSiblings(), which must * be provided in a subclass.

* * @param axisNumber the axis to be used * @param predicate A pattern to be matched by the returned nodes * @return a SequenceIterator that scans the nodes reached by the axis in turn. */ @Override @CSharpModifiers(code = {"public", "virtual"}) public AxisIterator iterateAxis(int axisNumber, NodePredicate predicate) { NodeTest nodeTest = Navigator.nodeTestFromPredicate(predicate); int nodeKind = getNodeKind(); switch (axisNumber) { case AxisInfo.ANCESTOR: if (nodeKind == Type.DOCUMENT) { return EmptyIterator.ofNodes(); } return new Navigator.AxisFilter( new Navigator.AncestorEnumeration(this, false), nodeTest); case AxisInfo.ANCESTOR_OR_SELF: if (nodeKind == Type.DOCUMENT) { return Navigator.filteredSingleton(this, nodeTest); } return new Navigator.AxisFilter( new Navigator.AncestorEnumeration(this, true), nodeTest); case AxisInfo.ATTRIBUTE: if (nodeKind != Type.ELEMENT) { return EmptyIterator.ofNodes(); } return iterateAttributes(nodeTest); case AxisInfo.CHILD: if (nodeKind == Type.ELEMENT || nodeKind == Type.DOCUMENT) { return iterateChildren(nodeTest); } else { return EmptyIterator.ofNodes(); } case AxisInfo.DESCENDANT: if (nodeKind == Type.ELEMENT || nodeKind == Type.DOCUMENT) { return iterateDescendants(nodeTest, false); } else { return EmptyIterator.ofNodes(); } case AxisInfo.DESCENDANT_OR_SELF: if (nodeKind == Type.ELEMENT || nodeKind == Type.DOCUMENT) { return iterateDescendants(nodeTest, true); } else { return Navigator.filteredSingleton(this, nodeTest); } case AxisInfo.FOLLOWING: return new Navigator.AxisFilter( new Navigator.FollowingEnumeration(this), nodeTest); case AxisInfo.FOLLOWING_SIBLING: switch (nodeKind) { case Type.DOCUMENT: case Type.ATTRIBUTE: case Type.NAMESPACE: return EmptyIterator.ofNodes(); default: return iterateSiblings(nodeTest, true); } case AxisInfo.NAMESPACE: if (nodeKind != Type.ELEMENT) { return EmptyIterator.ofNodes(); } return NamespaceNode.makeIterator(this, nodeTest); case AxisInfo.PARENT: return Navigator.filteredSingleton(getParent(), nodeTest); case AxisInfo.PRECEDING: return new Navigator.AxisFilter( new Navigator.PrecedingEnumeration(this, false), nodeTest); case AxisInfo.PRECEDING_SIBLING: switch (nodeKind) { case Type.DOCUMENT: case Type.ATTRIBUTE: case Type.NAMESPACE: return EmptyIterator.ofNodes(); default: return iterateSiblings(nodeTest, false); } case AxisInfo.SELF: return Navigator.filteredSingleton(this, nodeTest); case AxisInfo.PRECEDING_OR_ANCESTOR: return new Navigator.AxisFilter( new Navigator.PrecedingEnumeration(this, true), nodeTest); default: throw new IllegalArgumentException("Unknown axis number " + axisNumber); } } /** * Return an iterator over the attributes of this element node. * This method is only called after checking that the node is an element. * * @param nodeTest a test that the returned attributes must satisfy * @return an iterator over the attribute nodes. The order of the result, * although arbitrary, must be consistent with document order. */ protected abstract AxisIterator iterateAttributes(NodeTest nodeTest); /** * Return an iterator over the children of this node. * This method is only called after checking that the node is an element or document. * * @param nodeTest a test that the returned attributes must satisfy * @return an iterator over the child nodes, in document order. */ protected abstract AxisIterator iterateChildren(NodeTest nodeTest); /** * Return an iterator over the siblings of this node. * This method is only called after checking that the node is an element, text, comment, or PI node. * * @param nodeTest a test that the returned siblings must satisfy * @param forwards true for following siblings, false for preceding siblings * @return an iterator over the sibling nodes, in axis order. */ protected abstract AxisIterator iterateSiblings(NodeTest nodeTest, boolean forwards); /** * Return an iterator over the descendants of this node. * This method is only called after checking that the node is an element or document node. * * @param nodeTest a test that the returned descendants must satisfy * @param includeSelf true if this node is to be included in the result * @return an iterator over the sibling nodes, in axis order. */ @CSharpModifiers(code={"protected", "virtual"}) protected AxisIterator iterateDescendants(NodeTest nodeTest, boolean includeSelf) { AxisIterator iter = new Navigator.DescendantEnumeration(this, includeSelf, true); if (!(nodeTest instanceof AnyNodeTest)) { iter = new Navigator.AxisFilter(iter, nodeTest); } return iter; } /** * Get all namespace declarations and undeclarations defined on this element. *

This method is intended primarily for internal use. User applications needing * information about the namespace context of a node should use iterateAxis(Axis.NAMESPACE). * (However, not all implementations support the namespace axis, whereas all implementations are * required to support this method.)

*

This implementation of the method is suitable for all nodes other than elements; it returns * an empty array.

* * @param buffer If this is non-null, and the result array fits in this buffer, then the result * may overwrite the contents of this array, to avoid the cost of allocating a new array on the heap. * @return An array of namespace binding objects representing the namespace declarations and undeclarations present on * this element. For a node other than an element, return null. * If the uri part is "", then this is a namespace undeclaration rather than a declaration. * The XML namespace is never included in the list. If the supplied array is larger than required, * then the first unused entry will be set to null. *

For a node other than an element, the method returns null.

*/ @Override @CSharpModifiers(code = {"public", "virtual"}) public NamespaceBinding[] getDeclaredNamespaces(NamespaceBinding[] buffer) { return new NamespaceBinding[0]; } /** * Get all the namespace bindings that are in-scope for this element. *

For an element return all the prefix-to-uri bindings that are in scope. This may include * a binding to the default namespace (represented by a prefix of ""). It will never include * "undeclarations" - that is, the namespace URI will never be empty; the effect of an undeclaration * is to remove a binding from the in-scope namespaces, not to add anything.

*

For a node other than an element, returns null.

* * @return the in-scope namespaces for an element, or null for any other kind of node. */ @Override @CSharpModifiers(code={"public", "virtual"}) public NamespaceMap getAllNamespaces() { if (getNodeKind() == Type.ELEMENT) { throw new AssertionError("getAllNamespaces() not implemented for " + getClass()); } return null; } /** * Get the root node - always a document node with this tree implementation * * @return the NodeInfo representing the containing document */ @Override public NodeInfo getRoot() { NodeInfo p = this; while (true) { NodeInfo q = p.getParent(); if (q==null) { return p; } p = q; } } /** * Determine whether the node has any children. * This implementation calls iterateAxis, so the subclass implementation of iterateAxis * must avoid calling this method. */ @Override @CSharpModifiers(code = {"public", "virtual"}) public boolean hasChildNodes() { switch (getNodeKind()) { case Type.DOCUMENT: case Type.ELEMENT: return iterateAxis(AxisInfo.CHILD).next() != null; default: return false; } } /** * Get the fingerprint of the node * * @return the node's fingerprint, or -1 for an unnamed node * @throws UnsupportedOperationException if this method is called for a node where * hasFingerprint() returns false; */ @Override @CSharpModifiers(code = {"public", "virtual"}) public int getFingerprint() { throw new UnsupportedOperationException(); } /** * Test whether a fingerprint is available for the node name */ @Override @CSharpModifiers(code = {"public", "virtual"}) public boolean hasFingerprint() { return false; } }




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