net.sf.saxon.instruct.ParentNodeConstructor Maven / Gradle / Ivy
package net.sf.saxon.instruct;
import net.sf.saxon.expr.*;
import net.sf.saxon.om.Validation;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.ItemType;
import net.sf.saxon.type.SchemaType;
import net.sf.saxon.type.SimpleType;
import java.util.Iterator;
/**
* An abstract class to act as a common parent for instructions that create element nodes
* and document nodes.
*/
public abstract class ParentNodeConstructor extends Instruction {
protected Expression content;
private boolean lazyConstruction = false;
private boolean namespaceSensitiveType;
//protected boolean contentMayContainAttributesOrNamespaces = true;
int validation = Validation.PRESERVE;
private SchemaType schemaType;
private String baseURI;
/**
* Create a document or element node constructor instruction
*/
public ParentNodeConstructor() {}
/**
* Set the static base URI of the instruction
* @param uri the static base URI
*/
public void setBaseURI(String uri) {
baseURI = uri;
}
/**
* Get the static base URI of the instruction
* @return the static base URI
*/
public String getBaseURI() {
return baseURI;
}
/**
* Indicate that lazy construction should (or should not) be used. Note that
* this request will be ignored if validation is required
* @param lazy set to true if lazy construction should be used
*/
public void setLazyConstruction(boolean lazy) {
lazyConstruction = lazy;
}
/**
* Establish whether lazy construction is to be used
* @return true if lazy construction is to be used
*/
public final boolean isLazyConstruction() {
return lazyConstruction;
}
/**
* Set the schema type to be used for validation
* @param type the type to be used for validation. (For a document constructor, this is the required
* type of the document element)
*/
public void setSchemaType(SchemaType type) {
schemaType = type;
namespaceSensitiveType = (type instanceof SimpleType) && ((SimpleType)type).isNamespaceSensitive();
}
/**
* Get the schema type chosen for validation; null if not defined
* @return the type to be used for validation. (For a document constructor, this is the required
* type of the document element)
*/
public SchemaType getSchemaType() {
return schemaType;
}
/**
* Determine whether the schema type is namespace sensitive. The result is undefined if schemaType is null.
* @return true if the schema type is namespace sensitive
*/
public boolean isNamespaceSensitive() {
return namespaceSensitiveType;
}
/**
* Set the validation mode for the new document or element node
* @param mode the validation mode, for example {@link Validation#STRICT}
*/
public void setValidationMode(int mode) {
validation = mode;
}
/**
* Get the validation mode for this instruction
* @return the validation mode, for example {@link Validation#STRICT} or {@link Validation#PRESERVE}
*/
public int getValidationMode() {
return validation;
}
/**
* Get the implied validation mode for this
*/
/**
* Set the expression that constructs the content of the element
* @param content the content expression
*/
public void setContentExpression(Expression content) {
this.content = content;
adoptChildExpression(content);
}
/**
* Get the expression that constructs the content of the element
* @return the content expression
*/
public Expression getContentExpression() {
return content;
}
/**
* Get the cardinality of the sequence returned by evaluating this instruction
* @return the static cardinality
*/
public int computeCardinality() {
return StaticProperty.EXACTLY_ONE;
}
/**
* Simplify an expression. This performs any static optimization (by rewriting the expression
* as a different expression). The default implementation does nothing.
* @return the simplified expression
* @throws net.sf.saxon.trans.XPathException
* if an error is discovered during expression rewriting
* @param visitor an expression visitor
*/
public Expression simplify(ExpressionVisitor visitor) throws XPathException {
content = visitor.simplify(content);
return this;
}
public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
content = visitor.typeCheck(content, contextItemType);
// TypeHierarchy th = visitor.getConfiguration().getTypeHierarchy();
// ItemType contentItemType = content.getItemType(th);
// contentMayContainAttributesOrNamespaces =
// th.relationship(contentItemType, NodeKindTest.ATTRIBUTE) != TypeHierarchy.DISJOINT &&
// th.relationship(contentItemType, NodeKindTest.NAMESPACE) != TypeHierarchy.DISJOINT;
adoptChildExpression(content);
verifyLazyConstruction();
checkContentSequence(visitor.getStaticContext());
return this;
}
/**
* Check that the child instructions don't violate any obvious constraints for this kind of node
* @param env the static context
* @throws XPathException
*/
protected abstract void checkContentSequence(StaticContext env) throws XPathException;
public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
content = visitor.optimize(content, contextItemType);
adoptChildExpression(content);
return this;
}
/**
* Handle promotion offers, that is, non-local tree rewrites.
* @param offer The type of rewrite being offered
* @throws net.sf.saxon.trans.XPathException
*/
protected void promoteInst(PromotionOffer offer) throws XPathException {
if (offer.action != PromotionOffer.UNORDERED) {
content = doPromotion(content, offer);
}
}
/**
* Get the immediate sub-expressions of this expression.
* @return an iterator containing the sub-expressions of this expression
*/
public Iterator iterateSubExpressions() {
return new MonoIterator(content);
}
/**
* Replace one subexpression by a replacement subexpression
* @param original the original subexpression
* @param replacement the replacement subexpression
* @return true if the original subexpression is found
*/
public boolean replaceSubExpression(Expression original, Expression replacement) {
boolean found = false;
if (content == original) {
content = replacement;
found = true;
}
return found;
}
/**
* Determine whether this instruction creates new nodes.
* This implementation returns true.
*/
public final boolean createsNewNodes() {
return true;
}
public int getCardinality() {
return StaticProperty.EXACTLY_ONE;
}
/**
* Check that lazy construction is possible for this element
*/
void verifyLazyConstruction() {
if (!isLazyConstruction()) {
return;
}
// Lazy construction is not possible if the expression depends on the values of position() or last(),
// as we can't save these.
if ((getDependencies() & (StaticProperty.DEPENDS_ON_POSITION | StaticProperty.DEPENDS_ON_LAST)) != 0) {
setLazyConstruction(false);
}
// Lazy construction is not possible if validation is required
if (validation == Validation.STRICT || validation == Validation.LAX
|| schemaType != null) {
setLazyConstruction(false);
}
}
/**
* Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited
* by an expression in a source tree.
*
* The default implementation of this method assumes that an expression does no navigation other than
* the navigation done by evaluating its subexpressions, and that the subexpressions are evaluated in the
* same context as the containing expression. The method must be overridden for any expression
* where these assumptions do not hold. For example, implementations exist for AxisExpression, ParentExpression,
* and RootExpression (because they perform navigation), and for the doc(), document(), and collection()
* functions because they create a new navigation root. Implementations also exist for PathExpression and
* FilterExpression because they have subexpressions that are evaluated in a different context from the
* calling expression.
*
* @param pathMap the PathMap to which the expression should be added
* @param pathMapNodeSet the PathMapNodeSet to which the paths embodied in this expression should be added
* @return the pathMapNodeSet representing the points in the source document that are both reachable by this
* expression, and that represent possible results of this expression. For an expression that does
* navigation, it represents the end of the arc in the path map that describes the navigation route. For other
* expressions, it is the same as the input pathMapNode.
*/
public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet) {
PathMap.PathMapNodeSet result = super.addToPathMap(pathMap, pathMapNodeSet);
result.addDescendants();
return new PathMap.PathMapNodeSet(pathMap.makeNewRoot(this));
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//
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