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The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// 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.style;
import net.sf.saxon.expr.*;
import net.sf.saxon.expr.instruct.SimpleNodeConstructor;
import net.sf.saxon.expr.parser.RetainedStaticContext;
import net.sf.saxon.functions.SystemFunction;
import net.sf.saxon.om.*;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.tree.iter.AxisIterator;
import net.sf.saxon.type.BuiltInAtomicType;
import net.sf.saxon.type.Type;
import net.sf.saxon.value.StringValue;
import net.sf.saxon.value.Whitespace;
/**
* Common superclass for XSLT elements whose content template produces a text
* value: xsl:text, xsl:value-of, xsl:attribute, xsl:comment, xsl:namespace, and xsl:processing-instruction
*/
public abstract class XSLLeafNodeConstructor extends StyleElement {
//protected String stringValue = null;
/*@Nullable*/ protected Expression select = null;
/**
* Method for use by subclasses (processing-instruction and namespace) that take
* a name and a select attribute
*
* @return the expression defining the name attribute
*/
protected Expression prepareAttributesNameAndSelect() {
Expression name = null;
String nameAtt = null;
String selectAtt = null;
for (AttributeInfo att : attributes()) {
NodeName attName = att.getNodeName();
String f = attName.getDisplayName();
String value = att.getValue();
if (f.equals("name")) {
nameAtt = Whitespace.trim(value);
name = makeAttributeValueTemplate(nameAtt, att);
} else if (f.equals("select")) {
selectAtt = value;
select = makeExpression(selectAtt, att);
} else {
checkUnknownAttribute(attName);
}
}
if (nameAtt == null) {
reportAbsence("name");
}
return name;
}
/**
* Determine whether this node is an instruction.
*
* @return true - it is an instruction
*/
@Override
public boolean isInstruction() {
return true;
}
/**
* Determine whether this type of element is allowed to contain a template-body
*
* @return true: yes, it may contain a template-body
*/
@Override
protected boolean mayContainSequenceConstructor() {
return true;
}
@Override
public void validate(ComponentDeclaration decl) throws XPathException {
if (select != null && hasChildNodes()) {
String errorCode = getErrorCodeForSelectPlusContent();
compileError("An " + getDisplayName() + " element with a select attribute must be empty", errorCode);
}
AxisIterator kids = iterateAxis(AxisInfo.CHILD);
NodeInfo first = kids.next();
if (select == null) {
if (first == null) {
// there are no child nodes and no select attribute
//stringValue = "";
select = new StringLiteral(StringValue.EMPTY_STRING);
select.setRetainedStaticContext(makeRetainedStaticContext());
} else {
if (kids.next() == null && !isExpandingText()) {
// there is exactly one child node
if (first.getNodeKind() == Type.TEXT) {
// it is a text node: optimize for this case
select = new StringLiteral(first.getUnicodeStringValue());
select.setRetainedStaticContext(makeRetainedStaticContext());
}
}
}
}
}
/**
* Get the error code to be returned when the element has a select attribute but is not empty.
*
* @return the error code defined for this condition, for this particular instruction
*/
protected abstract String getErrorCodeForSelectPlusContent();
protected void compileContent(Compilation exec, ComponentDeclaration decl, SimpleNodeConstructor inst, Expression separator) throws XPathException {
if (separator == null) {
separator = new StringLiteral(StringValue.SINGLE_SPACE);
}
try {
if (select == null) {
select = compileSequenceConstructor(exec, decl, true);
}
select = makeSimpleContentConstructor(select, separator, getStaticContext());
inst.setSelect(select);
} catch (XPathException err) {
compileError(err);
}
}
/**
* Construct an expression that implements the rules of "constructing simple content":
* given an expression to select the base sequence, and an expression to compute the separator,
* build an (unoptimized) expression to produce the value of the node as a string.
*
* @param select the expression that selects the base sequence
* @param separator the expression that computes the separator
* @param env the static context
* @return an expression that returns a string containing the string value of the constructed node
*/
public static Expression makeSimpleContentConstructor(Expression select, Expression separator, StaticContext env) {
RetainedStaticContext rsc = select.getLocalRetainedStaticContext();
if (rsc == null) {
rsc = env.makeRetainedStaticContext();
}
// Merge adjacent text nodes
select = AdjacentTextNodeMerger.makeAdjacentTextNodeMerger(select);
// Atomize the result
select = Atomizer.makeAtomizer(select, null);
// Convert each atomic value to a string
select = new AtomicSequenceConverter(select, BuiltInAtomicType.STRING);
select.setRetainedStaticContext(rsc);
((AtomicSequenceConverter) select).allocateConverterStatically(env.getConfiguration(), false);
// Join the resulting strings with a separator
if (select.getCardinality() != StaticProperty.EXACTLY_ONE) {
select = SystemFunction.makeCall("string-join", rsc, select, separator);
}
// All that's left for the instruction to do is to construct the right kind of node
return select;
}
}