package client.net.sf.saxon.ce.style;
import client.net.sf.saxon.ce.expr.Expression;
import client.net.sf.saxon.ce.expr.Literal;
import client.net.sf.saxon.ce.expr.instruct.Executable;
import client.net.sf.saxon.ce.expr.instruct.ForEach;
import client.net.sf.saxon.ce.expr.sort.SortExpression;
import client.net.sf.saxon.ce.expr.sort.SortKeyDefinition;
import client.net.sf.saxon.ce.om.AttributeCollection;
import client.net.sf.saxon.ce.om.Axis;
import client.net.sf.saxon.ce.om.StandardNames;
import client.net.sf.saxon.ce.trans.XPathException;
import client.net.sf.saxon.ce.type.ItemType;
import client.net.sf.saxon.ce.value.Cardinality;
/**
* Handler for xsl:for-each elements in stylesheet. <br>
*/
public class XSLForEach extends StyleElement {
private Expression select = null;
private boolean containsTailCall = false;
private int threads = 0;
/**
* Determine whether this node is an instruction.
* @return true - it is an instruction
*/
public boolean isInstruction() {
return true;
}
/**
* Specify that xsl:sort is a permitted child
*/
protected boolean isPermittedChild(StyleElement child) {
return (child instanceof XSLSort);
}
/**
* Determine the type of item returned by this instruction (only relevant if
* it is an instruction).
* @return the item type returned
*/
protected ItemType getReturnedItemType() {
return getCommonChildItemType();
}
protected boolean markTailCalls() {
if (Cardinality.allowsMany(select.getCardinality())) {
return false;
} else {
StyleElement last = getLastChildInstruction();
containsTailCall = last != null && last.markTailCalls();
return containsTailCall;
}
}
/**
* Determine whether this type of element is allowed to contain a template-body
* @return true: yes, it may contain a template-body
*/
public boolean mayContainSequenceConstructor() {
return true;
}
public void prepareAttributes() throws XPathException {
AttributeCollection atts = getAttributeList();
String selectAtt = null;
for (int a=0; a<atts.getLength(); a++) {
int nc = atts.getNameCode(a);
String f = getNamePool().getClarkName(nc);
if (f.equals(StandardNames.SELECT)) {
selectAtt = atts.getValue(a);
} else {
checkUnknownAttribute(nc);
}
}
if (selectAtt==null) {
reportAbsence("select");
} else {
select = makeExpression(selectAtt);
}
}
public void validate(Declaration decl) throws XPathException {
checkSortComesFirst(false);
select = typeCheck(select);
}
public Expression compile(Executable exec, Declaration decl) throws XPathException {
SortKeyDefinition[] sortKeys = makeSortKeys(decl);
Expression sortedSequence = select;
if (sortKeys != null) {
sortedSequence = new SortExpression(select, sortKeys);
}
Expression block = compileSequenceConstructor(exec, decl, iterateAxis(Axis.CHILD));
if (block == null) {
// body of for-each is empty: it's a no-op.
return Literal.makeEmptySequence();
}
try {
return new ForEach(sortedSequence, makeExpressionVisitor().simplify(block), containsTailCall);
} catch (XPathException err) {
compileError(err);
return null;
}
}
}
// 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.