package client.net.sf.saxon.ce.style;
import com.google.gwt.logging.client.LogConfiguration;
import client.net.sf.saxon.ce.LogController;
import client.net.sf.saxon.ce.expr.Expression;
import client.net.sf.saxon.ce.expr.Literal;
import client.net.sf.saxon.ce.expr.instruct.Choose;
import client.net.sf.saxon.ce.expr.instruct.Executable;
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.Value;
/**
* Handler for xsl:if elements in stylesheet. <br>
* The xsl:if element has a mandatory attribute test, a boolean expression.
* The content is output if the test condition is true.
*/
public class XSLIf extends StyleElement {
private Expression test;
/**
* Determine whether this node is an instruction.
* @return true - it is an instruction
*/
public boolean isInstruction() {
return true;
}
/**
* 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();
}
/**
* 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 {
test = prepareTestAttribute(this);
if (test==null) {
reportAbsence("test");
}
}
/**
* Process all the attributes, for an element where the only permitted attribute is "test"
* @param se the containing element
* @return the expression represented by the test attribute, or null if the attribute is absent
* @throws XPathException if an error is encountered
*/
public static Expression prepareTestAttribute(StyleElement se) throws XPathException {
String testAtt=null;
AttributeCollection atts = se.getAttributeList();
for (int a=0; a<atts.getLength(); a++) {
int nc = atts.getNameCode(a);
String f = se.getNamePool().getClarkName(nc);
if (f.equals(StandardNames.TEST)) {
testAtt = atts.getValue(a);
} else {
se.checkUnknownAttribute(nc);
}
}
if (testAtt==null) {
return null;
} else {
return se.makeExpression(testAtt);
}
}
public static String getTestAttribute(StyleElement se) throws XPathException {
String testAtt=null;
AttributeCollection atts = se.getAttributeList();
for (int a=0; a<atts.getLength(); a++) {
int nc = atts.getNameCode(a);
String f = se.getNamePool().getClarkName(nc);
if (f.equals(StandardNames.TEST)) {
testAtt = atts.getValue(a);
} else {
se.checkUnknownAttribute(nc);
}
}
return testAtt;
}
public void validate(Declaration decl) throws XPathException {
test = typeCheck(test);
}
/**
* Mark tail-recursive calls on stylesheet functions. For most instructions, this does nothing.
*/
public boolean markTailCalls() {
StyleElement last = getLastChildInstruction();
return last != null && last.markTailCalls();
}
public Expression compile(Executable exec, Declaration decl) throws XPathException {
if (test instanceof Literal) {
Value testVal = ((Literal)test).getValue();
// condition known statically, so we only need compile the code if true.
// This can happen with expressions such as test="function-available('abc')".
try {
if (testVal.effectiveBooleanValue()) {
return compileSequenceConstructor(exec, decl, iterateAxis(Axis.CHILD));
// Block block = new Block();
// block.setLocationId(allocateLocationId(getSystemId(), getLineNumber()));
// compileChildren(exec, block, true);
// return block.simplify(getStaticContext());
} else {
return null;
}
} catch (XPathException err) {
// fall through to non-optimizing case
}
}
Expression action = compileSequenceConstructor(exec, decl, iterateAxis(Axis.CHILD));
if (action == null) {
return null;
}
Expression[] conditions = {test};
Expression[] actions = {action};
Choose inst = new Choose(conditions, actions);
if (LogConfiguration.loggingIsEnabled() && LogController.traceIsEnabled()) {
inst.AddTraceProperty("test", getTestAttribute(this));
}
return inst;
}
}
// 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.