KeyCallpublic final class KeyCall extends FunctionCall
| Fields Summary |
|---|
| private Expression | _nameThe name of the key. | | private Expression | _valueThe value to look up in the key/index. | | private Type | _valueTypeThe value's data type. | | private QName | _resolvedQNameExpanded qname when name is literal. |
| Constructors Summary |
|---|
public KeyCall(QName fname, Vector arguments)Get the parameters passed to function:
key(String name, String value)
key(String name, NodeSet value)
The 'arguments' vector should contain two parameters for key() calls,
one holding the key name and one holding the value(s) to look up. The
vector has only one parameter for id() calls (the key name is always
"##id" for id() calls).
super(fname, arguments);
switch(argumentCount()) {
case 1:
_name = null;
_value = argument(0);
break;
case 2:
_name = argument(0);
_value = argument(1);
break;
default:
_name = _value = null;
break;
}
|
| Methods Summary |
|---|
| public void | addParentDependency()If this call to key() is in a top-level element like another variable
or param, add a dependency between that top-level element and the
referenced key. For example,
and assuming this class represents "key('x', 1)", add a reference
between variable y and key x. Note that if 'x' is unknown statically
in key('x', 1), there's nothing we can do at this point.
// If name unknown statically, there's nothing we can do
if (_resolvedQName == null) return;
SyntaxTreeNode node = this;
while (node != null && node instanceof TopLevelElement == false) {
node = node.getParent();
}
TopLevelElement parent = (TopLevelElement) node;
if (parent != null) {
parent.addDependency(getSymbolTable().getKey(_resolvedQName));
}
| | public void | translate(com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator classGen, com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator methodGen)This method is called when the constructor is compiled in
Stylesheet.compileConstructor() and not as the syntax tree is traversed.
This method will generate byte code that produces an iterator
for the nodes in the node set for the key or id function call.
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
// Returns the KeyIndex object of a given name
final int getKeyIndex = cpg.addMethodref(TRANSLET_CLASS,
"getKeyIndex",
"(Ljava/lang/String;)"+
KEY_INDEX_SIG);
// KeyIndex.setDom(Dom, node) => void
final int keyDom = cpg.addMethodref(KEY_INDEX_CLASS,
"setDom",
"(" + DOM_INTF_SIG + "I)V");
// Initialises a KeyIndex to return nodes with specific values
final int getKeyIterator =
cpg.addMethodref(KEY_INDEX_CLASS,
"getKeyIndexIterator",
"(" + _valueType.toSignature() + "Z)"
+ KEY_INDEX_ITERATOR_SIG);
// Initialise the index specified in the first parameter of key()
il.append(classGen.loadTranslet());
if (_name == null) {
il.append(new PUSH(cpg,"##id"));
} else if (_resolvedQName != null) {
il.append(new PUSH(cpg, _resolvedQName.toString()));
} else {
_name.translate(classGen, methodGen);
}
// Generate following byte code:
//
// KeyIndex ki = translet.getKeyIndex(_name)
// ki.setDom(translet.dom);
// ki.getKeyIndexIterator(_value, true) - for key()
// OR
// ki.getKeyIndexIterator(_value, false) - for id()
il.append(new INVOKEVIRTUAL(getKeyIndex));
il.append(DUP);
il.append(methodGen.loadDOM());
il.append(methodGen.loadCurrentNode());
il.append(new INVOKEVIRTUAL(keyDom));
_value.translate(classGen, methodGen);
il.append((_name != null) ? ICONST_1: ICONST_0);
il.append(new INVOKEVIRTUAL(getKeyIterator));
| | public com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type | typeCheck(com.sun.org.apache.xalan.internal.xsltc.compiler.SymbolTable stable)Type check the parameters for the id() or key() function.
The index name (for key() call only) must be a string or convertable
to a string, and the lookup-value must be a string or a node-set.
final Type returnType = super.typeCheck(stable);
// Run type check on the key name (first argument) - must be a string,
// and if it is not it must be converted to one using string() rules.
if (_name != null) {
final Type nameType = _name.typeCheck(stable);
if (_name instanceof LiteralExpr) {
final LiteralExpr literal = (LiteralExpr) _name;
_resolvedQName =
getParser().getQNameIgnoreDefaultNs(literal.getValue());
}
else if (nameType instanceof StringType == false) {
_name = new CastExpr(_name, Type.String);
}
}
// Run type check on the value for this key. This value can be of
// any data type, so this should never cause any type-check errors.
// If the value is a reference, then we have to defer the decision
// of how to process it until run-time.
// If the value is known not to be a node-set, then it should be
// converted to a string before the lookup is done. If the value is
// known to be a node-set then this process (convert to string, then
// do lookup) should be applied to every node in the set, and the
// result from all lookups should be added to the resulting node-set.
_valueType = _value.typeCheck(stable);
if (_valueType != Type.NodeSet
&& _valueType != Type.Reference
&& _valueType != Type.String) {
_value = new CastExpr(_value, Type.String);
_valueType = _value.typeCheck(stable);
}
// If in a top-level element, create dependency to the referenced key
addParentDependency();
return returnType;
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