java.io.Serializable
, javax.xml.transform.SourceLocator
, Container
, Expression
, InstructionInfoProvider
public class ExtensionFunctionCall extends FunctionCall
Note that the binding of an XPath function call to a Java method is done in
class JavaExtensionLibrary
locationId, staticProperties
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
argument
Constructor | Description |
---|---|
ExtensionFunctionCall() |
Default constructor
|
Modifier and Type | Method | Description |
---|---|---|
void |
checkArguments(StaticContext env) |
Method called by the expression parser when all arguments have been supplied
|
int |
computeCardinality() |
|
protected java.lang.Object |
getField(java.lang.reflect.Field field,
java.lang.Object instance) |
Access a field.
|
int |
getIntrinsicDependencies() |
Determine which aspects of the context the expression depends on.
|
ItemType |
getItemType(TypeHierarchy th) |
Determine the data type of the expression, if possible.
|
java.lang.Class |
getTargetClass() |
Get the class containing the method being called
|
java.lang.reflect.AccessibleObject |
getTargetMethod() |
Get the target method (or field, or constructor) being called
|
void |
init(int nameCode,
java.lang.Class theClass,
java.lang.reflect.AccessibleObject object,
Configuration config) |
Initialization: creates an ExtensionFunctionCall
|
protected java.lang.Object |
invokeConstructor(java.lang.reflect.Constructor constructor,
java.lang.Object[] params) |
Invoke a constructor.
|
protected java.lang.Object |
invokeMethod(java.lang.reflect.Method method,
java.lang.Object instance,
java.lang.Object[] params) |
Invoke a method.
|
SequenceIterator |
iterate(XPathContext context) |
Evaluate the function.
|
Expression |
preEvaluate(StaticContext env) |
preEvaluate: this method suppresses compile-time evaluation by doing nothing
(because the external function might have side-effects and might use the context)
|
boolean |
usesFocus() |
Determine whether this method uses the focus.
|
adoptChildExpression, checkPermittedContents, computeDependencies, computeSpecialProperties, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError
checkArgumentCount, display, getArguments, getDisplayName, getFunctionNameCode, getNumberOfArguments, iterateSubExpressions, optimize, promote, replaceSubExpression, setArguments, setFunctionNameCode, simplify, simplifyArguments, typeCheck
public void init(int nameCode, java.lang.Class theClass, java.lang.reflect.AccessibleObject object, Configuration config)
nameCode
- the name code of the function, for display purposestheClass
- the Java class containing the method to be calledobject
- the method, field, or constructor of the Java class to be calledpublic Expression preEvaluate(StaticContext env)
preEvaluate
in class FunctionCall
public void checkArguments(StaticContext env) throws XPathException
checkArguments
in class FunctionCall
XPathException
public int getIntrinsicDependencies()
getIntrinsicDependencies
in class ComputedExpression
public SequenceIterator iterate(XPathContext context) throws XPathException
iterate
in interface Expression
iterate
in class ComputedExpression
context
- The context in which the function is to be evaluatedXPathException
- if the function cannot be evaluated.public java.lang.Class getTargetClass()
public java.lang.reflect.AccessibleObject getTargetMethod()
public ItemType getItemType(TypeHierarchy th)
This method will always return a result, though it may be the best approximation that is available at the time.
th
- public int computeCardinality()
computeCardinality
in class ComputedExpression
public boolean usesFocus()
protected java.lang.Object invokeConstructor(java.lang.reflect.Constructor constructor, java.lang.Object[] params) throws java.lang.InstantiationException, java.lang.IllegalAccessException, java.lang.reflect.InvocationTargetException
constructor
- The constructor to be invokedparams
- The parameters to be passed to the constructorjava.lang.InstantiationException
- if the invocation throws an InstantiationExceptionjava.lang.IllegalAccessException
- if the invocation throws an IllegalAccessExceptionjava.lang.reflect.InvocationTargetException
- if the invocation throws an InvocationTargetException (which happens
when the constructor itself throws an exception)protected java.lang.Object invokeMethod(java.lang.reflect.Method method, java.lang.Object instance, java.lang.Object[] params) throws java.lang.IllegalAccessException, java.lang.reflect.InvocationTargetException
method
- The method to be invokedinstance
- The object on which the method is to be invoked. This is set to null if the
method is static.params
- The parameters to be passed to the methodjava.lang.IllegalAccessException
- if the invocation throws an IllegalAccessExceptionjava.lang.reflect.InvocationTargetException
- if the invocation throws an InvocationTargetException (which happens
when the method itself throws an exception)protected java.lang.Object getField(java.lang.reflect.Field field, java.lang.Object instance) throws java.lang.IllegalAccessException
field
- The field to be retrievedinstance
- The object whose field is to be retrieved. This is set to null if the
field is static.java.lang.IllegalAccessException
- if the invocation throws an IllegalAccessException