net.sf.saxon.dotnet
Class DotNetExtensionFunctionCall

java.lang.Object
  extended by net.sf.saxon.expr.Expression
      extended by net.sf.saxon.expr.FunctionCall
          extended by net.sf.saxon.dotnet.DotNetExtensionFunctionCall
All Implemented Interfaces:
java.io.Serializable, javax.xml.transform.SourceLocator, EvaluableItem, SequenceIterable, InstructionInfoProvider

public class DotNetExtensionFunctionCall
extends FunctionCall

This class acts as a container for an extension function defined to call a method in a user-defined .NET class.

Note that the binding of an XPath function call to a .NET method is done in class DotNetExtensionLibrary

See Also:
Serialized Form

Field Summary
static cli.System.Type CLI_ARRAYLIST
           
static cli.System.Type CLI_BOOLEAN
           
static cli.System.Type CLI_DECIMAL
           
static cli.System.Type CLI_DOCUMENTINFO
           
static cli.System.Type CLI_DOUBLE
           
static cli.System.Type CLI_ICOLLECTION
           
static cli.System.Type CLI_IENUMERABLE
           
static cli.System.Type CLI_INT16
           
static cli.System.Type CLI_INT32
           
static cli.System.Type CLI_INT64
           
static cli.System.Type CLI_ITEM
           
static cli.System.Type CLI_NODEINFO
           
static cli.System.Type CLI_OBJECT
           
static cli.System.Type CLI_SEQUENCEITERATOR
           
static cli.System.Type CLI_SINGLE
           
static cli.System.Type CLI_STRING
           
static cli.System.Type CLI_VALUE
           
 
Fields inherited from class net.sf.saxon.expr.FunctionCall
argument
 
Fields inherited from class net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
 
Constructor Summary
DotNetExtensionFunctionCall()
          Default constructor
 
Method Summary
 PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
          Add a representation of this expression to a PathMap.
 void checkArguments(ExpressionVisitor visitor)
          Method called by the expression parser when all arguments have been supplied
 int computeCardinality()
          Compute the static cardinality of this expression
static Value convertFromDotNet(java.lang.Object result, cli.System.Type returnType, XPathContext context)
           
static java.lang.Object convertToDotNet(Value value, cli.System.Type targetType, XPathContext context)
          Convert an XPath value to a .NET object
 Expression copy()
          Copy an expression.
protected  java.lang.Object getField(FieldInfo 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.
protected  java.lang.Object getProperty(PropertyInfo property, java.lang.Object instance)
          Access a property.
 cli.System.Type getTargetClass()
          Get the class containing the method being called
 MemberInfo getTargetMethod()
          Get the target method (or field, property, or constructor) being called
 void init(StructuredQName functionName, cli.System.Type theClass, MemberInfo object, Configuration config)
          Initialization: creates an ExtensionFunctionCall
protected  java.lang.Object invokeConstructor(ConstructorInfo constructor, java.lang.Object[] params)
          Invoke a constructor.
protected  java.lang.Object invokeMethod(MethodInfo method, java.lang.Object instance, java.lang.Object[] params)
          Invoke a method.
 SequenceIterator iterate(XPathContext context)
          Evaluate the function.
 Expression preEvaluate(ExpressionVisitor visitor)
          preEvaluate: this method suppresses compile-time evaluation by doing nothing (because the external function might have side-effects and might use the context)
static cli.System.Type type(java.lang.String name)
           
 
Methods inherited from class net.sf.saxon.expr.FunctionCall
addExternalFunctionCallToPathMap, checkArgumentCount, equals, explain, getArguments, getDisplayName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, optimize, promote, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString, typeCheck
 
Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, checkPermittedContents, computeDependencies, computeSpecialProperties, computeStaticProperties, display, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, explain, findParentOf, getCardinality, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getLineNumber, getLocationId, getLocationProvider, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

CLI_BOOLEAN

public static cli.System.Type CLI_BOOLEAN

CLI_INT64

public static cli.System.Type CLI_INT64

CLI_INT32

public static cli.System.Type CLI_INT32

CLI_INT16

public static cli.System.Type CLI_INT16

CLI_DOUBLE

public static cli.System.Type CLI_DOUBLE

CLI_SINGLE

public static cli.System.Type CLI_SINGLE

CLI_DECIMAL

public static cli.System.Type CLI_DECIMAL

CLI_STRING

public static cli.System.Type CLI_STRING

CLI_OBJECT

public static cli.System.Type CLI_OBJECT

CLI_ICOLLECTION

public static cli.System.Type CLI_ICOLLECTION

CLI_IENUMERABLE

public static cli.System.Type CLI_IENUMERABLE

CLI_ARRAYLIST

public static cli.System.Type CLI_ARRAYLIST

CLI_NODEINFO

public static cli.System.Type CLI_NODEINFO

CLI_DOCUMENTINFO

public static cli.System.Type CLI_DOCUMENTINFO

CLI_ITEM

public static cli.System.Type CLI_ITEM

CLI_VALUE

public static cli.System.Type CLI_VALUE

CLI_SEQUENCEITERATOR

public static cli.System.Type CLI_SEQUENCEITERATOR
Constructor Detail

DotNetExtensionFunctionCall

public DotNetExtensionFunctionCall()
Default constructor

Method Detail

init

public void init(StructuredQName functionName,
                 cli.System.Type theClass,
                 MemberInfo object,
                 Configuration config)
Initialization: creates an ExtensionFunctionCall

Parameters:
functionName - the name of the function, for display purposes
theClass - the .NET class containing the method to be called
object - the method, field, or constructor of the .NET class to be called
config - the Saxon configuration

preEvaluate

public Expression preEvaluate(ExpressionVisitor visitor)
preEvaluate: this method suppresses compile-time evaluation by doing nothing (because the external function might have side-effects and might use the context)

Overrides:
preEvaluate in class FunctionCall
Parameters:
visitor - an expression visitor
Returns:
the result of the early evaluation, or the original expression, or potentially a simplified expression

checkArguments

public void checkArguments(ExpressionVisitor visitor)
                    throws XPathException
Method called by the expression parser when all arguments have been supplied

Specified by:
checkArguments in class FunctionCall
Parameters:
visitor - the expression visitor
Throws:
XPathException

addToPathMap

public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap,
                                           PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited by an expression in a source tree.

The default implementation of this method assumes that an expression does no navigation other than the navigation done by evaluating its subexpressions, and that the subexpressions are evaluated in the same context as the containing expression. The method must be overridden for any expression where these assumptions do not hold. For example, implementations exist for AxisExpression, ParentExpression, and RootExpression (because they perform navigation), and for the doc(), document(), and collection() functions because they create a new navigation root. Implementations also exist for PathExpression and FilterExpression because they have subexpressions that are evaluated in a different context from the calling expression.

Overrides:
addToPathMap in class Expression
Parameters:
pathMap - the PathMap to which the expression should be added
pathMapNodeSet -
Returns:
the pathMapNode representing the focus established by this expression, in the case where this expression is the first operand of a path expression or filter expression. For an expression that does navigation, it represents the end of the arc in the path map that describes the navigation route. For other expressions, it is the same as the input pathMapNode.

getIntrinsicDependencies

public int getIntrinsicDependencies()
Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as XPathContext.VARIABLES and XPathContext.CURRENT_NODE

Overrides:
getIntrinsicDependencies in class Expression
Returns:
a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty

copy

public Expression copy()
Copy an expression. This makes a deep copy.

Specified by:
copy in class Expression
Returns:
the copy of the original expression

iterate

public SequenceIterator iterate(XPathContext context)
                         throws XPathException
Evaluate the function.

Specified by:
iterate in interface SequenceIterable
Overrides:
iterate in class Expression
Parameters:
context - The context in which the function is to be evaluated
Returns:
a Value representing the result of the function.
Throws:
XPathException - if the function cannot be evaluated.

getTargetClass

public cli.System.Type getTargetClass()
Get the class containing the method being called

Returns:
the containing class

getTargetMethod

public MemberInfo getTargetMethod()
Get the target method (or field, property, or constructor) being called

Returns:
the target method

getItemType

public ItemType getItemType(TypeHierarchy th)
Determine the data type of the expression, if possible. All expressions return sequences, in general; this method determines the type of the items within the sequence, assuming that (a) this is known in advance, and (b) it is the same for all items in the sequence.

This method will always return a result, though it may be the best approximation that is available at the time.

Specified by:
getItemType in class Expression
Parameters:
th - type hierarchy cache
Returns:
the item type

computeCardinality

public int computeCardinality()
Description copied from class: Expression
Compute the static cardinality of this expression

Specified by:
computeCardinality in class Expression
Returns:
the computed cardinality, as one of the values StaticProperty.ALLOWS_ZERO_OR_ONE, StaticProperty.EXACTLY_ONE, StaticProperty.ALLOWS_ONE_OR_MORE, StaticProperty.ALLOWS_ZERO_OR_MORE

invokeConstructor

protected java.lang.Object invokeConstructor(ConstructorInfo constructor,
                                             java.lang.Object[] params)
                                      throws java.lang.InstantiationException,
                                             java.lang.IllegalAccessException,
                                             java.lang.reflect.InvocationTargetException
Invoke a constructor. This method is provided separately so that it can be refined in a subclass. For example, a subclass might perform tracing of calls, or might trap exceptions.

Parameters:
constructor - The constructor to be invoked
params - The parameters to be passed to the constructor
Returns:
The object returned by the constructor
Throws:
java.lang.InstantiationException - if the invocation throws an InstantiationException
java.lang.IllegalAccessException - if the invocation throws an IllegalAccessException
java.lang.reflect.InvocationTargetException - if the invocation throws an InvocationTargetException (which happens when the constructor itself throws an exception)

invokeMethod

protected java.lang.Object invokeMethod(MethodInfo method,
                                        java.lang.Object instance,
                                        java.lang.Object[] params)
                                 throws java.lang.IllegalAccessException,
                                        java.lang.reflect.InvocationTargetException
Invoke a method. This method is provided separately so that it can be refined in a subclass. For example, a subclass might perform tracing of calls, or might trap exceptions.

Parameters:
method - The method to be invoked
instance - 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 method
Returns:
The object returned by the method
Throws:
java.lang.IllegalAccessException - if the invocation throws an IllegalAccessException
java.lang.reflect.InvocationTargetException - if the invocation throws an InvocationTargetException (which happens when the method itself throws an exception)

getProperty

protected java.lang.Object getProperty(PropertyInfo property,
                                       java.lang.Object instance)
                                throws java.lang.IllegalAccessException
Access a property. This method is provided separately so that it can be refined in a subclass. For example, a subclass might perform tracing of calls, or might trap exceptions.

Parameters:
property - The property to be retrieved
instance - The object whose property is to be retrieved. This is set to null if the property is static.
Returns:
The value of the property
Throws:
java.lang.IllegalAccessException - if the invocation throws an IllegalAccessException

getField

protected java.lang.Object getField(FieldInfo field,
                                    java.lang.Object instance)
                             throws java.lang.IllegalAccessException
Access a field. This method is provided separately so that it can be refined in a subclass. For example, a subclass might perform tracing of calls, or might trap exceptions.

Parameters:
field - The field to be retrieved
instance - The object whose field is to be retrieved. This is set to null if the field is static.
Returns:
The value of the field
Throws:
java.lang.IllegalAccessException - if the invocation throws an IllegalAccessException

convertToDotNet

public static java.lang.Object convertToDotNet(Value value,
                                               cli.System.Type targetType,
                                               XPathContext context)
                                        throws XPathException
Convert an XPath value to a .NET object

Parameters:
value - the XPath value to be converted
targetType - the target type of the .NET object
context - XPath dynamic context
Returns:
the .NET object
Throws:
XPathException

type

public static cli.System.Type type(java.lang.String name)

convertFromDotNet

public static Value convertFromDotNet(java.lang.Object result,
                                      cli.System.Type returnType,
                                      XPathContext context)