Module org.apache.jena.arq

Package org.apache.jena.sparql.function

Class FunctionBase

java.lang.Object

org.apache.jena.sparql.function.FunctionBase

All Implemented Interfaces:

Function

Direct Known Subclasses:

AFN_AdjustToTimezone, cartesian, context, execTime, FN_AdjustDatetimeToTimezone, FN_AdjustDateToTimezone, FN_AdjustTimeToTimezone, FN_Apply, FN_Error, FN_FormatNumber, FN_Round, FN_Round_Half_Even, FN_StrConcat, FN_StrNormalizeUnicode, FN_StrReplace, FN_StrSubstring, FunctionBase0, FunctionBase1, FunctionBase2, FunctionBase3, FunctionBase4, FunctionBase5, log, rnd, ScriptFunction, sprintf, strjoin, substring

public abstract class FunctionBase
extends Object
implements Function

Implementation root for custom function evaluation.

Constructor Summary

Constructors

Constructor	Description
FunctionBase()

Method Summary

Modifier and Type	Method	Description
void	build(String uri, ExprList args, Context context)	Called during query plan construction immediately after the construction of the extension instance.
abstract void	checkBuild(String uri, ExprList args)
abstract NodeValue	exec(List<NodeValue> args)	Function call to a list of evaluated argument values
NodeValue	exec(Binding binding, ExprList args, String uri, FunctionEnv env)	Call a function.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

FunctionBase

public FunctionBase()

Method Details

build

public void build(String uri,
 ExprList args,
 Context context)

Description copied from interface: Function

Called during query plan construction immediately after the construction of the extension instance. A function can throw ExprException if something is wrong (like wrong number of arguments).

Specified by:

build in interface Function

Parameters:

uri - The function URI

args - The parsed arguments

context - The build context.

exec

public NodeValue exec(Binding binding,
 ExprList args,
 String uri,
 FunctionEnv env)

Description copied from interface: Function

Call a function. The argument list will not be null but may have the wrong number of arguments. FunctionBase provides a more convenient way to implement a function. Functions can throw ExprEvalException if something goes wrong.

Specified by:

exec in interface Function

Parameters:

binding - The current solution

args - A list of unevaluated expressions

uri - The name of this

env - The execution context

Returns:

NodeValue - a value

exec

public abstract NodeValue exec(List<NodeValue> args)

Function call to a list of evaluated argument values

checkBuild

public abstract void checkBuild(String uri,
 ExprList args)