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:

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
final void	build(String uri, ExprList args)	Called during query plan construction immediately after the construction of the extension instance.
abstract void	checkBuild(String uri, ExprList args)
static List<NodeValue>	evalArgs(Binding binding, ExprList args, FunctionEnv env)
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)	Test a list of values - argument will not be null but may have the wrong number of arguments.

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 final void build(String uri,
 ExprList args)

Description copied from interface: Function

Called during query plan construction immediately after the construction of the extension instance. Can throw ExprBuildException if something is wrong (like wrong number of arguments).

Specified by:

build in interface Function

args - The parsed arguments

exec

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

Description copied from interface: Function

Test a list of values - argument will not be null but may have the wrong number of arguments. FunctionBase provides a more convenient way to implement a function. Can throw ExprEvalsException 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

evalArgs

public static List<NodeValue> evalArgs(Binding binding,
 ExprList args,
 FunctionEnv env)

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)