Package org.openrefine.grel

Class GrelEvaluable

java.lang.Object

org.openrefine.grel.GrelEvaluable

All Implemented Interfaces:

Serializable, Evaluable

public class GrelEvaluable
extends Object
implements Evaluable

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
GrelEvaluable(GrelExpr expr, String languagePrefix)

Method Summary

Modifier and Type	Method	Description
Object	evaluate(Properties bindings)	Evaluate this expression in the given environment (bindings).
Set<String>	getColumnDependencies(String baseColumn)	Returns the names of the columns this expression depends on.
String	getLanguagePrefix()
String	getSource()	Returns the source string which generated this expression.
boolean	isLocal()
Evaluable	renameColumnDependencies(Map<String,String> substitutions)	Translates this expression by simultaneously substituting column names as the supplied map specifies.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.openrefine.expr.Evaluable

getFullSource

Constructor Detail

GrelEvaluable

public GrelEvaluable(GrelExpr expr,
                     String languagePrefix)

Method Detail

evaluate

public Object evaluate(Properties bindings)

Description copied from interface: Evaluable

Evaluate this expression in the given environment (bindings).

Specified by:

evaluate in interface Evaluable

getColumnDependencies

public Set<String> getColumnDependencies(String baseColumn)

Description copied from interface: Evaluable

Returns the names of the columns this expression depends on.

Specified by:

getColumnDependencies in interface Evaluable

Parameters:

baseColumn - the name of the column this expression is based on (null if none)

Returns:

null if the columns could not be isolated: in this case, the expression might depend on all columns in the project.

renameColumnDependencies

public Evaluable renameColumnDependencies(Map<String,String> substitutions)

Description copied from interface: Evaluable

Translates this expression by simultaneously substituting column names as the supplied map specifies.

This is only possible if the extraction of column dependencies with Evaluable.getColumnDependencies(String) succeeds (return a non-null value).

Specified by:

renameColumnDependencies in interface Evaluable

Parameters:

substitutions - a map specifying new names for some columns. If a column name is not present in the map, it is assumed that the column is not renamed.

Returns:

a new expression with updated column names.

getSource

public String getSource()

Description copied from interface: Evaluable

Returns the source string which generated this expression. This does not include the language prefix, which can be obtained by Evaluable.getLanguagePrefix().

Specified by:

getSource in interface Evaluable

getLanguagePrefix

public String getLanguagePrefix()

Specified by:

getLanguagePrefix in interface Evaluable

Returns:

the language prefix used to generate this evaluable.

isLocal

public boolean isLocal()

Specified by:

isLocal in interface Evaluable

Returns:

true when the evaluable can be computed fully (and quickly) from the local context (the given row or record). If it relies on any other information (external web service, aggregation over the project), then it should return false, indicating that the return value may need to be cached by the caller.