Package org.openrefine.wikidata.schema

Class WbVariableExpr<T>

java.lang.Object

org.openrefine.wikidata.schema.WbVariableExpr<T>

Type Parameters:

T - the type of Wikibase value returned by the expression.

All Implemented Interfaces:

WbExpression<T>

Direct Known Subclasses:

WbDateVariable, WbEntityVariable, WbItemVariable, WbLanguageVariable, WbLocationVariable, WbStringVariable

public abstract class WbVariableExpr<T>
extends Object
implements WbExpression<T>

A base class for expressions which draw their values from a particular column.

Author:

Antonin Delpeuch

Constructor Summary

Constructors

Constructor	Description
WbVariableExpr()	Constructs a variable without setting the column name yet.

Method Summary

Modifier and Type	Method	Description
protected boolean	equalAsVariables(Object other, Class<? extends WbVariableExpr<?>> targetClass)	Helper for equality methods of subclasses.
T	evaluate(ExpressionContext ctxt)	Evaluates the expression in a given context, returning
abstract T	fromCell(Cell cell, ExpressionContext ctxt)	Method that should be implemented by subclasses, converting an OpenRefine cell to a Wikibase value.
String	getColumnName()	Returns the column name used by the variable.
int	hashCode()
void	setColumnName(String columnName)	Changes the column name used by the variable.

Methods inherited from class java.lang.Object

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

Constructor Details

WbVariableExpr

public WbVariableExpr()

Constructs a variable without setting the column name yet.

Method Details

getColumnName

public String getColumnName()

Returns the column name used by the variable.

Returns:

the OpenRefine column name

setColumnName

public void setColumnName(String columnName)

Changes the column name used by the variable. This is useful for deserialization, as well as updates when column names change.

evaluate

public T evaluate(ExpressionContext ctxt)
           throws SkipSchemaExpressionException,
QAWarningException

Evaluates the expression in a given context, returning

Specified by:

evaluate in interface WbExpression<T>

Throws:

QAWarningException

SkipSchemaExpressionException

fromCell

public abstract T fromCell(Cell cell,
 ExpressionContext ctxt)
                    throws SkipSchemaExpressionException,
QAWarningException

Method that should be implemented by subclasses, converting an OpenRefine cell to a Wikibase value. Access to other values and emitting warnings is possible via the supplied EvaluationContext object.

Parameters:

cell - the cell to convert

ctxt - the evaluation context

Returns:

the corresponding Wikibase value

Throws:

SkipSchemaExpressionException

QAWarningException

equalAsVariables

protected boolean equalAsVariables(Object other,
 Class<? extends WbVariableExpr<?>> targetClass)

Helper for equality methods of subclasses.

Parameters:

other - the object to compare

columnName - the column name to compare to

targetClass - the target class for equality

Returns:

hashCode

public int hashCode()

Overrides:

hashCode in class Object