Package org.openrefine.operations

Class RowMapOperation

java.lang.Object

org.openrefine.operations.EngineDependentOperation

org.openrefine.operations.RowMapOperation

All Implemented Interfaces:

Operation

Direct Known Subclasses:

ColumnMoveOperation, ColumnRemovalOperation, ColumnRenameOperation, ColumnReorderOperation, ColumnSplitOperation, ExpressionBasedOperation, ReconClearSimilarCellsOperation, ReconCopyAcrossColumnsOperation, ReconDiscardJudgmentsOperation, ReconJudgeSimilarCellsOperation, ReconMarkNewTopicsOperation, ReconMatchBestCandidatesOperation, ReconMatchSpecificTopicOperation, ReconUseValuesAsIdentifiersOperation, RowFlagOperation, RowStarOperation

public abstract class RowMapOperation
extends EngineDependentOperation

Simplifies the architecture for immediate operations which simply act by mapping rows. This allows the mapper to be defined in a method of the operation. This class can also be subclassed by operations which ignore the engine, by initializing the engine config with EngineConfig.ALL_ROWS.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	RowMapOperation.GridMap	Stores the new column model to be applied on the new grid, and the row mappers used to derive the new grid.

Field Summary

Fields inherited from class org.openrefine.operations.EngineDependentOperation

_engineConfig

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	RowMapOperation(EngineConfig engineConfig)

Method Summary

Modifier and Type	Method	Description
ChangeResult	apply(Grid projectState, ChangeContext context)	Derives the new grid state from the current grid state.
protected RowMapOperation.GridMap	getGridMap(Grid state, ChangeContext context)	Returns the function that is applied to each row and row index, the new column model applied to the grid, and the new overlay models.
protected RowInRecordMapper	getNegativeRowMapper(Grid state, ChangeContext context)	Returns the row mapper applied to the rows not matched by the filter.
protected ColumnModel	getNewColumnModel(Grid state, ChangeContext context)	Returns the column model after the change is applied to the given grid.
protected Map<String,OverlayModel>	getNewOverlayModels(Grid state, ChangeContext context)	Returns the new overlay models after this change is applied.
protected RowInRecordMapper	getPositiveRowMapper(Grid state, ChangeContext context)	Returns the row mapper applied to the rows matched by the filter.
protected Grid	postTransform(Grid grid, ChangeContext context)	Method run at the end of the change to update any statistics (such as ReconStats or overlay models) on the resulting state.

Methods inherited from class org.openrefine.operations.EngineDependentOperation

getEngine, getEngineConfig

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.openrefine.operations.Operation

getDescription, getOperationId, isReproducible

Constructor Detail

RowMapOperation

protected RowMapOperation(EngineConfig engineConfig)

Method Detail

apply

public ChangeResult apply(Grid projectState,
                          ChangeContext context)
                   throws OperationException

Description copied from interface: Operation

Derives the new grid state from the current grid state. Executing this method should be quick (even on large datasets) since it is expected to just derive the new grid from the existing one without actually executing any expensive computation. Long-running computations should rather go in the derivation of a ChangeData which will be fetched asynchronously.

Parameters:

projectState - the state of the grid before the change

Returns:

an object which bundles up various pieces of information produced by the operation: primarily, the new grid after applying the operation. This object can be subclassed to expose more information, which should be serializable with Jackson so that it reaches the frontend.

Throws:

OperationException - when the change cannot be applied to the given grid

getGridMap

protected RowMapOperation.GridMap getGridMap(Grid state,
                                             ChangeContext context)
                                      throws OperationException

Returns the function that is applied to each row and row index, the new column model applied to the grid, and the new overlay models. Computing these in one go can be useful in certain situations, for instance when the number of columns added to the column model depends on the data. If a subclass needs to return only one non-default value out of mapper, column model and overlay models it can instead override the corresponding method.

Parameters:

state - the initial column model

Throws:

OperationException - if the change does not apply to the given grid

getNewColumnModel

protected ColumnModel getNewColumnModel(Grid state,
                                        ChangeContext context)
                                 throws OperationException

Returns the column model after the change is applied to the given grid. By default, returns the same column model.

Parameters:

state - the grid to which the change should be applied

Returns:

the column model of the new grid

Throws:

OperationException

getPositiveRowMapper

protected RowInRecordMapper getPositiveRowMapper(Grid state,
                                                 ChangeContext context)
                                          throws OperationException

Returns the row mapper applied to the rows matched by the filter.

Parameters:

state - the initial state of the grid

Throws:

OperationException

getNegativeRowMapper

protected RowInRecordMapper getNegativeRowMapper(Grid state,
                                                 ChangeContext context)
                                          throws OperationException

Returns the row mapper applied to the rows not matched by the filter.

Parameters:

state - the initial state of the grid

Throws:

OperationException

getNewOverlayModels

protected Map<String,OverlayModel> getNewOverlayModels(Grid state,
                                                             ChangeContext context)
                                                      throws OperationException

Returns the new overlay models after this change is applied.

Throws:

OperationException

postTransform

protected Grid postTransform(Grid grid,
                             ChangeContext context)
                      throws OperationException

Method run at the end of the change to update any statistics (such as ReconStats or overlay models) on the resulting state.

Parameters:

grid - the grid after the map operation

Returns:

the grid with updated column statistics (or any other post transformation)

Throws:

OperationException