org.pentaho.reporting.engine.classic.core.states
Class DataRowConnector

java.lang.Object
  org.pentaho.reporting.engine.classic.core.states.DataRowConnector

All Implemented Interfaces:

DataRow

public final class DataRowConnector
extends Object
implements DataRow

This is the connection-proxy to the various data sources contained in the elements. During report processing the report states get cloned while the elements remain uncloned. The DataRowConnector connects the DataRowBackend (which contains the data) with the stateless elements.

Author:

Thomas Morgner

Constructor Summary

DataRowConnector()
Default constructor.

Method Summary

Object	get(String col) Returns the value of the column, function or expression using its name.
String[]	getColumnNames() Returns the known column names, this data-row understands.
DataRow	getDataRowBackend() Returns the assigned data row backend.
static DataSource	getLastDatasource(DataTarget e) Deprecated. no longer used.
boolean	isChanged(String name) Checks whether the value contained in the column has changed since the last advance-operation.
void	setDataRowBackend(DataRow dataRow) Sets the data row backend for this DataRowConnector.
String	toString() Returns a string describing the object.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataRowConnector

public DataRowConnector()

Default constructor.

Method Detail

getDataRowBackend

public DataRow getDataRowBackend()

Returns the assigned data row backend.

Returns:

the currently assigned DataRowBackend for this DataRowConnector.

getColumnNames

public String[] getColumnNames()

Description copied from interface: DataRow

Returns the known column names, this data-row understands. The column names may change over time but do not change while a event is processed by a function. The array returned is a copy of the internal data-storage and can be safely modified.

Specified by:

getColumnNames in interface DataRow

Returns:

the column names as array.

setDataRowBackend

public void setDataRowBackend(DataRow dataRow)

Sets the data row backend for this DataRowConnector. The backend actually contains the data which will be queried, while this DataRowConnector is simply a proxy forwarding all requests to the backend.

Parameters:

dataRow - the data row backend

get

public Object get(String col)

Returns the value of the column, function or expression using its name.

Specified by:

get in interface DataRow

Parameters:

col - the column, function or expression index.

Returns:

The column, function or expression value.

Throws:

IllegalStateException - if there is no backend connected

getLastDatasource

public static DataSource getLastDatasource(DataTarget e)

Deprecated. no longer used.

Queries the last datasource in the chain of targets and filters.

The last datasource is used to feed data into the data processing chain. The result of this computation is retrieved by the element using the registered datasource to query the queue.

Parameters:

e - the data target.

Returns:

The last DataSource in the chain.

toString

public String toString()

Returns a string describing the object.

Overrides:

toString in class Object

Returns:

The string.

isChanged

public boolean isChanged(String name)

Description copied from interface: DataRow

Checks whether the value contained in the column has changed since the last advance-operation.

Specified by:

isChanged in interface DataRow

Parameters:

name - the name of the column.

Returns:

true, if the value has changed, false otherwise.