org.knime.base.node.io.filereader
Class FileReaderNodeModel

java.lang.Object
  extended by org.knime.core.node.NodeModel
      extended by org.knime.base.node.io.filereader.FileReaderNodeModel

public class FileReaderNodeModel
extends NodeModel

Author:
Peter Ohl, University of Konstanz

Field Summary
static String FILEREADER_HISTORY_ID
          The id this objects uses to store its file history in the StringHistory object.
 
Constructor Summary
FileReaderNodeModel()
          Creates a new model that creates and holds a Filetable.
FileReaderNodeModel(String filename)
          Creates a new model and either read its settings from the specified file, if the filename ends with ".xml", or set the specified file name as default data file name for the configuration dialog.
 
Method Summary
protected  DataTableSpec[] configure(DataTableSpec[] inSpecs)
          This function is called whenever the derived model should re-configure its output DataTableSpecs.
protected  BufferedDataTable[] execute(BufferedDataTable[] data, ExecutionContext exec)
          This function is invoked by the Node#executeNode() method of the node (through the #executeModel(BufferedDataTable[],ExecutionMonitor) method)only after all predecessor nodes have been successfully executed and all data is therefore available at the input ports.
(package private) static String[] getFileHistory()
           
(package private)  FileReaderSettings getFileReaderSettings()
           
protected  void loadInternals(File nodeInternDir, ExecutionMonitor exec)
          Load internals into the derived NodeModel.
protected  void loadValidatedSettingsFrom(NodeSettingsRO settings)
          Reads in all user settings of the model.
protected  void reset()
          Override this function in the derived model and reset your NodeModel.
protected  void saveInternals(File nodeInternDir, ExecutionMonitor exec)
          Save internals of the derived NodeModel.
protected  void saveSettingsTo(NodeSettingsWO settings)
          Writes the current user settings into a configuration object.
protected  void validateSettings(NodeSettingsRO settings)
          Checks all user settings in the specified spec object.
 
Methods inherited from class org.knime.core.node.NodeModel
addWarningListener, configure, continueLoop, execute, executeModel, getInHiLiteHandler, getLoopEndNode, getLoopStartNode, getNrInPorts, getNrOutPorts, getOutHiLiteHandler, getWarningMessage, notifyViews, notifyWarningListeners, peekFlowVariableDouble, peekFlowVariableInt, peekFlowVariableString, peekScopeVariableDouble, peekScopeVariableInt, peekScopeVariableString, pushFlowVariableDouble, pushFlowVariableInt, pushFlowVariableString, pushScopeVariableDouble, pushScopeVariableInt, pushScopeVariableString, removeWarningListener, setInHiLiteHandler, setWarningMessage, stateChanged
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

FILEREADER_HISTORY_ID

public static final String FILEREADER_HISTORY_ID
The id this objects uses to store its file history in the StringHistory object. Don't reuse this id unless you want to share the history list.

See Also:
Constant Field Values
Constructor Detail

FileReaderNodeModel

public FileReaderNodeModel()
Creates a new model that creates and holds a Filetable.


FileReaderNodeModel

public FileReaderNodeModel(String filename)
Creates a new model and either read its settings from the specified file, if the filename ends with ".xml", or set the specified file name as default data file name for the configuration dialog. Settings in the model resulting from this constructor must not necessarily be correct or valid.

Parameters:
filename - valid URL to a data file or a XML configuration file. If the filename ends with ".xml" it's considered a xml file spec.
Method Detail

reset

protected void reset()
Override this function in the derived model and reset your NodeModel. All components should unregister themselves from any observables (at least from the hilite handler right now). All internally stored data structures should be released. User settings should not be deleted/reset though.

Specified by:
reset in class NodeModel

execute

protected BufferedDataTable[] execute(BufferedDataTable[] data,
                                      ExecutionContext exec)
                               throws CanceledExecutionException,
                                      InvalidSettingsException
This function is invoked by the Node#executeNode() method of the node (through the #executeModel(BufferedDataTable[],ExecutionMonitor) method)only after all predecessor nodes have been successfully executed and all data is therefore available at the input ports. Implement this function with your task in the derived model.

The input data is available in the given array argument inData and is ensured to be neither null nor contain null elements.

In order to create output data, you need to create objects of class BufferedDataTable. Use the execution context argument to create BufferedDataTable.

Overrides:
execute in class NodeModel
Parameters:
data - An array holding DataTable elements, one for each input.
exec - The execution monitor for this execute method. It provides us with means to create new BufferedDataTable. Additionally, it should be asked frequently if the execution should be interrupted and throws an exception then. This exception might me caught, and then after closing all data streams, been thrown again. Also, if you can tell the progress of your task, just set it in this monitor.
Returns:
An array of non- null DataTable elements with the size of the number of outputs. The result of this execution.
Throws:
CanceledExecutionException
InvalidSettingsException

getFileReaderSettings

FileReaderSettings getFileReaderSettings()
Returns:
the current settings for the file reader. Could be null.

configure

protected DataTableSpec[] configure(DataTableSpec[] inSpecs)
                             throws InvalidSettingsException
This function is called whenever the derived model should re-configure its output DataTableSpecs. Based on the given input data table spec(s) and the current model's settings, the derived model has to calculate the output data table spec and return them.

The passed DataTableSpec elements are never null but can be empty. The model may return null data table spec(s) for the outputs. But still, the model may be in an executable state. Note, after the model has been executed this function will not be called anymore, as the output DataTableSpecs are then being pulled from the output DataTables. A derived NodeModel that cannot provide any DataTableSpecs at its outputs before execution (because the table structure is unknown at this point) can return an array containing just null elements.

Implementation note: This method is called from the NodeModel.configure(PortObjectSpec[]) method unless that method is overwritten.

Overrides:
configure in class NodeModel
Parameters:
inSpecs - An array of DataTableSpecs (as many as this model has inputs). Do NOT modify the contents of this array. None of the DataTableSpecs in the array can be null but empty. If the predecessor node is not yet connected, or doesn't provide a DataTableSpecs at its output port.
Returns:
An array of DataTableSpecs (as many as this model has outputs) They will be propagated to connected successor nodes. null DataTableSpec elements are changed to empty once.
Throws:
InvalidSettingsException - if the #configure() failed, that is, the settings are inconsistent with given DataTableSpec elements.

loadValidatedSettingsFrom

protected void loadValidatedSettingsFrom(NodeSettingsRO settings)
                                  throws InvalidSettingsException
Reads in all user settings of the model. If they are incomplete, inconsistent, or in any way invalid it will throw an exception.

Specified by:
loadValidatedSettingsFrom in class NodeModel
Parameters:
settings - the object to read the user settings from. Must not be null and must be validated with the validate method below.
Throws:
InvalidSettingsException - if the settings are incorrect - which should not happen as they are supposed to be validated before.
See Also:
NodeModel.loadValidatedSettingsFrom(NodeSettingsRO), NodeModel.validateSettings(NodeSettingsRO)

saveSettingsTo

protected void saveSettingsTo(NodeSettingsWO settings)
Writes the current user settings into a configuration object. Adds to the given NodeSettings the model specific settings. The settings don't need to be complete or consistent. If, right after startup, no valid settings are available this method can write either nothing or invalid settings.

Method is called by the Node if the current settings need to be saved or transfered to the node's dialog.

Specified by:
saveSettingsTo in class NodeModel
Parameters:
settings - The object to write settings into.
See Also:
NodeModel.loadValidatedSettingsFrom(NodeSettingsRO), NodeModel.validateSettings(NodeSettingsRO)

validateSettings

protected void validateSettings(NodeSettingsRO settings)
                         throws InvalidSettingsException
Checks all user settings in the specified spec object. If they are incomplete, inconsistent, or in any way invalid it will throw an exception.

Specified by:
validateSettings in class NodeModel
Parameters:
settings - the object to read the user settings from. Must not be null.
Throws:
InvalidSettingsException - if the settings in the specified object are incomplete, inconsistent, or in any way invalid.
See Also:
NodeModel.validateSettings(NodeSettingsRO)

loadInternals

protected void loadInternals(File nodeInternDir,
                             ExecutionMonitor exec)
                      throws IOException,
                             CanceledExecutionException
Load internals into the derived NodeModel. This method is only called if the Node was executed. Read all your internal structures from the given file directory to create your internal data structure which is necessary to provide all node functionalities after the workflow is loaded, e.g. view content and/or hilite mapping.

Specified by:
loadInternals in class NodeModel
Parameters:
nodeInternDir - The directory to read from.
exec - Used to report progress and to cancel the load process.
Throws:
IOException - If an error occurs during reading from this dir.
CanceledExecutionException - If the loading has been canceled.
See Also:
NodeModel.saveInternals(File,ExecutionMonitor)

saveInternals

protected void saveInternals(File nodeInternDir,
                             ExecutionMonitor exec)
                      throws IOException,
                             CanceledExecutionException
Save internals of the derived NodeModel. This method is only called if the Node is executed. Write all your internal structures into the given file directory which are necessary to recreate this model when the workflow is loaded, e.g. view content and/or hilite mapping.

Specified by:
saveInternals in class NodeModel
Parameters:
nodeInternDir - The directory to write into.
exec - Used to report progress and to cancel the save process.
Throws:
IOException - If an error occurs during writing to this dir.
CanceledExecutionException - If the saving has been canceled.
See Also:
NodeModel.loadInternals(File,ExecutionMonitor)

getFileHistory

static String[] getFileHistory()
Returns:
the current file history associated with the file reader


Copyright, 2003 - 2010. All rights reserved.
University of Konstanz, Germany.
Chair for Bioinformatics and Information Mining, Prof. Dr. Michael R. Berthold.
You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, display, or in any way exploit any of the content, in whole or in part, except as otherwise expressly permitted in writing by the copyright owner or as specified in the license file distributed with this product.