adams.flow.transformer
Class TwitterFilter

java.lang.Object
  adams.core.ConsoleObject
      adams.core.option.AbstractOptionHandler
          adams.flow.core.AbstractActor
              adams.flow.transformer.AbstractTransformer
                  adams.flow.transformer.TwitterFilter

All Implemented Interfaces:

AdditionalInformationHandler, CleanUpHandler, Debuggable, DebugOutputHandler, Destroyable, OptionHandler, QuickInfoSupporter, ShallowCopySupporter<AbstractActor>, SizeOfHandler, Stoppable, VariableChangeListener, Actor, ErrorHandler, InputConsumer, OutputProducer, GrammarSupplier, Serializable, Comparable

public class TwitterFilter
extends AbstractTransformer
implements GrammarSupplier

Filters Twitter objects (tweet/status) according to the provided filter expression. Only objects that match the filter expression are passed on.

The expressions use the following grammar:

expr_list ::= expr_list expr | expr;
expr ::= ( expr )
| boolexpr
;

boolexpr ::= BOOLEAN
| ( boolexpr )
| not boolexpr
| boolexpr and boolexpr
| boolexpr or boolexpr
| boolexpr xor boolexpr

| langcode <match> pattern
| country <match> pattern
| countrycode <match> pattern
| place <match> pattern
| source <match> pattern
| text <match> pattern
| user <match> pattern

| ifelse ( boolexpr:test , boolexpr:test_true , boolexpr:test_false )
;

The '<match>' operator can be one of the following:
1. '=' - exact match (the twitter field must be the exact 'pattern' string)
2. ':' - substring match (the 'pattern' can occur anywhere in the twitter field)
3. '~' - regular expression match (the 'pattern' is a regular expression that the twitter field must match)

Please note, all strings are converted to lower case before the filter is applied.

Input/output:
- accepts:
twitter4j.Status
- generates:
twitter4j.Status

Valid options are:

-D <int> (property: debugLevel)
    The greater the number the more additional info the scheme may output to 
    the console (0 = off).
    default: 0
    minimum: 0
 

-name <java.lang.String> (property: name)
    The name of the actor.
    default: TwitterFilter
 

-annotation <adams.core.base.BaseText> (property: annotations)
    The annotations to attach to this actor.
    default: 
 

-skip (property: skip)
    If set to true, transformation is skipped and the input token is just forwarded 
    as it is.
 

-stop-flow-on-error (property: stopFlowOnError)
    If set to true, the flow gets stopped in case this actor encounters an error;
     useful for critical actors.
 

-expression <java.lang.String> (property: expression)
    The filter expression to use.
    default: text~\".*\"
 

Version:

$Revision: 7105 $

Author:

fracpete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Field Summary

protected String

m_Expression the filter expression.

Fields inherited from class adams.flow.transformer.AbstractTransformer

BACKUP_INPUT, BACKUP_OUTPUT, m_InputToken, m_OutputToken

Fields inherited from class adams.flow.core.AbstractActor

m_Annotations, m_BackupState, m_DetectedObjectVariables, m_DetectedVariables, m_ErrorHandler, m_Executed, m_Executing, m_ExecutionListeningSupporter, m_FullName, m_Headless, m_Name, m_Parent, m_Root, m_ScopeHandler, m_Self, m_Skip, m_StopFlowOnError, m_StopMessage, m_Stopped, m_StorageHandler, m_VariablesUpdated

Fields inherited from class adams.core.option.AbstractOptionHandler

m_DebugLevel, m_OptionManager

Fields inherited from interface adams.flow.core.Actor

FILE_EXTENSION, FILE_EXTENSION_GZ

Constructor Summary

TwitterFilter()

Method Summary

Class[]	accepts() Returns the class that the consumer accepts.
void	defineOptions() Adds options to the internal list of options.
protected String	doExecute() Executes the flow item.
String	expressionTipText() Returns the tip text for this property.
Class[]	generates() Returns the class of objects that it generates.
String	getExpression() Returns the separator in use.
String	getGrammar() Returns a string representation of the grammar.
String	getQuickInfo() Returns a quick info about the actor, which will be displayed in the GUI.
String	globalInfo() Returns a string describing the object.
protected HashMap	processStatus(twitter4j.Status status) Processes the specified status.
void	setExpression(String value) Sets the separator to use.

Methods inherited from class adams.flow.transformer.AbstractTransformer

backupState, execute, hasPendingOutput, input, output, postExecute, reset, restoreState, wrapUp

Methods inherited from class adams.flow.core.AbstractActor

annotationsTipText, canInspectOptions, canPerformSetUpCheck, cleanUp, compareTo, debug, destroy, equals, findVariables, findVariables, findVariables, forceVariables, forCommandLine, forName, getAdditionalInformation, getAnnotations, getDefaultName, getDetectedVariables, getErrorHandler, getFlowActors, getFlowExecutionListeningSupporter, getFullName, getName, getNextSibling, getParent, getParentComponent, getPreviousSibling, getRoot, getScopeHandler, getSkip, getStopFlowOnError, getStopMessage, getStorageHandler, getVariables, handleError, handleException, hasErrorHandler, hasStopMessage, index, initialize, isBackedUp, isExecuted, isExecuting, isFinished, isHeadless, isStopped, nameTipText, performSetUpChecks, preExecute, pruneBackup, pruneBackup, setAnnotations, setErrorHandler, setHeadless, setName, setParent, setSkip, setStopFlowOnError, setUp, setVariables, shallowCopy, shallowCopy, sizeOf, skipTipText, stopExecution, stopExecution, stopFlowOnErrorTipText, updateDetectedVariables, updatePrefix, updateVariables, variableChanged

Methods inherited from class adams.core.option.AbstractOptionHandler

cleanUpOptions, debug, debugLevelTipText, finishInit, getDebugLevel, getOptionManager, isDebugOn, newOptionManager, setDebugLevel, toCommandLine, toString

Methods inherited from class adams.core.ConsoleObject

getDebugging, getSystemErr, getSystemOut

Methods inherited from class java.lang.Object

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

Methods inherited from interface adams.flow.core.Actor

cleanUp, compareTo, debug, destroy, equals, findVariables, getAnnotations, getDefaultName, getDetectedVariables, getErrorHandler, getFlowExecutionListeningSupporter, getFullName, getName, getNextSibling, getParent, getParentComponent, getPreviousSibling, getRoot, getScopeHandler, getSkip, getStopFlowOnError, getStopMessage, getStorageHandler, getVariables, handleError, hasErrorHandler, hasStopMessage, index, isExecuted, isFinished, isHeadless, isStopped, setAnnotations, setErrorHandler, setHeadless, setName, setParent, setSkip, setStopFlowOnError, setUp, setVariables, sizeOf, stopExecution, stopExecution, variableChanged

Methods inherited from interface adams.core.AdditionalInformationHandler

getAdditionalInformation

Methods inherited from interface adams.core.option.OptionHandler

cleanUpOptions, getOptionManager

Field Detail

m_Expression

protected String m_Expression

the filter expression.

Constructor Detail

TwitterFilter

public TwitterFilter()

Method Detail

globalInfo

public String globalInfo()

Returns a string describing the object.

Specified by:

globalInfo in class AbstractOptionHandler

Returns:

a description suitable for displaying in the gui

getGrammar

public String getGrammar()

Returns a string representation of the grammar.

Specified by:

getGrammar in interface GrammarSupplier

Returns:

the grammar, null if not available

defineOptions

public void defineOptions()

Adds options to the internal list of options.

Specified by:

defineOptions in interface OptionHandler

Overrides:

defineOptions in class AbstractActor

setExpression

public void setExpression(String value)

Sets the separator to use. \t, \n, \r, \\ must be quoted.

Parameters:

value - the separator

getExpression

public String getExpression()

Returns the separator in use. \t, \r, \n, \\ get returned quoted.

Returns:

the separator

expressionTipText

public String expressionTipText()

Returns the tip text for this property.

Returns:

tip text for this property suitable for displaying in the GUI or for listing the options.

getQuickInfo

public String getQuickInfo()

Returns a quick info about the actor, which will be displayed in the GUI.

Specified by:

getQuickInfo in interface QuickInfoSupporter

Specified by:

getQuickInfo in interface Actor

Overrides:

getQuickInfo in class AbstractActor

Returns:

null if no info available, otherwise short string

accepts

public Class[] accepts()

Returns the class that the consumer accepts.

Specified by:

accepts in interface InputConsumer

Returns:

twitter4j.Status.class

generates

public Class[] generates()

Returns the class of objects that it generates.

Specified by:

generates in interface OutputProducer

Returns:

twitter4j.Status.class

processStatus

protected HashMap processStatus(twitter4j.Status status)

Processes the specified status.

Parameters:

status - the status to process

Returns:

the association between fields and status values

doExecute

protected String doExecute()

Executes the flow item.

Specified by:

doExecute in class AbstractActor

Returns:

null if everything is fine, otherwise error message