Package com.inductiveautomation.ignition.common.expressions.functions

Class TagFunction

java.lang.Object

com.inductiveautomation.ignition.common.expressions.functions.BaseFunction

com.inductiveautomation.ignition.common.expressions.functions.AbstractFunction

com.inductiveautomation.ignition.common.expressions.functions.TagFunction

All Implemented Interfaces:

Function, TagChangeListener, EventListener

public class TagFunction
extends AbstractFunction
implements TagChangeListener

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	TagFunction.EvaluationMode

Constructor Summary

Constructors

Constructor	Description
TagFunction()
TagFunction(boolean useReads)	Create a tag function that can use reads instead of subscribing.
TagFunction(TagFunction.EvaluationMode mode)

Method Summary

Modifier and Type	Method	Description
void	connect(CommonContext context, InteractionListener updateListener)	Empty implementation from BaseFunction.
Function	copy()	Returns this.
void	disconnect()	Empty implementation from BaseFunction.
QualifiedValue	execute(Expression[] args)	Execute this function, and return the function's qualified value.
protected void	executeRead()
protected void	fireInteractionListener()
String	getArgDocString()	Returns a string to be used in the auto-generated function documentation.
protected String	getFunctionDisplayName()
SecurityContext	getSecurityContext()
Class<?>	getType()	Returns the type that this function will return upon execution
Object	getValue()
void	setType(Class<?> type)
void	setValue(Object value)
void	shutdown()	Empty implementation from BaseFunction.
void	startup()	Empty implementation from BaseFunction.
void	tagChanged(TagChangeEvent e)	Invoked when the tag has changed
protected void	updatePath(TagPath path)
protected void	updateValueSynched(QualifiedValue value)
protected boolean	validateNumArgs(int num)

Methods inherited from class com.inductiveautomation.ignition.common.expressions.functions.AbstractFunction

executeArg, initArgs, log

Methods inherited from class com.inductiveautomation.ignition.common.expressions.functions.BaseFunction

executeAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.inductiveautomation.ignition.common.tags.model.event.TagChangeListener

isLightweight

Constructor Details

TagFunction

public TagFunction()

TagFunction

public TagFunction(boolean useReads)

Create a tag function that can use reads instead of subscribing. If false, it will use Subscribed_ReadInitial, due to changes that were made in the 8.0 line, which introduced that semantic. If that is not desired, the more specific constructor that tags EvaluationMode should be used.

TagFunction

public TagFunction(TagFunction.EvaluationMode mode)

Method Details

executeRead

protected void executeRead()
                    throws ExpressionException

Throws:

ExpressionException

updatePath

protected void updatePath(TagPath path)
                   throws Exception

Throws:

Exception

execute

public QualifiedValue execute(Expression[] args)
                       throws ExpressionException

Description copied from interface: Function

Execute this function, and return the function's qualified value.

Specified by:

execute in interface Function

Throws:

ExpressionException

validateNumArgs

protected boolean validateNumArgs(int num)

Overrides:

validateNumArgs in class AbstractFunction

copy

public Function copy()

Description copied from class: BaseFunction

Returns this. Override to create a clone if you need a unique function object per Expression.

Specified by:

copy in interface Function

Overrides:

copy in class BaseFunction

connect

public void connect(CommonContext context,
 InteractionListener updateListener)

Description copied from class: BaseFunction

Empty implementation from BaseFunction. Override if necessary.

Specified by:

connect in interface Function

Overrides:

connect in class BaseFunction

disconnect

public void disconnect()

Description copied from class: BaseFunction

Empty implementation from BaseFunction. Override if necessary.

Specified by:

disconnect in interface Function

Overrides:

disconnect in class BaseFunction

shutdown

public void shutdown()

Description copied from class: BaseFunction

Empty implementation from BaseFunction. Override if necessary.

Specified by:

shutdown in interface Function

Overrides:

shutdown in class BaseFunction

startup

public void startup()

Description copied from class: BaseFunction

Empty implementation from BaseFunction. Override if necessary.

Specified by:

startup in interface Function

Overrides:

startup in class BaseFunction

getArgDocString

public String getArgDocString()

Description copied from interface: Function

Returns a string to be used in the auto-generated function documentation. The string should represent the arguments for the function, such as "string, count" for the "repeat" function.

Specified by:

getArgDocString in interface Function

getType

public Class<?> getType()

Description copied from interface: Function

Returns the type that this function will return upon execution

Specified by:

getType in interface Function

setType

public void setType(Class<?> type)

getSecurityContext

public SecurityContext getSecurityContext()

Specified by:

getSecurityContext in interface TagChangeListener

Returns:

the SecurityContext associated with this TagChangeListener

tagChanged

public void tagChanged(TagChangeEvent e)

Description copied from interface: TagChangeListener

Invoked when the tag has changed

Specified by:

tagChanged in interface TagChangeListener

Parameters:

e - a ChangeEvent object

updateValueSynched

protected void updateValueSynched(QualifiedValue value)

fireInteractionListener

protected void fireInteractionListener()

getValue

public Object getValue()

setValue

public void setValue(Object value)

getFunctionDisplayName

protected String getFunctionDisplayName()

Specified by:

getFunctionDisplayName in class AbstractFunction