Package com.inductiveautomation.ignition.common.expressions

Class ConstantExpression

java.lang.Object

com.inductiveautomation.ignition.common.expressions.ConstantExpression

All Implemented Interfaces:

Expression

public class ConstantExpression
extends java.lang.Object
implements Expression

Constructor Summary

Constructors

Constructor	Description
ConstantExpression()
ConstantExpression(java.lang.Object value)
ConstantExpression(java.lang.Object value, QualityCode quality)

Method Summary

Modifier and Type	Method	Description
void	connect(CommonContext context, InteractionListener updateListener)	Gives the expression a chance to connect itself to things, if necessary.
void	disconnect()	Tells the expression to disconnect from anything it was connected to.
QualifiedValue	execute()	Compute and return the value of this expression
Expression[]	getChildren()	The children (if any) that this expression is dependent on for its execution
java.lang.String	getOpName()	Return a human-readable name for the operation that this expression performs
QualityCode	getQuality()
java.lang.Class<?>	getType()	Return the type that this expression will return
java.lang.Object	getValue()
void	setQuality(QualityCode quality)
void	setValue(java.lang.Object object)
void	shutdown()	Tells the expression to shutdown any polling operations.
void	startup()	Tells the expression to startup any polling operations.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstantExpression

public ConstantExpression(java.lang.Object value)

ConstantExpression

public ConstantExpression(java.lang.Object value,
                          QualityCode quality)

ConstantExpression

public ConstantExpression()

Method Detail

execute

@Nonnull
public QualifiedValue execute()

Description copied from interface: Expression

Compute and return the value of this expression

Specified by:

execute in interface Expression

getType

public java.lang.Class<?> getType()

Description copied from interface: Expression

Return the type that this expression will return

Specified by:

getType in interface Expression

getOpName

public java.lang.String getOpName()

Description copied from interface: Expression

Return a human-readable name for the operation that this expression performs

Specified by:

getOpName in interface Expression

getChildren

public Expression[] getChildren()

Description copied from interface: Expression

The children (if any) that this expression is dependent on for its execution

Specified by:

getChildren in interface Expression

getValue

public java.lang.Object getValue()

setValue

public void setValue(java.lang.Object object)

getQuality

public QualityCode getQuality()

setQuality

public void setQuality(QualityCode quality)

connect

public void connect(CommonContext context,
                    InteractionListener updateListener)

Description copied from interface: Expression

Gives the expression a chance to connect itself to things, if necessary. Most expressions do not have any connections. An expression should notify the updateListener if they change.

Specified by:

connect in interface Expression

disconnect

public void disconnect()

Description copied from interface: Expression

Tells the expression to disconnect from anything it was connected to.

Specified by:

disconnect in interface Expression

shutdown

public void shutdown()

Description copied from interface: Expression

Tells the expression to shutdown any polling operations.

Specified by:

shutdown in interface Expression

startup

public void startup()

Description copied from interface: Expression

Tells the expression to startup any polling operations. Expressions that use this can remember the updateListener from connect() to feed update notification to.

Specified by:

startup in interface Expression