Interface Function
- All Known Implementing Classes:
 AbstractFunction,AbstractPollingFunction,AlarmBasedFunctionFactory.AlarmStateFunction,BaseFunction,ClientDynamicDispatchFunction,ClientFunctionFactory.HasRoleFunctionClient,ClientFunctionFactory.IsAlarmActiveFilteredFunctionClient,ClientFunctionFactory.IsAlarmActiveFunctionClient,ClientFunctionFactory.TranslateFunction,ComponentRunScriptExpression,DBFunctions.DatasetValueFunction,DBFunctions.DBExecFunction,DBFunctions.DBFunction,DBFunctions.IsDBConnectionAvailableFunction,DefaultFunctionFactory.AddDaysFunction,DefaultFunctionFactory.AddHoursFunction,DefaultFunctionFactory.AddMillisFunction,DefaultFunctionFactory.AddMinutesFunction,DefaultFunctionFactory.AddMonthsFunction,DefaultFunctionFactory.AddSecondsFunction,DefaultFunctionFactory.AddTimeFunction,DefaultFunctionFactory.AddWeeksFunction,DefaultFunctionFactory.AddYearsFunction,DefaultFunctionFactory.AggregateConcatFunction,DefaultFunctionFactory.BinaryEncFunction,DefaultFunctionFactory.BinaryEnumFunction,DefaultFunctionFactory.CaseFunction,DefaultFunctionFactory.CastFunction,DefaultFunctionFactory.CharFunction,DefaultFunctionFactory.CoalesceFunction,DefaultFunctionFactory.ColorChanger,DefaultFunctionFactory.ColumnRearrangeFunction,DefaultFunctionFactory.ColumnRenameFunction,DefaultFunctionFactory.ConcatFunction,DefaultFunctionFactory.CreateColorFunction,DefaultFunctionFactory.DataSetAggregateFunction,DefaultFunctionFactory.DataSetDateAggregateFunction,DefaultFunctionFactory.DateArithmeticFunction,DefaultFunctionFactory.DateDiffFunction,DefaultFunctionFactory.DateExtractFunction,DefaultFunctionFactory.DateFormatFunction,DefaultFunctionFactory.DateIsAfterFunction,DefaultFunctionFactory.DateIsBeforeFunction,DefaultFunctionFactory.DateIsBetweenFunction,DefaultFunctionFactory.DateIsDaylightTimeFunction,DefaultFunctionFactory.DaysBetweenFunction,DefaultFunctionFactory.EscapeSQL,DefaultFunctionFactory.EscapeXML,DefaultFunctionFactory.ForceQualityFunction,DefaultFunctionFactory.FromBinaryFunction,DefaultFunctionFactory.FromHexFunction,DefaultFunctionFactory.FromMillisFunction,DefaultFunctionFactory.FromOctalFunction,DefaultFunctionFactory.GetAMorPMFunction,DefaultFunctionFactory.GetBitFunction,DefaultFunctionFactory.GetDateFunction,DefaultFunctionFactory.GetDatePartFunction,DefaultFunctionFactory.GetDayOfMonthFunction,DefaultFunctionFactory.GetDayOfWeekFunction,DefaultFunctionFactory.GetDayOfYearFunction,DefaultFunctionFactory.GetHour12Function,DefaultFunctionFactory.GetHour24Function,DefaultFunctionFactory.GetMillisFunction,DefaultFunctionFactory.GetMinuteFunction,DefaultFunctionFactory.GetMonthFunction,DefaultFunctionFactory.GetQuarterFunction,DefaultFunctionFactory.GetSecondFunction,DefaultFunctionFactory.GetTimezoneFunction,DefaultFunctionFactory.GetTimezoneOffsetFunction,DefaultFunctionFactory.GetTimezoneRawOffsetFunction,DefaultFunctionFactory.GetYearFunction,DefaultFunctionFactory.GradientFunction,DefaultFunctionFactory.HoursBetweenFunction,DefaultFunctionFactory.IfFunction,DefaultFunctionFactory.IndexOfFunction,DefaultFunctionFactory.IsGoodFunction,DefaultFunctionFactory.IsNullFunction,DefaultFunctionFactory.IsQualityFunction,DefaultFunctionFactory.LeftOrRightFunction,DefaultFunctionFactory.LengthFunction,DefaultFunctionFactory.LookupFunction,DefaultFunctionFactory.MidnightFunction,DefaultFunctionFactory.MillisBetweenFunction,DefaultFunctionFactory.MinutesBetweenFunction,DefaultFunctionFactory.MonthsBetweenFunction,DefaultFunctionFactory.NowFunction,DefaultFunctionFactory.NumberFormatFunction,DefaultFunctionFactory.OrdinalFunction,DefaultFunctionFactory.PowerFunction,DefaultFunctionFactory.QualifiedValueFunction,DefaultFunctionFactory.QualityOfFunction,DefaultFunctionFactory.RepeatFunction,DefaultFunctionFactory.ReplaceFunction,DefaultFunctionFactory.RoundFunction,DefaultFunctionFactory.SecondsBetweenFunction,DefaultFunctionFactory.SequenceFunction,DefaultFunctionFactory.SetTimeFunction,DefaultFunctionFactory.SingleArgMathFunction,DefaultFunctionFactory.SortDatasetFunction,DefaultFunctionFactory.SplitStringFunction,DefaultFunctionFactory.StringCaseFunction,DefaultFunctionFactory.StringFormatFunction,DefaultFunctionFactory.StringTrimFunction,DefaultFunctionFactory.SubstringFunction,DefaultFunctionFactory.SwitchFunction,DefaultFunctionFactory.TimeBetweenFunction,DefaultFunctionFactory.TimePartBetweenFunction,DefaultFunctionFactory.TimestampOfFunction,DefaultFunctionFactory.ToBinaryFunction,DefaultFunctionFactory.ToHexFunction,DefaultFunctionFactory.ToMillisFunction,DefaultFunctionFactory.ToOctalFunction,DefaultFunctionFactory.TryFunction,DefaultFunctionFactory.TypeOfFunction,DefaultFunctionFactory.UrlEncode,DefaultFunctionFactory.WeeksBetweenFunction,DefaultFunctionFactory.YearsBetweenFunction,com.inductiveautomation.ignition.gateway.expressions.GatewayFunctionFactory.TranslateFunction,HasChangedFunction,JsonFormat,JsonGet,JsonSet,PerspectiveRunScriptFunction,PropertyBasedFunctionFactory.GetPropertyFunction,PropertyBasedFunctionFactory.IsDefinedFunction,PropertyFunction,ScriptFunction,TagFunction,TagFunctionFactory.DatacacheCountFunction,TagFunctionFactory.FSQLDateExtractFunction,TranslationFunction,VariableFunctions.ClearVariablesFunction,VariableFunctions.DeleteVariableFunction,VariableFunctions.GetVariableFunction,VariableFunctions.IsVariableDefinedFunction,VariableFunctions.StoreVariableFunction
public interface Function
A function is used by the FunctionExpression. It implements execute(Expression[] args) just like Expression does.
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Method Summary
Modifier and TypeMethodDescriptionvoidconnect(CommonContext context, InteractionListener updateListener) Gives the function a chance to connect itself to things, if necessary.copy()Creates a copy of this function.voidTells the function to disconnect from anything it was connected to.execute(Expression[] args) Execute this function, and return the function's qualified value.Returns a string to be used in the auto-generated function documentation.default Class<?>getType()Returns the type that this function will return upon executionvoidinitArgs(Expression[] args) Initialize this function with the given arguments.voidshutdown()Tells the function to shutdown any polling operations.voidstartup()Tells the function to startup any polling operations. 
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Method Details
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execute
Execute this function, and return the function's qualified value.- Throws:
 ExpressionException
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initArgs
Initialize this function with the given arguments. - 
getType
Returns the type that this function will return upon execution- Since:
 - 8.0, only used for intellihint completion - implementations should not rely on getType; instead coerce
 defensively using 
TypeUtilities 
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getArgDocString
String getArgDocString()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. - 
copy
Function copy()Creates a copy of this function. Each FunctionExpression will always retrieve a copy of the function that it wants. It is up to the function whether or not a true copy is retrieved, or simply a reference to the main function object. If the function stores transient data during serialization, and thus cannot be shared between expressions, a copy must be made. - 
connect
Gives the function a chance to connect itself to things, if necessary. Most functions do not have any connections. A function should notify the updateListener if they change. The implementation of InteractionListener should execute as quickly as possible, and should not block. - 
disconnect
void disconnect()Tells the function to disconnect from anything it was connected to. - 
startup
void startup()Tells the function to startup any polling operations. Functions that use this can remember the updateListener from connect() to feed update notification to. - 
shutdown
void shutdown()Tells the function to shutdown any polling operations. 
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