Back to FabImage Library website

You are here: Start » Function Reference » All Functions » Loop Utils » TestObjectChanged

TestObjectChanged


This is Filter Equivalent. This function may be present in generated code, but should not be used in hand-written code.

Header: STD.h
Namespace: fil
Module: FoundationLite

Checks if the input object is different than in the previous iteration.

Syntax

void fil::TestObjectChanged
(
	const Type& inObject,
	bool inInitialResult,
	bool inReset,
	bool& outObjectChanged,
	Type& outPreviousObject
)

Parameters

Name Type Default Description
Input value
 inObject const Type&
Input value
 inInitialResult bool Result of the filter at first iteration
Input value
 inReset bool False Reset accumulator state
Output value
 outObjectChanged bool& Is object changed
Output value
 outPreviousObject Type& Object from previous iteration (in first iteration equals inObject)

Description

This filter checks if an object has changed between consecutive iterations. It is especially useful in working with I/O and allows to execute a part of an application only when some I/O data has changed. This filter can be also used as an input of macrofilter variant.

Input inInitialResult allows for setting the initial output of the filter. This is useful to force some computations at the start of application.

In first iteration output outPreviousObject is equal to value on inObject

Remarks

When working with HMI, a more recommended way of detecting changes is to use appropriate properties of HMI Controls such as TrackBar.outValueChanged.

This filter can be replaced with the following formula:

See Also

  • CopyObject – Creates a copy of the input data.