hasChanged

This function is used by Ignition's Expression language.

Description

note

This function is only available in Transaction Group Expression Items and Expression Tags.

This function returns True if the given value has changed since the last time the Expression Item was run. Setting the optional boolean argument "include quality" to true means a quality change will make this function return true.

Syntax

hasChanged(value[, includeQuality])

• Parameters

  • object value - The number value to check for change

  • bool includeQuality - Optional. A flag that indicates if a quality change will also trigger this tag.

• Results

  • bool - True if the value has changed since the last time the expression was evaluated, False if not.

Examples

Code Snippet

hasChanged({reference to another Expression Item}) //would return true if the referenced value has changed since the last group execution