Skip to end of metadata
Go to start of metadata

This function is used by Ignition's Expression language.


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.


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.

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