> ## Content Index > Fetch the complete content index at: https://nolongerset.com/llms.txt > Use this file to discover other available public pages before exploring further. # Returning Values By Reference in Ribbon Callbacks - URL: https://nolongerset.com/byref-ribbon-callbacks/ - Published: 2023-03-18T02:05:58.000Z - Updated: 2026-05-08T12:51:01.000Z - Description: To return a value from a ribbon callback, you need to pass the value back to the calling procedure using an argument that has been passed by reference. - Author: Mike Wolfe - Tags: Subs vs. Functions, Ribbon, #Import 2026-05-20 02:59 This article is one in a [series on Subs vs. Functions](https://nolongerset.com/subs-vs-functions/) in VBA. --- One of the "additional facts" from my Subs vs. Functions article was this: > Sometimes you MUST use a `Sub`, *even if you *do need* its return value* (e.g., ribbon callbacks). This is something of a corollary to the fact that [sometimes you MUST use a Function, even if you **don't need** its return value](https://nolongerset.com/functions-called-from-property-sheet/). ## Ribbon Callbacks An Office [ribbon callback](https://nolongerset.com/ribbon-callbacks/) is a VBA subroutine that gets triggered in response to various ribbon events. Some events occur automatically, such as when the ribbon initially loads. Other events occur in response to user actions, such as clicking on a button. Some callbacks can be forced to run by using the [Invalidate method](https://learn.microsoft.com/en-us/office/vba/api/Office.IRibbonUI.Invalidate), which forces reevaluation of every callback in the ribbon, or the [InvalidateControl method](https://learn.microsoft.com/en-us/office/vba/api/office.iribbonui.invalidatecontrol), which is restricted to a single control. Some [ribbon callbacks](https://learn.microsoft.com/en-us/previous-versions/office/developer/office-2007/aa722523%28v=office.12%29#how-can-i-determine-the-correct-signatures-for-each-callback-procedure), such as those associated with the **getVisible** and **getEnabled** ribbon properties, must return information to the Ribbon UI. Others, such as those set in the **onAction** and **onChange** properties, are simply raised by the ribbon but do not return information to the ribbon. ## "Returning" Values to a Ribbon Callback For technical reasons having to do with [COM](https://nolongerset.com/what-the-heck-is-com/), you cannot use a Function to return a value to the ribbon. To return a value from a ribbon callback, you need to pass the value back to the calling procedure using an argument that has been [passed by reference](https://nolongerset.com/one-if-by-val-two-if-by-ref/). When you pass an argument by reference, you pass a reference to the memory location of the variable, rather than a copy of the variable itself. This means that any changes made to the variable within the called Sub are reflected in the calling procedure. For example, consider a ribbon button defined with the following XML: ```xml