Update for Ribbon menu with ExcelDna and F#

Ribbon F#

// typos fixed in:
// http://bramjochems.com/blog/2014/05/creating-ribbon-menu-exceldna-f/


module RibbonBuilder =
    // http://bramjochems.com/blog/2014/05/creating-ribbon-menu-exceldna-f/

    type RibbonButtonSize =
        | Large
        | Medium
        | Small
 
    type RibbonButtonCallbackType =
        | AddinCallBack
        | RunMacro of macroname : string
 
    type RibbonButton =
        { id : string;
          label : string;
          size  : RibbonButtonSize;
          image : string Option;
          callback : RibbonButtonCallbackType;
          screentip : string option;
          supertip : string option }
 
    type RibbonGroup =
        { id : string;
          label : string;
          buttons : RibbonButton list }
 
    //module RibbonBuilder =
 
    [<Literal>]
    let startString = @"<customUI xmlns='http://schemas.microsoft.com/office/2009/07/customui' loadImage='LoadImage'><ribbon><tabs>"
     
    [<Literal>]
    let endString = @"</tabs></ribbon></customUI>"
    
    // Helper function to create a reoccuring string pattern
    let private createHelperString field value =
        match value with
            | None    -> " "
            | Some(v) -> field + "='" + v + "' "
 
    // Creates the xml required for a single button on the ribbon
    let private createButtonXml (button : RibbonButton) =
        let buttonOpeningString = @"<button "
        let buttonCloseString = @"/>"
        let idString = createHelperString "id" (Some(button.id))
        let labelString = createHelperString "label" (Some(button.label))
        let sizeString = match button.size with
                                | Large -> "large"
                                | Medium-> "medium"
                                | Small -> "small"
                            |> Some
                            |> createHelperString "size"
        let imageString = createHelperString "image" button.image
        let callBackString = match button.callback with
                                    | AddinCallBack -> createHelperString "onAction" (Some("OnButtonPressed"))
                                    | RunMacro(tag) -> createHelperString "onAction" (Some("RunTagMacro")) +
                                                        createHelperString "tag" (Some(tag))
        let screentipString = createHelperString "screentip" button.screentip
        let supertipString = createHelperString "supertip" button.supertip
        buttonOpeningString + idString + labelString + sizeString + imageString + callBackString + screentipString + supertipString + buttonCloseString
                        
    // Creates the xml for a group on the ribbon               
    let private createGroupXml (group : RibbonGroup)=
        let groupStartString = @"<group id='" + group.id + @"' label='" + group.label + @"'>"
        let groupEndString = @"</group>"
        let buttonString = group.buttons |> List.fold (fun acc el -> acc + createButtonXml el) ""
        groupStartString + buttonString + groupEndString
 
    // creates an xml string that defines a ribbon with a single tab
    let buildRibbon (tabId, tabLabel) (ribbonGroups : RibbonGroup list)=
        let tabStartString = @"<tab id='" + tabId + @"' label='" + tabLabel + @"'>"
        let tabEndString = @"</tab>"
        let groupString = ribbonGroups |> List.fold (fun acc el -> acc + createGroupXml el) ""
        startString + tabStartString + groupString + tabEndString + groupString

//================================
// Usage :
//================================

module buttonsIds =
    [<Literal>]
    let First = "A"
    [<Literal>]
    let Second = "B"
 
open ExcelDna.Integration.CustomUI
open RibbonBuilder

//[<ComVisible(true)>] // not needed ??
type MyRibbonC() =
    inherit ExcelRibbon()
    member x.OnButtonPressed(control:IRibbonControl) =
        match control.Id with
            | buttonsIds.First ->  System.Windows.Forms.MessageBox.Show "Hello from A!" |> ignore // Insert desired logic her
            | buttonsIds.Second->  System.Windows.Forms.MessageBox.Show "Hello from B!" |> ignore // Insert desired logic here
            |_ ->  System.Windows.Forms.MessageBox.Show "Hello from FFail!" |> ignore // or fail...
 
    override x.GetCustomUI(uiname) =
        let buttonA = { 
            id="A"; 
            label="A Lable"; 
            size = Large; 
            image = None; 
            callback = AddinCallBack; 
            screentip = Some("Button A action"); 
            supertip = None }

        let buttonB = { 
            id="B"; 
            label="Button B"; 
            size = Medium; 
            image = None; 
            callback = AddinCallBack; 
            screentip = Some("Button B action"); 
            supertip = None }  
                      
        RibbonBuilder.buildRibbon ("myTab", "ExcelDna Ribbon Tab") [{ id = "group1"; label = "Group name"; buttons = [buttonA; buttonB] }]