B4J Tutorial SithasoDaisy - Drawer Item Management - Conditional Visibility

Ola

The issue of drawer item visibility becomes interesting when you want to control which drawer items should be visible or not depending on user group permissions.
As an example we want to hide and show some of these items on condition.


We have defined our dawer & pages like this

'NB: use this to add pages that are not added to the side nav bar
Sub AddPages
    'example
    app.AddPage(pgSignIn)        'ignore
    app.AddPage(pgSignUp)        'ignore
End Sub

Our sign in / sign up page, we want them to be in the page stack but not show in the drawer.

'define the menu items fo dawe
Sub CreateDrawerMenu
    'clear the menu
    appdrawer.Clear("")
    'add a page link to the drawer
    appdrawer.AddItemPage(pgcustomer)
    appdrawer.AddItemPage(pgemails)
    appdrawer.AddItemPage(pgreminders)
    appdrawer.AddItemPage(pgcommunication)
    appdrawer.AddItemPage(pgappointment)
    appdrawer.AddItemPage(pgtasks)
    appdrawer.AddItemPage(pgdocs)
    '
    appdrawer.AddItem("paypal", "Paypal")
    appdrawer.AddItemChildPage("paypal", pgtrans)
    appdrawer.AddItemChildPage("paypal", pgsummaryperyear)
    appdrawer.AddItemChildPage("paypal", pgsummarypertranfrom)
    appdrawer.AddItemChildPage("paypal", pgsummarypername)
    appdrawer.AddItemChildPage("paypal", pgsummarypertype)
    appdrawer.AddItemChildPage("paypal", pgsummaryperstatus)
    appdrawer.AddItemChildPage("paypal", pgsummarypercountry)
    appdrawer.AddItemChildPage("paypal", pgsummarypercurrency)
    appdrawer.AddItemChildPage("paypal", pgsummaryperimpact)
    '
    appdrawer.AddItem("settings", "Settings")
    appdrawer.AddItemChildPage("settings", pgemailtemplates)
    appdrawer.AddItemChildPage("settings", pgForgotPassword)
    'appdrawer.AddItemChildPage("settings", )
End Sub

Now, depending on authentication of the user, we can control which items are visible or not, by updating the IsAuthenticated sub. Here is the update.

'show/hide drawer
Sub IsAuthenticated(b As Boolean)
    appdrawer.Close
    If b Then
        appdrawer.ShowPageLink(pgcustomer)
        appdrawer.ShowPageLink(pgemails)
        appdrawer.ShowPageLink(pgreminders)
        appdrawer.ShowPageLink(pgcommunication)
        appdrawer.ShowPageLink(pgappointment)
        appdrawer.ShowPageLink(pgtasks)
        appdrawer.ShowPageLink(pgdocs)

        appdrawer.ShowItem("paypal")
        appdrawer.ShowItem("settings")
        appdrawer.Show
        appdrawer.AdjustClippedLeft(True)
        appnavbar.Show
    Else
       
        appdrawer.HidePageLink(pgcustomer)
        appdrawer.HidePageLink(pgemails)
        appdrawer.HidePageLink(pgreminders)
        appdrawer.HidePageLink(pgcommunication)
        appdrawer.HidePageLink(pgappointment)
        appdrawer.HidePageLink(pgtasks)
        appdrawer.HidePageLink(pgdocs)
       
        appdrawer.HideItem("paypal")
        appdrawer.HideItem("settings")
        appdrawer.AdjustClippedLeft(False)
        appdrawer.Hide
        appnavbar.hide
    End If
End Sub

Because we can call these visibility controlling functions, we will add some helper functions on pgIndex

Sub ShowMenuItem(itemID As String)
    appdrawer.ShowItem(itemID)
End Sub

Sub HideMenuItem(itemID As String)
    appdrawer.HideItem(itemID)
End Sub

Sub HidePageLink(pgObj As Object)
    appdrawer.HidePageLink(pgObj)
End Sub

Sub ShowPageLink(pgObj As Object)
    appdrawer.ShowPageLink(pgObj)
End Sub

These can be called from any code module.

Happy coding...