Where did my assert go?

[raymanningphotography]

I'm having problems with error dialogs inside of event handlers (excuse me if that's not the vernacular used for LUA/LR). The code below opens a dialog with a single button which causes an assert(false) condition. Inside the handler, there is no error message box displayed. Outside the handler, an error message is displayed. I've tried calling LrDialogs.attachErrorDialogToFunctionContext with no change and I also tried wrapping showCustomDialog and the anonymous action with John R. Ellis's showErrors and still do not get an error message.

What am I missing?

-- required imports

local LrDialogs = import "LrDialogs"

local LrTasks = import "LrTasks"

local LrView = import "LrView"

local LrFunctionContext = import "LrFunctionContext"

local function showCustomDialog()

  LrFunctionContext.callWithContext(

  "showCustomDialog",

  function( context )

  -- This assert will show a dialog

  -- assert(false,"false assertion")

  local viewFactory = LrView.osFactory()

  local content = viewFactory:push_button

  {

  title = "Push Me",

  action = function()

  -- this does not show a dialog

  assert(false,"false assertion")

  end

  }

  LrDialogs.presentFloatingDialog(

  _PLUGIN,

  {

  title = "My Dialog",

  contents = content,

  }

  )

  end)

end

LrTasks.startAsyncTask(showCustomDialog)

[johnrellis · Accepted solution]

When I wrap the functions passed to the SDK with Debug.showErrors(), the assertion error is trapped by Debug:

local Require = require 'Require'.path ("../common").reload ()
local Debug = require 'Debug'.init ()
require 'strict'
local LrDialogs = import "LrDialogs"
local LrFunctionContext = import "LrFunctionContext"
local LrTasks = import "LrTasks"
local LrView = import "LrView"
local showErrors = Debug.showErrors
local function showCustomDialog()
    LrFunctionContext.callWithContext ("showCustomDialog", 
    showErrors (function( context )
        local viewFactory = LrView.osFactory()
        local content = viewFactory:push_button {title = "Push Me",
            action = showErrors (function()
                assert (false, "false assertion")
                end)}
        LrDialogs.presentFloatingDialog (_PLUGIN, {title = "My Dialog",
            contents = content})
        end))
    end
LrTasks.startAsyncTask (showErrors (showCustomDialog))

I'm using the most recent version of the debugging toolkit, but I'm sure that the old version would also trap the error.

[raymanningphotography]

Thanks John!  I'm not exactly sure what was happening. I'm not able to reproduce what I saw (or I think I saw). I also started hitting an error that closeWindow was being called on a nil window. A restart of lightroom seems to have corrected that.

[johnrellis]

I've found restarting LR and going to bed often solves mysterious LR problems...