Plugin code help for writing metadata

Here's your previous script modified so the Rate 1 button works. Changes:

1. Integrated with the debugging toolkit.  Debug.showErrors() wraps every function passed back into the SDK API. That allows errors to be displayed rather than silently discarded.

2. The action for the "Rate 1" button calls setRating() in an async task.

3. In setRating(), LrTasks.pcall() is used instead of the Lua built-in pcall().  The built-in pcall() interferes with LR's tasking and the called function is always invoked in the main task. The documentation for this is buried in the API reference for LrTasks.

4. The action for "Rate 1" was calling LrDialogs.stopModalWithResult (contents, ...).  But "contents" wasn't yet defined:

local contents = ... stopModalWithResult (contents, ...) ...

(The local variable "contents" isn't defined until after the "local" statement.)

Here's the modified script:

local Require = require 'Require'.path ("../common")
local Debug = require 'Debug'.init ()
require 'strict'

local LrApplication = import 'LrApplication'
local LrDialogs = import 'LrDialogs'
local LrFunctionContext = import 'LrFunctionContext'
local LrTasks = import 'LrTasks'
local LrView = import 'LrView'
local LrLogger = import 'LrLogger'

local showErrors = Debug.showErrors


-- Initialize logger with default Lightroom log location
local logger = LrLogger('ImageRaterLogger')
logger:enable("logfile")
logger:info("Logger initialized.")
LrDialogs.message("Logger initialized.") -- Debug message

-- Function to set a rating
local function setRating(rating)
    LrDialogs.message("setRating function called with rating: " .. (rating or "nil")) -- Debug message
    local catalog = LrApplication.activeCatalog()
    local photo = catalog:getTargetPhoto()

    if photo then
        LrDialogs.message("Photo selected. Attempting to set rating: " .. (rating or "nil")) -- Debug message
        LrFunctionContext.callWithContext("Set Rating Context 1", showErrors (function(context)
            end))

        LrFunctionContext.callWithContext("Set Rating Context", showErrors (function(context)
            local success, err = LrTasks.pcall(showErrors (function()
                catalog:withWriteAccessDo("Set Rating", function()
                    photo:setRawMetadata('rating', rating)
                end, {
                    timeout = 1, -- Wait for up to 1 second for write access
                    callback = function()
                        LrDialogs.message("Write access timeout. Could not set rating.") -- Debug message
                    end
                })
            end))


            if success then
                LrDialogs.message("Rating set successfully.") -- Debug message
            else
                LrDialogs.message("Failed to set rating: " .. (err or "Unknown error")) -- Debug message
            end

            local message = rating and ("Rated " .. rating .. " stars") or "Rating cleared"
            LrDialogs.showBezel(message)
        end))
    else
        LrDialogs.message("No photo selected. Cannot set rating.") -- Debug message
    end
end

-- Show the rating dialog
local function showRater()
    local catalog = LrApplication.activeCatalog()
    if not catalog then
        logger:info("No active catalog found.")
        LrDialogs.message("No active catalog found.") -- Debug message
        return
    end

    local photo = catalog:getTargetPhoto()
    if not photo then
        logger:info("No photo selected in catalog.")
        LrDialogs.message("No photo selected in catalog.") -- Debug message
        LrDialogs.message("Please select a photo", "No photo selected", "info")
        return
    end

    logger:info("Photo selected. Showing rating dialog.")
    LrDialogs.message("Photo selected. Showing rating dialog.") -- Debug message

    local f = LrView.osFactory()

    local contents
    contents = f:column {
        spacing = f:control_spacing(),

        f:row {
            f:push_button {
                title = "Rate 1",
                action = showErrors (function()
                    LrTasks.startAsyncTask (showErrors (function ()
                        LrDialogs.message("Rate 1 button clicked") -- Debug message
                        setRating(1)
                        LrDialogs.stopModalWithResult(contents, "ok")
                        end))
                end),
            },
            f:push_button {
                title = "Rate 2",
                action = function()
                    LrDialogs.message("Rate 2 button clicked") -- Debug message
                    setRating(2)
                    LrDialogs.stopModalWithResult(contents, "ok")
                end,
            },
            f:push_button {
                title = "Rate 3",
                action = function()
                    LrDialogs.message("Rate 3 button clicked") -- Debug message
                    setRating(3)
                    LrDialogs.stopModalWithResult(contents, "ok")
                end,
            },
        },

        f:row {
            f:push_button {
                title = "Rate 4",
                action = function()
                    LrDialogs.message("Rate 4 button clicked") -- Debug message
                    setRating(4)
                    LrDialogs.stopModalWithResult(contents, "ok")
                end,
            },
            f:push_button {
                title = "Rate 5",
                action = function()
                    LrDialogs.message("Rate 5 button clicked") -- Debug message
                    setRating(5)
                    LrDialogs.stopModalWithResult(contents, "ok")
                end,
            },
            f:push_button {
                title = "Clear Rating",
                action = function()
                    LrDialogs.message("Clear Rating button clicked") -- Debug message
                    setRating(nil)
                    LrDialogs.stopModalWithResult(contents, "ok")
                end,
            },
        },
    }

    LrDialogs.presentModalDialog({
        title = "Rate Image",
        contents = contents,
    })
end

-- Start the task
LrTasks.startAsyncTask(showErrors (showRater))