To be able to reference same dynamic feedback Lua script in multiple mappings

[helgoboss]

Discussed in #1219

^{Originally posted by KennyG5000 September 21, 2024}
This would look like the same implementation for reusing Lua scripts across multiple MIDI script sources introduced in 2.16.0, just for dynamic feedback Lua scripts in this case thanks.

[helgoboss]

Implemented in those commits. Accidentally associated with #1219 (the discussion) instead of the issue.

[helgoboss]

Test import:

{
    kind = "MainCompartment",
    version = "2.16.9",
    value = {
        mappings = {
            {
                id = "xZgKK432NHTMRxJsGE3l3",
                name = "1",
                source = {
                    kind = "Virtual",
                    id = 0,
                },
                glue = {
                    step_size_interval = {0.01, 0.05},
                    step_factor_interval = {1, 5},
                    feedback = {
                        kind = "Dynamic",
                        script = [[
local compartment = require("compartment")
return {
    feedback_event = {
        value = compartment.text
    }
}]],
                    },
                },
                target = {
                    kind = "Dummy",
                },
            },
        },
        common_lua = "return { text = \'hello world\' }",
    },
}

Enabling virtual feedback logging will show that it uses the text provided by the common compartment Lua.

[smandrap]

Hi :) .

I’m trying to make a “function library” of compartment lua code to reuse across mappings (for blinking leds/scrolling text/etc).
It seems I’m not able to access context.prop(“xxx”) from compartment lua, but I’d like to be able to at least get global milliseconds (and possibly compartment parameters).
Is there already a way to do this? If not, would you consider an implementation?

Thanks

Edit: it seems that compartment lua code "polls" for feedback In a different way. I'll try to explain:

I tried to work around the issue by passing the parameters to the compartment functions.

Compartment Lua code:

local m = {}

function m.blinkOnOff(realearn_global_time, time_interval, ratio)
	time_interval = time_interval or 350
	ratio = ratio or 2
	local val = math.floor(realearn_global_time / time_interval) % ratio

	return val > 0
end

function m.feedback_event(val)
	return { feedback_event = { value = tostring(val)} }
end


return m

Dynamic Lua Feedback Code:

local time = context.prop("global.realearn.time")

local comp = require("compartment")
local isOn = comp.blinkOnOff(time, 350, 2)


return comp.feedback_event(isOn and "a" or "b")

Mapping (as Lua)

{
    kind = "Mapping",
    version = "2.18.0",
    value = {
        id = "WjGQ32yvO78BK82htvbMV",
        name = "101",
        tags = nil,
        group = "",
        visible_in_projection = false,
        enabled = true,
        control_enabled = true,
        feedback_enabled = true,
        activation_condition = {
            kind = "TargetValue",
            condition = "y > 0",
        },
        on_activate = {},
        on_deactivate = {},
        source = {
            kind = "Virtual",
            id = "lcd/assignment",
            character = "Multi",
        },
        glue = {
            absolute_mode = "Normal",
            source_interval = {0, 1},
            target_interval = {0, 1},
            reverse = false,
            out_of_range_behavior = "MinOrMax",
            target_value_sequence = "",
            round_target_value = false,
            wrap = false,
            jump_interval = {0, 1},
            takeover_mode = "Off",
            control_transformation = "",
            step_size_interval = {0.01, 0.05},
            step_factor_interval = {1, 1},
            relative_mode = "Normal",
            fire_mode = {
                kind = "Normal",
                press_duration_interval = {0, 0},
            },
            feedback = {
                kind = "Dynamic",
                script = [[
local time = context.prop("global.realearn.time")

local comp = require("compartment")
local isOn = comp.blinkOnOff(time, 350, 2)


return comp.feedback_event(isOn and "a" or "b")]],
            },
        },
        target = {
            kind = "Dummy",
            unit = "Native",
        },
        unprocessed = {},
    },
}

In this situation, the feedback is sent only when I control the value of the dummy (so it's actively receiving control). Consider this other mapping now:

{
    kind = "Mapping",
    version = "2.18.0",
    value = {
        id = "UW7p_B4_DkBEVlxZCkqOu",
        name = "Auto rec arm (FEEDBACK)",
        tags = nil,
        group = "arm",
        visible_in_projection = false,
        enabled = true,
        control_enabled = false,
        feedback_enabled = true,
        activation_condition = {
            kind = "TargetValue",
            mapping = "ogoM8bwG1MPCIDXiWl5vQ",
            condition = "y > 0",
        },
        on_activate = {},
        on_deactivate = {},
        source = {
            kind = "Virtual",
            id = "ch1/record-ready",
            character = "Button",
        },
        glue = {
            absolute_mode = "Normal",
            source_interval = {0, 1},
            target_interval = {0, 1},
            reverse = false,
            out_of_range_behavior = "MinOrMax",
            target_value_sequence = "",
            round_target_value = false,
            wrap = false,
            jump_interval = {0, 1},
            takeover_mode = "Off",
            control_transformation = "",
            step_size_interval = {0.01, 0.05},
            step_factor_interval = {1, 1},
            relative_mode = "Normal",
            fire_mode = {
                kind = "Normal",
                press_duration_interval = {0, 0},
            },
            feedback = {
                kind = "Dynamic",
                script = [[
local val = 0

if context.prop("target.active") then 
	val = 0
else
	local millis = context.prop("global.realearn.time") or 0
	local timeInterval = 350

	val = math.floor(millis / timeInterval) % 2
end

return {
	feedback_event = {
		value = val * 127
	}
}]],
            },
        },
        target = {
            kind = "Dummy",
            unit = "Native",
        },
        unprocessed = {},
    },
}

This works (blinks when activate) but the code is "contained" in the Dynamic feedback section. Am I missing something here?

Thanks again

[helgoboss]

Ah cool, you are using the advanced features 👍

There's only one thing you miss, and granted, it's easy to miss:

When ReaLearn queries the script in advance to know which target properties it needs, the shared code is also not available yet. Currently, you need to make sure that the target properties are queried even if require("compartment") evaluates to nil.

See docs.

So in this "preparation execution" of the script, your script fails. comp.blinkOnOff(time, 350, 2) in particular, because comp evaluates to nil.

I know, MIDI source scripts and feedback scripts are currently hard to debug. I hope to improve this at some point.