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PropertyList is a mutable list of ViewModel items. Use it to manage repeating data collections from scripts (for example, menu items, inventory entries, or dynamic UI rows). A PropertyList supports:
  • Reading item count via length
  • 1-based indexed access (list[1], list[2], …)
  • Mutations (push, insert, swap, pop, shift, clear)
  • Change notifications via addListener and removeListener
For a complete working example, see the Scripting Lists demo.

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Fields

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length

The current number of items in the list. 
function handleSwap(self: MenuListController)
  if self.menu and self.menu.length >= 2 then
    self.menu:swap(1, 2)
  end
end

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addListener

Adds a listener that is called when the list changes. 
function init(self: MenuListController, context: Context): boolean
  local vmi = context:rootViewModel() :: Data.Main
  if vmi then
    self.menu = vmi.menu
    self.listChanged = listChanged

    self.menu:addListener(self.listChanged)
  else
    print('[MenuListController] Warning: Could not find Main ViewModel.')
  end

  return true
end

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removeListener

Removes a previously added list-change listener. 
function handleRemoveListener(self: MenuListController)
  if self.menu and self.listChanged then
    self.menu:removeListener(self.listChanged)
  end
end

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Methods

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push

push(vm: ViewModel) -> ()
Get the list item by index. 
function setItemLabel(menu: PropertyList, index: number, label: string)
  if index >= 1 and index <= menu.length then
    local item = menu[index] :: Data.Button
    local itemLabel = item:getString('label')
    if itemLabel then
      itemLabel.value = label
    end
  end
end
Adds a view model to the end of the list. 
function addButton(menu: PropertyList, label: string)
  local buttonVm = Data.Button.new()

    local buttonLabel = buttonVm:getString('label')
    if buttonLabel then
      buttonLabel.value = label
    end

    menu:push(buttonVm)
end

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insert

insert(vm: ViewModel, index: number) -> ()
Inserts a view model at the given index. 
function insertAt(menu: PropertyList, label: string, index: number)
  local buttonVm = Data.Button.new()

  local buttonLabel = buttonVm:getString('label')
  if buttonLabel then
    buttonLabel.value = label
  end

  local insertIndex = math.max(1, math.min(index, menu.length + 1))
  menu:insert(buttonVm, insertIndex)
end

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swap

swap(index1: number, index2: number) -> ()
Swaps the positions of the view models at index1 and index2. 
function swapItems(menu: PropertyList, index1: number, index2: number)
  local highestIndex = math.max(index1, index2)

  if menu and menu.length >= highestIndex then
    menu:swap(index1, index2)
  end
end

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pop

pop() -> ViewModel?
Removes and returns the last view model in the list. 
function handlePop(self: MenuListController)
  if self.menu then
    self.menu:pop()
  end
end

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shift

shift() -> ViewModel?
Removes and returns the first view model in the list. 
function handleShift(self: MenuListController)
  if self.menu then
    self.menu:shift()
  end
end

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clear

clear() -> ()
Removes all view models from the list. 
function handleClearItems(self: MenuListController)
  if self.menu then
    self.menu:clear()
  end
end