vide/docs/api/reactivity-utility.md

Reactivity API: Utility

cleanup()

Runs a callback anytime a reactive scope is re-ran.

• Type

  function cleanup(callback: () -> ())
  

• Example

  local data = source(1)
  
  effect(function()
      local label = create "TextLabel" { Text = data() }
  
      cleanup(function()
          label:Destroy()
      end)
  end)
  

  local data = source(1)
  
  derive(function()
      local label = create "TextLabel" { Text = data() }
  
      cleanup(function()
          label:Destroy()
      end)
  
      return label
  end)
  

untrack()

Runs a given function where any sources read will not track its reactive scope.

• Type

  function untrack<T>(source: () -> T): T
  

• Details

  Updates made to a source passed to untrack() will not cause updates to anything depending on that source.

• Example

  local a = source(0)
  local b = source(0)
  
  local sum = derive(function()
      return a() + untrack(b)
  end)
  
  print(sum()) -- 0
  b(1)
  print(sum()) -- 0
  a(1)
  print(sum()) -- 2