[space-lua] Toggle / Rotate Header Level h1-h6-On/Off

Tricks & Techniques
4

Here is an updated version of the Header: Toggle Level commands.
This is derived from the “built-in” /h1-/h5 slash commands and added the part to handle the toggling off. More straightforward and still retains all the functions.

-- function to toggle a specific header level

local function toggleHeader(level)
  local line = editor.getCurrentLine()
  local text = line.textWithCursor

  -- Detect current header level
  local currentLevel = string.match(text, "^(#+)%s*")
  currentLevel = currentLevel and #currentLevel or 0

  local cleanText = string.gsub(text, "^#+%s*", "")

  -- Toggle: remove if same, otherwise set new level
  if currentLevel == level then
    editor.replaceRange(line.from, line.to, cleanText, true)
  else
    editor.replaceRange(line.from, line.to, string.rep("#", level) .. " " .. cleanText, true)
  end
end

-- register commands Ctrl-1 → Ctrl-6
for lvl = 1, 6 do
  command.define {
    name = "Header: Toggle Level " .. lvl,
    key = "Ctrl-" .. lvl,
    run = function() toggleHeader(lvl) end
  }
end