allow non-persistent layout

README.md

@@ -33,16 +33,13 @@ The package comes with the icon for `layoutbox`, which can be set with the follo
 
 Use `layout = machi.layout.create(name, editor)` to instantiate the layout with an editor object.
 
-`name` can be a string or a function taking a tag object and returning a string.
+`name` can be a string or a function returning a string (see `init.lua` and "Advanced" below).
 This is used for having different actual layout dependent on tags.
 
 `editor` are used for editing and persisting the layouts.
 `machi.default_editor` can be used, or see below on creating editors.
 You can create multiple layouts with different names and share the same editor.
 
-The default layout, `machi.default_layout`, uses the screen geometry and the tag name for name, thus allows the actual layout to be tag- and screen-dependent.
-To differentiate tags with the same name, you may need a more advanced naming function.
-
 ## Editor
 
 Call `editor = machi.editor.create()` to create an editor.
@@ -130,6 +127,16 @@ So far, the key binding is not configurable. One has to modify the source code t
 `machi.editor.fit_region(c, cycle = false)` will fit a floating client into the closest region.
 If `cycle` is true, it then moves the window by cycling all regions.
 
+## Advanced
+
+# `name` as a function in `machi.layout.create`
+
+When passed in as a function, `name` takes the tag `t` and a boolean flag `p` and returns a function for the tag-dependent name of the layout.
+Flag `p` is set true when the name is used for persisting the layout. If the layout is not intented to persist, returning `nil` when `p` is true to skip persisting.
+
+The default layout, `machi.default_layout`, uses the screen geometry and the tag name for name, thus allows the actual layout to be tag- and screen-dependent.
+To differentiate tags with the same name, you may need a more advanced naming function.
+
 ## Caveats
 
 `beautiful.useless_gap` is handled differently in layout-machi and it doesn't cooperate well with the standard way.

editor.lua

@@ -652,25 +652,26 @@ local function create(data)
                         end
                         -- bring the current cmd to the front
                         data.cmds[#data.cmds + 1] = current_cmd
-                        if not layout.is_dynamic then
-                           data.last_cmd[layout.machi_get_instance_name(tag)] = current_cmd
-                        end
 
-                        if data.history_file then
-                           local file, err = io.open(data.history_file, "w")
-                           if err then
-                              print("cannot save history to " .. data.history_file)
-                           else
-                              for i = max(1, #data.cmds - data.history_save_max + 1), #data.cmds do
-                                 print("save cmd " .. data.cmds[i])
-                                 file:write(data.cmds[i] .. "\n")
-                              end
-                              for name, cmd in pairs(data.last_cmd) do
-                                 print("save last cmd " .. cmd .. " for " .. name)
-                                 file:write("+" .. name .. "\n" .. cmd .. "\n")
+                        local instance_name = layout.machi_get_instance_name(tag, true)
+                        if instance_name ~= nil then
+                           data.last_cmd[instance_name] = current_cmd
+                           if data.history_file then
+                              local file, err = io.open(data.history_file, "w")
+                              if err then
+                                 print("cannot save history to " .. data.history_file)
+                              else
+                                 for i = max(1, #data.cmds - data.history_save_max + 1), #data.cmds do
+                                    print("save cmd " .. data.cmds[i])
+                                    file:write(data.cmds[i] .. "\n")
+                                 end
+                                 for name, cmd in pairs(data.last_cmd) do
+                                    print("save last cmd " .. cmd .. " for " .. name)
+                                    file:write("+" .. name .. "\n" .. cmd .. "\n")
+                                 end
                               end
+                              file:close()
                            end
-                           file:close()
                         end
 
                         current_info = "Saved!"

init.lua

@@ -3,7 +3,7 @@ local editor = require(... .. ".editor")
 local switcher = require(... .. ".switcher")
 local default_editor = editor.create()
 local default_layout = layout.create(
-   function (tag)
+   function (tag, _persist)
       if tag.machi_name_cache == nil then
          tag.machi_name_cache =
             tostring(tag.screen.geometry.width) .. "x" .. tostring(tag.screen.geometry.height) .. "+" ..

layout.lua

@@ -51,11 +51,11 @@ local function create(name, editor)
    if type(name) == "function" then
       get_instance_name = name
    else
-      get_instance_name = function (tag) return name end
+      get_instance_name = function () return name end
    end
 
    local function get_instance(tag)
-      local name = get_instance_name(tag)
+      local name = get_instance_name(tag, false)
       if instances[name] == nil then
          instances[name] = {
             cmd = editor.get_last_cmd(name),