Added a callback that is called when the buffer is cleared. (#356)

Author: filippo-biondi

README.md

@@ -260,6 +260,8 @@ require('render-markdown').setup({
         attach = function() end,
         -- Called after plugin renders a buffer
         render = function() end,
+        -- Called after plugin clears a buffer
+        clear = function() end,
     },
     heading = {
         -- Turn on / off heading icon & background rendering

doc/limitations.md

@@ -37,9 +37,12 @@ in this plugin. Different plugins will have different setups, below are some exa
             latex = { enabled = false },
             win_options = { conceallevel = { rendered = 2 } },
             on = {
-                attach = function()
+                render = function()
                     require('nabla').enable_virt({ autogen = true })
                 end,
+                clear = function()
+                    require('nabla').disable_virt()
+                end,
             },
         },
     },

doc/render-markdown.txt

@@ -321,6 +321,9 @@ Default Configuration ~
             attach = function() end,
             -- Called after plugin renders a buffer
             render = function() end,
+            -- Called after plugin clears a buffer
+            clear = function() end,
+
         },
         heading = {
             -- Turn on / off heading icon & background rendering

lua/render-markdown/core/ui.lua

@@ -150,6 +150,7 @@ function M.run_update(buf, win, change)
         state.on.render({ buf = buf })
     else
         M.clear(buf, buffer_state)
+        state.on.clear({ buf = buf })
     end
 end
 

lua/render-markdown/init.lua

@@ -21,6 +21,7 @@ local M = {}
 ---@class (exact) render.md.UserCallback
 ---@field public attach? fun(ctx: render.md.CallbackContext)
 ---@field public render? fun(ctx: render.md.CallbackContext)
+---@field public clear? fun(ctx: render.md.CallbackContext)
 
 ---@class (exact) render.md.UserInjection
 ---@field public enabled? boolean
@@ -401,6 +402,8 @@ M.default_config = {
         attach = function() end,
         -- Called after plugin renders a buffer
         render = function() end,
+        -- Called after plugin clears a buffer
+        clear = function() end,
     },
     heading = {
         -- Turn on / off heading icon & background rendering

lua/render-markdown/state.lua

@@ -335,7 +335,7 @@ function M.validate()
                 :check()
         end)
         :nested('on', function(on)
-            on:type({ 'attach', 'render' }, 'function'):check()
+            on:type({ 'attach', 'render' , 'clear'}, 'function'):check()
         end)
         :nested('overrides', function(overrides)
             overrides

lua/render-markdown/types.lua

@@ -3,6 +3,7 @@
 ---@class (exact) render.md.Callback
 ---@field public attach fun(ctx: render.md.CallbackContext)
 ---@field public render fun(ctx: render.md.CallbackContext)
+---@field public clear fun(ctx: render.md.CallbackContext)
 
 ---@class (exact) render.md.Injection
 ---@field public enabled boolean