Added "post_execute" callback

pyluatex.lua

@@ -42,6 +42,10 @@ local parent_env = nil
 local last_code = nil
 local last_output = nil
 
+local callback_handlers = {
+    post_execute = {}
+}
+
 local function get_tex_file_folder()
     for _, v in ipairs(arg) do
         if v:sub(1, 1) ~= "-" then
@@ -145,6 +149,17 @@ function pyluatex.execute(code, auto_print, write, repl_mode, store)
         last_output = output_lines
     end
 
+    for _, handler in pairs(callback_handlers["post_execute"]) do
+        handler({
+            session = pyluatex.session,
+            success = resp.success,
+            code = code_lines,
+            output = output_lines,
+            log_message = resp.log_msg,
+            repl_mode = repl_mode
+        })
+    end
+
     if pyluatex.verbose or not resp.success then
         texio.write_nl('PyLuaTeX input for session "' .. pyluatex.session ..
             '": ' .. full_code)
@@ -222,6 +237,38 @@ function pyluatex.get_last_output()
     return last_output
 end
 
+function pyluatex.register_event_handler(event, name, handler)
+    local handlers = callback_handlers[event]
+    if handlers ~= nil then
+        if handlers[name] ~= nil then
+            show_err(
+                'Event handler "' .. name .. '" already registered' ..
+                ' for event "' .. event .. '"'
+            )
+            return
+        end
+        handlers[name] = handler
+    else
+        show_err('Unknown event "' .. event .. '"')
+    end
+end
+
+function pyluatex.unregister_event_handler(event, name)
+    local handlers = callback_handlers[event]
+    if handlers ~= nil then
+        if handlers[name] == nil then
+            show_err(
+                'Event handler "' .. name .. '" not registered' ..
+                ' for event "' .. event .. '"'
+            )
+            return
+        end
+        handlers[name] = nil
+    else
+        show_err('Unknown event "' .. event .. '"')
+    end
+end
+
 local function parse_bool(name, value)
     value = value:fullstrip()
     if value == "true" then

test/test-cases/callback.yaml

@@ -0,0 +1,79 @@
+tests:
+- code: |
+    \directlua{
+      pyluatex.register_event_handler(
+        "post_execute",
+        "handler_name",
+        function() texio.write("CALLBACK TEST") end
+      )
+    }
+    \py{1}
+  log: CALLBACK TEST
+  pdf: 1
+- success: false
+  code: |
+    \directlua{
+      pyluatex.register_event_handler(
+        "unknown_event",
+        "handler_name",
+        function() texio.write("CALLBACK TEST") end
+      )
+    }
+  log: |
+    ! Package PyLuaTeX Error: Unknown event "unknown_event".
+- success: false
+  code: |
+    \directlua{
+      pyluatex.register_event_handler(
+        "post_execute",
+        "handler_name",
+        function() texio.write("CALLBACK TEST") end
+      )
+      pyluatex.register_event_handler(
+        "post_execute",
+        "handler_name",
+        function() texio.write("CALLBACK TEST") end
+      )
+    }
+  log: |
+    ! Package PyLuaTeX Error: Event handler "handler_name" already registered for e
+    vent "post_execute".
+- code: |
+    \directlua{
+      pyluatex.register_event_handler(
+        "post_execute",
+        "handler_name",
+        function() texio.write("CALLBACK TEST") end
+      )
+      pyluatex.unregister_event_handler("post_execute", "handler_name")
+    }
+  not_log: CALLBACK TEST
+- success: false
+  code: |
+    \directlua{
+      pyluatex.unregister_event_handler("post_execute", "handler_name")
+    }
+  log: |
+    ! Package PyLuaTeX Error: Event handler "handler_name" not registered for event
+     "post_execute".
+- success: false
+  code: |
+    \directlua{
+      pyluatex.unregister_event_handler("unknown_event", "handler_name")
+    }
+  log: |
+    ! Package PyLuaTeX Error: Unknown event "unknown_event".
+- code: |
+    \directlua{
+      function handler(info)
+        texio.write_nl("TEST")
+        texio.write_nl("Code: " .. table.concat(info.code))
+      end
+
+      pyluatex.register_event_handler("post_execute", "handler_name", handler)
+    }
+    \py{1}
+  log: |
+    TEST
+    Code: 1
+  pdf: 1