feat: closes #85, add file_open_requested event to override built-in logic

Author: cseickel

doc/neo-tree.txt

@@ -431,9 +431,18 @@ Fired after a file (or folder) has been deleted. The arg is the full path to the
 deleted file.
 
 "file_moved"
-Fired after a file (or folder) has been moved. The arg is an table containing
+Fired after a file (or folder) has been moved. The arg is a table containing
 `source` and `destination` properties.
 
+"file_open_requested"
+Fired just before a file is opened. The arg is a table containing the `state`
+of the source being used, the `path` of the file to be opened, and `open_cmd`,
+which is the open command that was requested. `open_cmd` will be either |edit|,
+|split|, or |vsplit|. This function should return a table with a property called
+`handled` which is true if the file open operation was handled, or false if it
+was not. If `{ handled = true }` is not returned, the file will be opened using
+the built-in logic.
+
 "file_opened"
 Fired after a file has been opened. You might use this to auto-close the window
 or clear the filter. The arg is the path of the file opened.

lua/neo-tree/events/init.lua

@@ -9,6 +9,7 @@ local M = {
   FILE_ADDED = "file_added",
   FILE_DELETED = "file_deleted",
   FILE_MOVED = "file_moved",
+  FILE_OPEN_REQUESTED = "file_open_requested",
   FILE_OPENED = "file_opened",
   FILE_RENAMED = "file_renamed",
   FS_EVENT = "fs_event",

lua/neo-tree/events/queue.lua

@@ -128,6 +128,18 @@ local fire_event_internal = function(event, args)
       local id = event_handler.id or event_handler
       if success then
         log.trace("Handler ", id, " for " .. event .. " called successfully.")
+        if
+          type(result) == "table"
+          and type(result.handled) == "boolean"
+          and result.handled == true
+        then
+          log.trace(
+            "Handler ",
+            id,
+            " for " .. event .. " returned handled = true, skipping the rest of the queue."
+          )
+          return result
+        end
       else
         log.error(string.format("Error in event handler for event %s[%s]: %s", event, id, result))
       end
@@ -145,7 +157,7 @@ M.fire_event = function(event, args)
       fire_event_internal(event, args or {})
     end, freq)
   else
-    fire_event_internal(event, args or {})
+    return fire_event_internal(event, args or {})
   end
 end
 

lua/neo-tree/utils.lua

@@ -302,6 +302,16 @@ end
 M.open_file = function(state, path, open_cmd)
   open_cmd = open_cmd or "edit"
   if M.truthy(path) then
+    local events = require("neo-tree.events")
+    local event_result = events.fire_event(events.FILE_OPEN_REQUESTED, {
+      state = state,
+      path = path,
+      open_cmd = open_cmd,
+    }) or {}
+    if event_result.handled then
+      events.fire_event(events.FILE_OPENED, path)
+      return
+    end
     -- use last window if possible
     local suitable_window_found = false
     local nt = require("neo-tree")
@@ -337,7 +347,6 @@ M.open_file = function(state, path, open_cmd)
     else
       vim.cmd(open_cmd .. " " .. path)
     end
-    local events = require("neo-tree.events")
     events.fire_event(events.FILE_OPENED, path)
   end
 end