Filenotify

Updated 1,306 Days AgoPublic

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Eovim Plugin - Filenotify

Filenotify is an Eovim plugin that warns the user through Eovim's user interface when a file open in Eovim was changed from the outside.

Neovim API

To make filenotify work, Eovim defines two vim APIs:

• when a file has been read by neovim,
• when a file has been written by neovim.

Both APIs use the Eovim() function, with "filenotify" as the first argument:

For example, this API can be used as follows:

function! OnReadFile (file_matched)
   call Eovim("filenotify", a:file_matched, 1)
endfunction

function! OnWriteFile (file_matched)
   call Eovim("filenotify", a:file_matched, 0)
endfunction

And then triggered using neovim's autocmd:

augroup EovimFileNotify
   autocmd!
   autocmd BufNewFile,BufReadPre,FileReadPre * call OnReadFile(expand('<amatch>'))
   autocmd BufWritePre * call OnWriteFile(expand('<amatch>'))
augroup END

Design

Eovim (e.g. the filenotify plugin) is made aware when a file has been read or written thanks to the neovim API presented above. During its lifetime, filenotify follows the following statechart regarding files edited within neovim:

• Existing files read by neovim are monitored (through an Ecore_File_Monitor).
• Upon write from inside neovim, filenotify shall receive a message, to try to distinguish external writes from internal writes.
• If a file is changed and the internal write signal was not received within a given window of time, the file is marked as being changed from the outside.
• Newly created files do not need to be registered, until they are written to the disk.
• When a file is closed, it is unregistered.