;;; etherpad.el --- Interface to the Etherpad API -*- coding: utf-8; lexical-binding: t -*- ;; Copyright 2020 FoAM ;; ;; Author: nik gaffney ;; Created: 2020-08-08 ;; Version: 0.1 ;; Package-Requires: ((emacs "26.3") (request "0.3") (let-alist "0.0") (websocket "1.12") (parsec "0.1") (0xc "0.1")) ;; Keywords: comm, etherpad, collaborative editing ;; URL: https://github.com/zzkt/ethermacs ;; This file is not part of GNU Emacs. ;; This program is free software; you can redistribute it and/or modify ;; it under the terms of the GNU General Public License as published by ;; the Free Software Foundation, either version 3 of the License, or ;; (at your option) any later version. ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; You should have received a copy of the GNU General Public License ;; along with this program. If not, see . ;;; Commentary: ;; Etherpad is a highly customizable Open Source online editor providing ;; collaborative editing in really real-time. ;; ;; This package enables read-write access to pads on an Etherpad server ;; as if they were filelike but is not (yet) suitable for use as a ;; collaborative Etherpad client. ;; ;; details -> https://etherpad.org/doc/v1.8.5/#index_http_api ;; known bugs, limitations, shortcomings, etc ;; - various problems with realtime editing using easysync ;; - the server and api key could be buffer local to enable editing on more than one server ;; - doesn't automate API interface generation from openapi.json ;; - not much in the way of error checking or recovery ;; - etc ;;; Code: (add-to-list 'load-path ".") (require 'let-alist) (require 'ethersync) (require 'request) (require 'cl-lib) (defgroup etherpad nil "Etherpad edits." :prefix "etherpad-" :group 'external) (defcustom etherpad-apikey "request an API key" "API key for the etherpad server." :type 'string) (defcustom etherpad-server "https://example.org" "URL of the etherpad server." :type 'string) (defcustom etherpad-autosync nil "Sync with etherpad server whenever the local buffer changes." :type 'boolean) (defcustom etherpad-idlesync nil "Sync with etherpad server whenever auto-save is triggered." :type 'boolean) (defvar etherpad--local-pad-name "" "Buffer local pad details.") (defvar etherpad--local-pad-revision "" "Buffer local pad details.") (define-minor-mode etherpad-mode "Minor mode to sync changes with etherpad." :lighter " etherpad" :keymap (make-sparse-keymap) (if etherpad-mode (ethersync--add-change-hooks) (ethersync--remove-change-hooks))) ;; API functions (defun etherpad-openapi () "Find API details using openAPI endpoint. Should be available at https:///api/1/openapi.json" (interactive) (request (format "%s/api/1/openapi.json" etherpad-server) :sync t :parser 'json-read :success (cl-function (lambda (&key data &allow-other-keys) (message "200: %s" data))) :error (cl-function (lambda (&rest args &key error-thrown &allow-other-keys) (message "etherpad API error: %s" error-thrown))))) (defun etherpad--api-pad-revision (pad-id) "Current revision number for the pad with PAD-ID." (catch 'rev (request (format "%s/api/1/getRevisionsCount?padID=%s&apikey=%s" etherpad-server pad-id etherpad-apikey) :sync t :parser 'json-read :success (cl-function (lambda (&key data &allow-other-keys) (let-alist data (throw 'rev .data.revisions)))) :error (cl-function (lambda (&rest args &key error-thrown &allow-other-keys) (error "Etherpad API error: %s" error-thrown)))))) (defun etherpad--api-get-text (pad-id) "Get the text of a pad with PAD-ID." (catch 'text (request (format "%s/api/1/getText?padID=%s&apikey=%s" etherpad-server pad-id etherpad-apikey) :sync t :parser 'json-read :success (cl-function (lambda (&key data &allow-other-keys) (let-alist data (throw 'text .data.text)))) :error (cl-function (lambda (&rest args &key error-thrown &allow-other-keys) (error "Etherpad API error: %s" error-thrown)))))) (defun etherpad--api-set-text (pad-id text) "Overwrite the contents of the pad PAD-ID with some TEXT." (request (format "%s/api/1/setText" etherpad-server) :type: "POST" :data `(("apikey" . ,etherpad-apikey) ("padID" . ,pad-id) ("text" . ,text)) :parser 'json-read :success (cl-function (lambda (&key data &allow-other-keys) (message "written to %s: %s\ndata: %s\n" pad-id text data))) :error (cl-function (lambda (&rest args &key error-thrown &allow-other-keys) (error "Etherpad API error: %s" error-thrown))))) ;;;###autoload (defun etherpad-edit (&optional pad-id) "Edit a pad with the given PAD-ID." (interactive "sName of the pad to edit: ") ;; note: check if pad-id exists and/or create new pad as required (let* ((pad-remote-revision (etherpad--api-pad-revision pad-id)) (pad-buffer (get-buffer-create (format "%s:%s at %s" pad-id pad-remote-revision etherpad-server))) (pad-text (etherpad--api-get-text pad-id))) (with-current-buffer pad-buffer (setq-local etherpad--local-pad-name pad-id etherpad--local-pad-revision (etherpad--api-pad-revision pad-id)) (goto-char (point-min)) (erase-buffer) (insert pad-text) (message "opening pad: %s rev: %s" etherpad--local-pad-name etherpad--local-pad-revision) (goto-char (point-max)) (display-buffer pad-buffer) (make-local-variable 'etherpad-autosync) (when etherpad-autosync (etherpad-autosync-enable)) (when etherpad-idlesync (etherpad-idlesync-enable))) (set-buffer pad-buffer))) (defun etherpad-update (&optional pad-id) "Update current buffer with text from a remote pad (PAD-ID)." (interactive "sName of the pad to sync from: ") (when (not pad-id) (setq pad-id etherpad--local-pad-name)) (message "pad-id: %s etherpad--local-pad-name: %s (buffer local)" pad-id etherpad--local-pad-name) ;; note: check if pad-id exists and/or create new pad as required (let* ((pad-remote-revision (etherpad--api-pad-revision pad-id)) (pad-buffer (current-buffer)) (pad-text (etherpad--api-get-text pad-id))) (with-current-buffer pad-buffer (setq-local etherpad--local-pad-name pad-id etherpad--local-pad-revision pad-remote-revision) (rename-buffer (format "%s:%s at %s" etherpad--local-pad-name etherpad--local-pad-revision etherpad-server)) (goto-char (point-min)) (erase-buffer) (insert pad-text) (message "synced from pad: %s rev: %s" etherpad--local-pad-name etherpad--local-pad-revision) (goto-char (point-max)) (display-buffer pad-buffer) pad-buffer))) ;;;###autoload (defun etherpad-save () "Write a buffer to an etherpad. 'etherpad--local-pad-name' and 'etherpad--local-pad-revision' are buffer local" (interactive) ;; show diffs, merge, update, etc+ ;; and save... (message "preparing to write %s revision %s (from '%s')" etherpad--local-pad-name (1+ etherpad--local-pad-revision) (current-buffer)) ;; check for version drift & update revision (let* ((remote-revision (etherpad--api-pad-revision etherpad--local-pad-name)) (local-revision etherpad--local-pad-revision)) (if (> remote-revision local-revision) (when (y-or-n-p (format "Text is out of sync with pad on the server (revision %s > %s) resync? " remote-revision local-revision)) (etherpad-update etherpad--local-pad-name)) (progn (etherpad--api-set-text etherpad--local-pad-name (buffer-string)) (message "wrote to pad: %s revision %s" etherpad--local-pad-name (etherpad--api-pad-revision etherpad--local-pad-name)) (setq etherpad--local-pad-revision (etherpad--api-pad-revision etherpad--local-pad-name)) (message "new revision? %s" etherpad--local-pad-revision) (rename-buffer (format "%s:%s at %s" etherpad--local-pad-name etherpad--local-pad-revision etherpad-server)) (message "pad has been synced (at revision %s)" etherpad--local-pad-revision))))) (defun etherpad-before-change-function (_begin _end) "Function to run before etherpad update (buffer BEGIN and END). should be specific to minor mode and buffer local." (let* ((remote-revision (etherpad--api-pad-revision etherpad--local-pad-name)) (local-revision etherpad--local-pad-revision)) (when (> remote-revision local-revision) (etherpad-update)))) (defun etherpad-after-change-function (_begin _end _length) "Function to run after buuffer has changed (buffer BEGIN, END & LENGTH). should be specific to minor mode and buffer local." (etherpad-save)) (defun etherpad-autosync-toggle () "Toggle autosync." (interactive) (if etherpad-autosync (progn (setq etherpad-autosync nil) (etherpad-autosync-disable)) (progn (setq etherpad-autosync t) (etherpad-autosync-enable)))) (defun etherpad-autosync-enable () "Enable autosync." (interactive) (message "enabled autosync with etherpad server.") (make-local-variable 'after-change-functions) (make-local-variable 'before-change-functions) (add-hook 'after-change-functions #'etherpad-after-change-function) (add-hook 'before-change-functions #'etherpad-before-change-function)) (defun etherpad-autosync-disable () "Disable autosync." (interactive) (message "disabled autosync with etherpad server.") (remove-hook 'after-change-functions #'etherpad-after-change-function) (remove-hook 'before-change-functions #'etherpad-before-change-function)) (defun etherpad-idlesync-enable () "Sync pad whenever auto-save would." (interactive) (make-local-variable 'auto-save-hook) (make-local-variable 'auto-save-mode) (auto-save-mode t) (add-hook 'auto-save-hook #'etherpad-save)) (defun etherpad-idlesync-disable () "Disable idle syncing." (interactive) (remove-hook 'auto-save-hook #'etherpad-save)) (provide 'etherpad) ;;; etherpad.el ends here