lisp/files-x.el

   1 ;;; files-x.el --- extended file handling commands
   2
   3 ;; Copyright (C) 2009-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Juri Linkov <juri@jurta.org>
   6 ;; Maintainer: emacs-devel@gnu.org
   7 ;; Keywords: files
   8 ;; Package: emacs
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; This file defines additional infrequently used file- and
  28 ;; directory-handling commands that should not be in files.el
  29 ;; to not make the dumped image bigger.
  30
  31 ;;; Code:
  32
  33 \f
  34 ;;; Commands to add/delete file-local/directory-local variables.
  35
  36 (defun read-file-local-variable (prompt)
  37   "Read file-local variable using PROMPT and completion.
  38 Intended to be used in the `interactive' spec of
  39 `add-file-local-variable', `delete-file-local-variable',
  40 `add-dir-local-variable', `delete-dir-local-variable'."
  41   (let* ((default (variable-at-point))
  42          (default (and (symbolp default) (boundp default)
  43                        (symbol-name default)))
  44          (variable
  45           (completing-read
  46            (if default
  47                (format "%s (default %s): " prompt default)
  48              (format "%s: " prompt))
  49            obarray
  50            (lambda (sym)
  51              (or (custom-variable-p sym)
  52                  (get sym 'safe-local-variable)
  53                  (memq sym '(mode eval coding unibyte))))
  54            nil nil nil default nil)))
  55     (and (stringp variable) (intern variable))))
  56
  57 (defun read-file-local-variable-value (variable)
  58   "Read value of file-local VARIABLE using completion.
  59 Intended to be used in the `interactive' spec of
  60 `add-file-local-variable' and `add-dir-local-variable'."
  61   (cond
  62    ((eq variable 'mode)
  63     (let* ((default (and (symbolp major-mode) (symbol-name major-mode)))
  64            (value
  65             (completing-read
  66              (if default
  67                  (format "Add %s with value (default %s): " variable default)
  68                (format "Add %s with value: " variable))
  69              obarray
  70              (lambda (sym)
  71                (string-match-p "-mode\\'" (symbol-name sym)))
  72              nil nil nil default nil)))
  73       (and (stringp value)
  74            (intern (replace-regexp-in-string "-mode\\'" "" value)))))
  75    ((eq variable 'eval)
  76     (read--expression (format "Add %s with expression: " variable)))
  77    ((eq variable 'coding)
  78     (let ((default (and (symbolp buffer-file-coding-system)
  79                         (symbol-name buffer-file-coding-system))))
  80       (read-coding-system
  81        (if default
  82            (format "Add %s with value (default %s): " variable default)
  83          (format "Add %s with value: " variable))
  84        default)))
  85    (t
  86     (let ((default (format "%S"
  87                            (cond ((eq variable 'unibyte) t)
  88                                  ((boundp variable)
  89                                   (symbol-value variable)))))
  90           (minibuffer-completing-symbol t))
  91       (read-from-minibuffer (format "Add %s with value: " variable)
  92                             nil read-expression-map t
  93                             'set-variable-value-history
  94                             default)))))
  95
  96 (defun read-file-local-variable-mode ()
  97   "Read per-directory file-local variable's mode using completion.
  98 Intended to be used in the `interactive' spec of
  99 `add-dir-local-variable', `delete-dir-local-variable'."
 100   (let* ((default (and (symbolp major-mode) (symbol-name major-mode)))
 101          (mode
 102           (completing-read
 103            (if default
 104                (format "Mode or subdirectory (default %s): " default)
 105              (format "Mode or subdirectory: "))
 106            obarray
 107            (lambda (sym)
 108              (and (string-match-p "-mode\\'" (symbol-name sym))
 109                   (not (or (memq sym minor-mode-list)
 110                            (string-match-p "-minor-mode\\'"
 111                                            (symbol-name sym))))))
 112            nil nil nil default nil)))
 113     (cond
 114      ((equal mode "nil") nil)
 115      ((and (stringp mode) (fboundp (intern mode))) (intern mode))
 116      (t mode))))
 117
 118 (defun modify-file-local-variable-message (variable value op)
 119   (let* ((not-value (make-symbol ""))
 120          (old-value (cond ((eq variable 'mode)
 121                            major-mode)
 122                           ((eq variable 'coding)
 123                            buffer-file-coding-system)
 124                           (t (if (and (symbolp variable)
 125                                       (boundp variable))
 126                                  (symbol-value variable)
 127                                not-value))))
 128          (new-value (if (eq op 'delete)
 129                         (cond ((eq variable 'mode)
 130                                (default-value 'major-mode))
 131                               ((eq variable 'coding)
 132                                (default-value 'buffer-file-coding-system))
 133                               (t (if (and (symbolp variable)
 134                                           (default-boundp variable))
 135                                      (default-value variable)
 136                                    not-value)))
 137                       (cond ((eq variable 'mode)
 138                              (let ((string (format "%S" value)))
 139                                (if (string-match-p "-mode\\'" string)
 140                                    value
 141                                  (intern (concat string "-mode")))))
 142                             (t value)))))
 143     (when (or (eq old-value not-value)
 144               (eq new-value not-value)
 145               (not (equal old-value new-value)))
 146       (message "%s" (substitute-command-keys
 147                      "For this change to take effect revisit file using \\[revert-buffer]")))))
 148
 149 (defun modify-file-local-variable (variable value op &optional interactive)
 150   "Modify file-local VARIABLE in Local Variables depending on operation OP.
 151
 152 If OP is `add-or-replace' then delete all existing settings of
 153 VARIABLE (except `mode' and `eval') and add a new file-local VARIABLE
 154 with VALUE to the Local Variables list.
 155
 156 If there is no Local Variables list in the current file buffer and OP
 157 is not `delete' then this function adds the first line containing the
 158 string `Local Variables:' and the last line containing the string `End:'.
 159
 160 If OP is `delete' then delete all existing settings of VARIABLE
 161 from the Local Variables list ignoring the input argument VALUE."
 162   (catch 'exit
 163     (let ((beg (point)) end replaced-pos)
 164       (unless enable-local-variables
 165         (throw 'exit (message "File-local variables are disabled")))
 166
 167       ;; Look for "Local variables:" line in last page.
 168       (widen)
 169       (goto-char (point-max))
 170       (search-backward "\n\^L" (max (- (point-max) 3000) (point-min)) 'move)
 171
 172       ;; Add "Local variables:" list if not found.
 173       (unless (let ((case-fold-search t))
 174                 (search-forward "Local Variables:" nil t))
 175
 176         ;; Don't add "Local variables:" list for the deletion operation.
 177         (when (eq op 'delete)
 178           (throw 'exit (progn (goto-char beg)
 179                               (message "Local Variables not found"))))
 180
 181         (goto-char (point-max))
 182         (let ((comment-style 'plain)
 183               (comment-start (or comment-start ";; ")))
 184           (comment-region
 185            (prog1 (setq beg (point))
 186              (insert "\nLocal Variables:\nEnd:\n"))
 187            (point)))
 188
 189         (unless (let ((case-fold-search t))
 190                   (goto-char beg)
 191                   (search-forward "Local Variables:" nil t))
 192           (throw 'exit (message "Can't add file-local variables"))))
 193
 194       ;; prefix is what comes before "local variables:" in its line.
 195       ;; suffix is what comes after "local variables:" in its line.
 196       (let* ((prefix (buffer-substring (line-beginning-position)
 197                                        (match-beginning 0)))
 198              (suffix (buffer-substring (point) (line-end-position)))
 199              (prefix-re (concat "^" (regexp-quote prefix)))
 200              (suffix-re (concat (regexp-quote suffix) "$")))
 201
 202         ;; Find or add missing "End:".
 203         (forward-line 1)
 204         (setq beg (point))
 205         (save-excursion
 206           (unless (let ((case-fold-search t))
 207                     (re-search-forward
 208                      (concat prefix-re "[ \t]*End:[ \t]*" suffix-re)
 209                      nil t))
 210             (save-excursion
 211               (insert (format "%sEnd:%s\n" prefix suffix))))
 212           (beginning-of-line)
 213           (setq end (point-marker)))
 214
 215         ;; Find and delete all existing variable/value pairs.
 216         (when (member op '(add-or-replace delete))
 217           (if (and (eq op 'add-or-replace) (memq variable '(mode eval)))
 218               (goto-char end)
 219             (goto-char beg)
 220             (while (re-search-forward
 221                     (format "%s%S:.*%s" prefix-re variable suffix-re) end t)
 222               (delete-region (match-beginning 0) (1+ (match-end 0)))
 223               (setq replaced-pos (point)))))
 224
 225         ;; Add a new variable/value pair.  Add `mode' to the start, add new
 226         ;; variable to the end, and add a replaced variable to its last location.
 227         (when (eq op 'add-or-replace)
 228           (cond
 229            ((eq variable 'mode) (goto-char beg))
 230            ((null replaced-pos) (goto-char end))
 231            (replaced-pos (goto-char replaced-pos)))
 232           (insert (format "%s%S: %S%s\n" prefix variable value suffix))))
 233
 234       (when interactive
 235         (modify-file-local-variable-message variable value op)))))
 236
 237 ;;;###autoload
 238 (defun add-file-local-variable (variable value &optional interactive)
 239   "Add file-local VARIABLE with its VALUE to the Local Variables list.
 240
 241 This command deletes all existing settings of VARIABLE (except `mode'
 242 and `eval') and adds a new file-local VARIABLE with VALUE to the
 243 Local Variables list.
 244
 245 If there is no Local Variables list in the current file buffer
 246 then this function adds the first line containing the string
 247 `Local Variables:' and the last line containing the string `End:'."
 248   (interactive
 249    (let ((variable (read-file-local-variable "Add file-local variable")))
 250      ;; Error before reading value.
 251      (if (equal variable 'lexical-binding)
 252          (user-error "The `%s' variable must be set at the start of the file"
 253                      variable))
 254      (list variable (read-file-local-variable-value variable) t)))
 255   (if (equal variable 'lexical-binding)
 256       (user-error "The `%s' variable must be set at the start of the file"
 257                   variable))
 258   (modify-file-local-variable variable value 'add-or-replace interactive))
 259
 260 ;;;###autoload
 261 (defun delete-file-local-variable (variable &optional interactive)
 262   "Delete all settings of file-local VARIABLE from the Local Variables list."
 263   (interactive
 264    (list (read-file-local-variable "Delete file-local variable") t))
 265   (modify-file-local-variable variable nil 'delete interactive))
 266
 267 (defun modify-file-local-variable-prop-line (variable value op &optional interactive)
 268   "Modify file-local VARIABLE in the -*- line depending on operation OP.
 269
 270 If OP is `add-or-replace' then delete all existing settings of
 271 VARIABLE (except `mode' and `eval') and add a new file-local VARIABLE
 272 with VALUE to the -*- line.
 273
 274 If there is no -*- line at the beginning of the current file buffer
 275 and OP is not `delete' then this function adds the -*- line.
 276
 277 If OP is `delete' then delete all existing settings of VARIABLE
 278 from the -*- line ignoring the input argument VALUE."
 279   (catch 'exit
 280     (let ((beg (point)) end replaced-pos)
 281       (unless enable-local-variables
 282         (throw 'exit (message "File-local variables are disabled")))
 283
 284       ;; Find the -*- line at the beginning of the current buffer.
 285       (widen)
 286       (goto-char (point-min))
 287       (setq end (set-auto-mode-1))
 288
 289       (if end
 290           (setq beg (point-marker) end (copy-marker end))
 291
 292         ;; Add the -*- line if not found.
 293         ;; Don't add the -*- line for the deletion operation.
 294         (when (eq op 'delete)
 295           (throw 'exit (progn (goto-char beg)
 296                               (message "The -*- line not found"))))
 297
 298         (goto-char (point-min))
 299
 300         ;; Skip interpreter magic line "#!" or XML declaration.
 301         (when (or (looking-at file-auto-mode-skip)
 302                   (looking-at "<\\?xml[^>\n]*>$"))
 303           (forward-line 1))
 304
 305         (let ((comment-style 'plain)
 306               (comment-start (or comment-start ";;; "))
 307               (line-beg (line-beginning-position))
 308               (ce nil))
 309           (comment-normalize-vars)
 310           ;; If the first line contains a comment.
 311           (if (save-excursion
 312                 (and (looking-at comment-start-skip)
 313                      (goto-char (match-end 0))
 314                      (re-search-forward comment-end-skip)
 315                      (goto-char (match-beginning 0))
 316                      ;; Still on the same line?
 317                      (equal line-beg (line-beginning-position))
 318                      (setq ce (point))))
 319               ;; Add local variables to the end of the existing comment.
 320               (progn
 321                 (goto-char ce)
 322                 (insert "  -*-")
 323                 (setq beg (point-marker))
 324                 (setq end (point-marker))
 325                 (insert "-*-"))
 326             ;; Otherwise, add a new comment before the first line.
 327             (comment-region
 328              (prog1 (point)
 329                (insert "-*-")
 330                (setq beg (point-marker))
 331                (setq end (point-marker))
 332                (insert "-*-\n"))
 333              (point)))))
 334
 335       (cond
 336        ((looking-at "[ \t]*\\([^ \t\n\r:;]+\\)\\([ \t]*-\\*-\\)")
 337         ;; Simple form: "-*- MODENAME -*-".
 338         (if (eq variable 'mode)
 339             ;; Replace or delete MODENAME
 340             (progn
 341               (when (member op '(add-or-replace delete))
 342                 (delete-region (match-beginning 1) (match-end 1)))
 343               (when (eq op 'add-or-replace)
 344                 (goto-char (match-beginning 1))
 345                 (insert (format "%S" value))))
 346           ;; Else, turn `MODENAME' into `mode:MODENAME'
 347           ;; and add `VARIABLE: VALUE;'
 348           (goto-char (match-beginning 2))
 349           (insert (format "; %S: %S; " variable value))
 350           (goto-char (match-beginning 1))
 351           (insert " mode: ")))
 352
 353        (t
 354         ;; Hairy form: '-*-' [ <variable> ':' <value> ';' ]* '-*-'
 355         ;; Find and delete all existing variable/value pairs.
 356         (when (member op '(add-or-replace delete))
 357           (if (and (eq op 'add-or-replace) (memq variable '(mode eval)))
 358               (goto-char end)
 359             (goto-char beg)
 360             (while (< (point) end)
 361               (or (looking-at "[ \t]*\\([^ \t\n:]+\\)[ \t]*:[ \t]*")
 362                   (throw 'exit (message "Malformed -*- line")))
 363               (goto-char (match-end 0))
 364               (let ((key (intern (match-string 1))))
 365                 (save-restriction
 366                   (narrow-to-region (point) end)
 367                   (let ((read-circle nil))
 368                     (read (current-buffer))))
 369                 (skip-chars-forward " \t;")
 370                 (when (eq key variable)
 371                   (delete-region (match-beginning 0) (point))
 372                   (setq replaced-pos (point)))))))
 373         ;; Add a new variable/value pair.  Add `mode' to the start, add new
 374         ;; variable to the end, and add a replaced variable to its last location.
 375         (when (eq op 'add-or-replace)
 376           (cond
 377            ((eq variable 'mode) (goto-char beg))
 378            ((null replaced-pos) (goto-char end))
 379            (replaced-pos (goto-char replaced-pos)))
 380           (if (and (not (eq (char-before) ?\;))
 381                    (not (equal (point) (marker-position beg)))
 382                    ;; When existing `-*- -*-' is empty, beg > end.
 383                    (not (> (marker-position beg) (marker-position end))))
 384               (insert ";"))
 385           (unless (eq (char-before) ?\s) (insert " "))
 386           (insert (format "%S: %S;" variable value))
 387           (unless (eq (char-after) ?\s) (insert " ")))))
 388
 389       (when interactive
 390         (modify-file-local-variable-message variable value op)))))
 391
 392 ;;;###autoload
 393 (defun add-file-local-variable-prop-line (variable value &optional interactive)
 394   "Add file-local VARIABLE with its VALUE to the -*- line.
 395
 396 This command deletes all existing settings of VARIABLE (except `mode'
 397 and `eval') and adds a new file-local VARIABLE with VALUE to
 398 the -*- line.
 399
 400 If there is no -*- line at the beginning of the current file buffer
 401 then this function adds it."
 402   (interactive
 403    (let ((variable (read-file-local-variable "Add -*- file-local variable")))
 404      (list variable (read-file-local-variable-value variable) t)))
 405   (modify-file-local-variable-prop-line variable value 'add-or-replace interactive))
 406
 407 ;;;###autoload
 408 (defun delete-file-local-variable-prop-line (variable &optional interactive)
 409   "Delete all settings of file-local VARIABLE from the -*- line."
 410   (interactive
 411    (list (read-file-local-variable "Delete -*- file-local variable") t))
 412   (modify-file-local-variable-prop-line variable nil 'delete interactive))
 413
 414 (defvar auto-insert) ; from autoinsert.el
 415
 416 (defun modify-dir-local-variable (mode variable value op)
 417   "Modify directory-local VARIABLE in .dir-locals.el depending on operation OP.
 418
 419 If OP is `add-or-replace' then delete all existing settings of
 420 VARIABLE (except `mode' and `eval') and add a new directory-local VARIABLE
 421 with VALUE to the MODE alist where MODE can be a mode name symbol or
 422 a subdirectory name.
 423
 424 If .dir-locals.el was not found and OP is not `delete' then create
 425 this file in the current directory.
 426
 427 If OP is `delete' then delete all existing settings of VARIABLE
 428 from the MODE alist ignoring the input argument VALUE."
 429   (catch 'exit
 430     (unless enable-local-variables
 431       (throw 'exit (message "Directory-local variables are disabled")))
 432     (let* ((dir-or-cache (and (buffer-file-name)
 433                               (not (file-remote-p (buffer-file-name)))
 434                               (dir-locals-find-file (buffer-file-name))))
 435            (variables-file
 436             ;; If there are several .dir-locals, the user probably
 437             ;; wants to edit the last one (the highest priority).
 438             (cond ((stringp dir-or-cache)
 439                    (car (last (dir-locals--all-files dir-or-cache))))
 440                   ((consp dir-or-cache) ; result from cache
 441                    ;; If cache element has an mtime, assume it came
 442                    ;; from a file.  Otherwise, assume it was set
 443                    ;; directly.
 444                    (if (nth 2 dir-or-cache)
 445                        (car (last (dir-locals--all-files (car dir-or-cache))))
 446                      (cadr dir-or-cache)))
 447                   ;; Try to make a proper file-name.
 448                   (t (expand-file-name dir-locals-file))))
 449            variables)
 450       ;; I can't be bothered to handle this case right now.
 451       ;; Dir locals were set directly from a class.  You need to
 452       ;; directly modify the class in dir-locals-class-alist.
 453       (and variables-file (not (stringp variables-file))
 454            (throw 'exit (message "Directory locals were not set from a file")))
 455       ;; Don't create ".dir-locals.el" for the deletion operation.
 456       (and (eq op 'delete)
 457            (or (not variables-file)
 458                (not (file-exists-p variables-file)))
 459            (throw 'exit (message "No .dir-locals.el file was found")))
 460       (let ((auto-insert nil))
 461         (find-file variables-file))
 462       (widen)
 463       (goto-char (point-min))
 464
 465       ;; Read alist of directory-local variables.
 466       (ignore-errors
 467         (delete-region
 468          (prog1 (point)
 469            (setq variables (let ((read-circle nil))
 470                              (read (current-buffer)))))
 471          (point)))
 472
 473       ;; Add or replace variable in alist of directory-local variables.
 474       (let ((mode-assoc (assoc mode variables)))
 475         (if mode-assoc
 476             (setq variables
 477                   (cons (cons mode
 478                               (if (eq op 'delete)
 479                                   (assq-delete-all variable (cdr mode-assoc))
 480                                 (cons
 481                                  (cons variable value)
 482                                  (if (memq variable '(mode eval))
 483                                      (cdr mode-assoc)
 484                                    (assq-delete-all variable (cdr mode-assoc))))))
 485                         (assq-delete-all mode variables)))
 486           (setq variables
 487                 (cons `(,mode . ((,variable . ,value)))
 488                       variables))))
 489
 490       ;; Insert modified alist of directory-local variables.
 491       (insert ";;; Directory Local Variables\n")
 492       (insert ";;; For more information see (info \"(emacs) Directory Variables\")\n\n")
 493       (pp (sort variables
 494                 (lambda (a b)
 495                   (cond
 496                    ((null (car a)) t)
 497                    ((null (car b)) nil)
 498                    ((and (symbolp (car a)) (stringp (car b))) t)
 499                    ((and (symbolp (car b)) (stringp (car a))) nil)
 500                    (t (string< (car a) (car b))))))
 501           (current-buffer)))))
 502
 503 ;;;###autoload
 504 (defun add-dir-local-variable (mode variable value)
 505   "Add directory-local VARIABLE with its VALUE and MODE to .dir-locals.el."
 506   (interactive
 507    (let (variable)
 508      (list
 509       (read-file-local-variable-mode)
 510       (setq variable (read-file-local-variable "Add directory-local variable"))
 511       (read-file-local-variable-value variable))))
 512   (modify-dir-local-variable mode variable value 'add-or-replace))
 513
 514 ;;;###autoload
 515 (defun delete-dir-local-variable (mode variable)
 516   "Delete all MODE settings of file-local VARIABLE from .dir-locals.el."
 517   (interactive
 518    (list
 519     (read-file-local-variable-mode)
 520     (read-file-local-variable "Delete directory-local variable")))
 521   (modify-dir-local-variable mode variable nil 'delete))
 522
 523 ;;;###autoload
 524 (defun copy-file-locals-to-dir-locals ()
 525   "Copy file-local variables to .dir-locals.el."
 526   (interactive)
 527   (dolist (elt file-local-variables-alist)
 528     (unless (assq (car elt) dir-local-variables-alist)
 529       (add-dir-local-variable major-mode (car elt) (cdr elt)))))
 530
 531 ;;;###autoload
 532 (defun copy-dir-locals-to-file-locals ()
 533   "Copy directory-local variables to the Local Variables list."
 534   (interactive)
 535   (dolist (elt dir-local-variables-alist)
 536     (add-file-local-variable (car elt) (cdr elt))))
 537
 538 ;;;###autoload
 539 (defun copy-dir-locals-to-file-locals-prop-line ()
 540   "Copy directory-local variables to the -*- line."
 541   (interactive)
 542   (dolist (elt dir-local-variables-alist)
 543     (add-file-local-variable-prop-line (car elt) (cdr elt))))
 544
 545 \f
 546 ;;; connection-local variables.
 547
 548 ;;;###autoload
 549 (defvar enable-connection-local-variables t
 550   "Non-nil means enable use of connection-local variables.")
 551
 552 (defvar connection-local-variables-alist nil
 553   "Alist of connection-local variable settings in the current buffer.
 554 Each element in this list has the form (VAR . VALUE), where VAR
 555 is a connection-local variable (a symbol) and VALUE is its value.
 556 The actual value in the buffer may differ from VALUE, if it is
 557 changed by the user.")
 558 (make-variable-buffer-local 'connection-local-variables-alist)
 559 (setq ignored-local-variables
 560       (cons 'connection-local-variables-alist ignored-local-variables))
 561
 562 (defvar connection-local-class-alist '()
 563   "Alist mapping connection-local variable classes (symbols) to variable lists.
 564 Each element in this list has the form (CLASS VARIABLES).
 565 CLASS is the name of a variable class (a symbol).
 566 VARIABLES is a list that declares connection-local variables for
 567 CLASS.  An element in VARIABLES is an alist whose elements are of
 568 the form (VAR . VALUE).")
 569
 570 (defvar connection-local-criteria-alist '()
 571   "Alist mapping criteria to connection-local variable classes (symbols).
 572 Each element in this list has the form (CRITERIA CLASSES).
 573 CRITERIA is either a regular expression identifying a remote
 574 server, or a function with one argument IDENTIFICATION, which
 575 returns non-nil when a remote server shall apply CLASS'es
 576 variables.  If CRITERIA is nil, it always applies.
 577 CLASSES is a list of variable classes (symbols).")
 578
 579 (defsubst connection-local-get-classes (criteria &optional identification)
 580   "Return the connection-local classes list for CRITERIA.
 581 CRITERIA is either a regular expression identifying a remote
 582 server, or a function with one argument IDENTIFICATION, which
 583 returns non-nil when a remote server shall apply CLASS'es
 584 variables.  If CRITERIA is nil, it always applies.
 585 If IDENTIFICATION is non-nil, CRITERIA must be nil, or match
 586 IDENTIFICATION accordingly."
 587   (and (cond ((null identification))
 588              ((not (stringp identification))
 589               (error "Wrong identification `%s'" identification))
 590              ((null criteria))
 591              ((stringp criteria) (string-match criteria identification))
 592              ((functionp criteria) (funcall criteria identification))
 593              (t  "Wrong criteria `%s'" criteria))
 594        (cdr (assoc criteria connection-local-criteria-alist))))
 595
 596 ;;;###autoload
 597 (defun connection-local-set-classes (criteria &rest classes)
 598   "Add CLASSES for remote servers.
 599 CRITERIA is either a regular expression identifying a remote
 600 server, or a function with one argument IDENTIFICATION, which
 601 returns non-nil when a remote server shall apply CLASS'es
 602 variables.  If CRITERIA is nil, it always applies.
 603 CLASSES are the names of a variable class (a symbol).
 604
 605 When a connection to a remote server is opened and CRITERIA
 606 matches to that server, the connection-local variables from CLASSES
 607 are applied to the corresponding process buffer.  The variables
 608 for a class are defined using `connection-local-set-class-variables'."
 609   (unless (or (null criteria) (stringp criteria) (functionp criteria))
 610     (error "Wrong criteria `%s'" criteria))
 611   (dolist (class classes)
 612     (unless (assq class connection-local-class-alist)
 613       (error "No such class `%s'" (symbol-name class))))
 614   (let ((slot (assoc criteria connection-local-criteria-alist)))
 615     (if slot
 616         (setcdr slot (delete-dups (append (cdr slot) classes)))
 617       (setq connection-local-criteria-alist
 618             (cons (cons criteria (delete-dups classes))
 619                   connection-local-criteria-alist)))))
 620
 621 (defsubst connection-local-get-class-variables (class)
 622   "Return the connection-local variable list for CLASS."
 623   (cdr (assq class connection-local-class-alist)))
 624
 625 ;;;###autoload
 626 (defun connection-local-set-class-variables (class variables)
 627   "Map the symbol CLASS to a list of variable settings.
 628 VARIABLES is a list that declares connection-local variables for
 629 the class.  An element in VARIABLES is an alist whose elements
 630 are of the form (VAR . VALUE).
 631
 632 When a connection to a remote server is opened, the server's
 633 classes are found.  A server may be assigned a class using
 634 `connection-local-set-class'.  Then variables are set in the
 635 server's process buffer according to the VARIABLES list of the
 636 class.  The list is processed in order."
 637   (setf (alist-get class connection-local-class-alist) variables))
 638
 639 (defun hack-connection-local-variables ()
 640   "Read per-connection local variables for the current buffer.
 641 Store the connection-local variables in `connection-local-variables-alist'.
 642
 643 This does nothing if `enable-connection-local-variables' is nil."
 644   (let ((identification (file-remote-p default-directory)))
 645     (when (and enable-connection-local-variables identification)
 646       ;; Loop over criteria.
 647       (dolist (criteria (mapcar 'car connection-local-criteria-alist))
 648         ;; Filter classes which map identification.
 649         (dolist (class (connection-local-get-classes criteria identification))
 650           ;; Loop over variables.
 651           (dolist (variable (connection-local-get-class-variables class))
 652             (unless (assq (car variable) connection-local-variables-alist)
 653               (push variable connection-local-variables-alist))))))))
 654
 655 ;;;###autoload
 656 (defun hack-connection-local-variables-apply ()
 657  "Apply connection-local variables identified by `default-directory'.
 658 Other local variables, like file-local and dir-local variables,
 659 will not be changed."
 660  (hack-connection-local-variables)
 661  (let ((file-local-variables-alist
 662         (copy-tree connection-local-variables-alist)))
 663    (hack-local-variables-apply)))
 664
 665 ;;;###autoload
 666 (defmacro with-connection-local-classes (classes &rest body)
 667   "Apply connection-local variables according to CLASSES in current buffer.
 668 Execute BODY, and unwind connection local variables."
 669   (declare (indent 1) (debug t))
 670   `(let ((enable-connection-local-variables t)
 671          (old-buffer-local-variables (buffer-local-variables))
 672          connection-local-variables-alist connection-local-criteria-alist)
 673      (apply 'connection-local-set-classes "" ,classes)
 674      (hack-connection-local-variables-apply)
 675      (unwind-protect
 676          (progn ,@body)
 677        ;; Cleanup.
 678        (dolist (variable connection-local-variables-alist)
 679          (let ((elt (assq (car variable) old-buffer-local-variables)))
 680            (if elt
 681                (set (make-local-variable (car elt)) (cdr elt))
 682            (kill-local-variable (car variable))))))))
 683
 684 \f
 685
 686 (provide 'files-x)
 687
 688 ;;; files-x.el ends here