allout.el is part of GnuEmacs (and XEmacs, in the edit-utils package). Allout outline mode always runs as a minor mode.

Allout outline mode provides extensive outline formatting and manipulation beyond standard emacs outline mode. It provides for structured editing of outlines, as well as navigation and exposure. It also provides for syntax-sensitive text like programming languages. (For an example, see the allout code itself, which is organized in an allout outline framework.)

In addition to outline navigation and exposure, allout includes:

and many other features.

The most recent version of allout, plus ancillary stuff, is available at the author's site. That also has instructions for getting an addon, allout-widgets, which provides outline structure visual highlighting.

Quick Start

For a detailed overview of Allout features, keystrokes, and configuration, please read the docstring for allout-mode:

     C-h f allout-mode RET

The “Terminology” section is especially helpful for understanding how the package works with your files.

To try it out, visit “allout.el” itself. Then hit

   M-x allout-hide-bodies

and you’ll get an indented outline view of the source code, which happens to be organized in allout-format! Then use C-c [SPC] C-s to Show a topic, and C-c [SPC] C-h to Hide it.

Alternately, if you put the TextCursor on one of the topic bullets, then unmodified ascii keys will have the effect of their ‘C-c’ control-c modified keybindings - ‘n’ to go to the next topic, ‘p’ for previous, ‘i’ to show children, ‘h’ to hide them, etc. Someone spelled out a bunch of the keys, below.

Note: You might have to execute M-x allout-mode to turn on the keybindings.

This is the (old - see just below) documented way of setting it up:

    (require 'allout)
    (outline-init t)

I found I had to use (allout-init t) insteadDamienElmes

(allout-init t) on Gnu Emacs 21.3 gave me an Symbol’s function definition is void: allout-init error but (outline-init t) seems to work thereBrentGoodrick

It depends on the allout version you’re using. Version 2.2 uses allout-init, whereas GNU Emacs 21.4.1 ships with allout version 1.29 which uses outline-initAdamSpiers

To quickly try it out:

  1. eval the above two lines of code
  2. visit allout.el
  3. use C-c C-a C-c C-a (that’s twice) to position your cursor over the first “hot-spot”
  4. now the following keys are active (without C-c prefix):
    b outline-backward-current-level
    f outline-forward-current-level
    h outline-hide-current-subtree
    i outline-show-children
    n outline-next-visible-heading
    o outline-show-current-entry
    p outline-previous-visible-heading
    s outline-show-current-subtree
    u outline-up-current-level

Those are the commonly used keys - any C-c modified allout keybinding should work without the C-c in allout-mode, when the cursor is over a bullet.

Fontifying your headers

By default, allout mode does not fontify the buffer. To get Font Lock to work put the following into your .emacs (adapted from the standard outline mode):

(defvar rf-allout-font-lock-keywords
    ;; Highlight headings according to the level.
    (eval . (list (concat "^\\(" outline-regexp "\\).+")
		0 '(or (cdr (assq (outline-depth)
				  '((1 . font-lock-function-name-face)
				    (2 . font-lock-variable-name-face)
				    (3 . font-lock-keyword-face)
				    (4 . font-lock-builtin-face)
				    (5 . font-lock-comment-face)
				    (6 . font-lock-constant-face)
				    (7 . font-lock-type-face)
				    (8 . font-lock-string-face))))
		nil t)))
  "Additional expressions to highlight in Outline mode.")

;; add font-lock to allout mode
(defun rf-allout-font-lock-hook ()
  (set (make-local-variable 'font-lock-defaults)
       '(rf-allout-font-lock-keywords t nil nil outline-back-to-current-heading)))

(add-hook 'outline-mode-hook 'rf-allout-font-lock-hook)

With emacs and allout version 1.45 I (Friedel) have to replace allout-regexp, allout-depth, allout-back-to-current-heading and allout-mode-hook for their outline-prefixed counterparts to get the above lisp-snippet to work.

I (Gallagher) was unable to get the above code working with Xemacs 21.4.13 with the allout.el that comes with edit-utils 2.22, I think because that version of allout doesn’t expose its regexps directly. But the following code will highlight headers, even if it doesn’t change colors based on outline depth. It only works if you have set outline-stylish-prefixes to nil (i.e., the “*” or “. *” style header prefixes):

(defun my-outline-highlight () (interactive) (setq font-lock-keywords (list '("^\\(\\* \\|\\(\\. *\\* \\)\\)\\(.*\\)$" 3 font-lock-keyword-face)))) (add-hook 'outline-mode-hook 'my-outline-highlight) (add-hook 'outline-mode-hook 'font-lock-mode)

I modified the above code to be a bit better-behaved, and got basic outline header fontification to work on CvsEmacs. I’m trying to hack this further so that it obeys mode-specific and file-specific format settings. --DavidOtoole

(defun dto/allout-highlight-headings ()
  (font-lock-add-keywords nil '(("^\\(\\* \\|\\(\\. *\\* \\)\\)\\(.*\\)$" 3 font-lock-keyword-face t))))
(add-hook 'allout-mode-hook 'dto/allout-highlight-headings)

Is it possible to show only the last child? If I have:

* A
.* a
   a stuff
.* b
   b stuff
.* c
   c stuff

I know how to get:

* A
.* a
.* b
.* c
   c stuff

but I want to see:

* A
.* c
   c stuff

Sort of. Allout aims for exposure coherence, so in the steady state, all sibling topics are exposed or hidden as a group. However, during incremental search it will show just what you’re asking, if you collapse topic A and do an incremental search for c stuff. The siblings will be exposed if you end the search there, or the A topic will be recollapsed if you abort the search or continue it past that point. KenManheimer

Is it possible to reconcile allout with auto-indent modes (i.e. c-mode, php-mode, etc)? I got allout mode to auto-start in c-mode and “work” with c style comments with the following:

(make-local-variable 'allout-primary-bullet)
(make-local-variable 'comment-start)
(defun my-c-mode-allout-hook()
  (setq allout-primary-bullet "\/\/\/_*")
  (setq comment-start "\/")
(add-hook 'c-mode-hook 'my-c-mode-allout-hook)

This works wonderfully if I just want to give a top-level header to each function, but making sub-trees in a function body fails because c-mode auto-indents, but allout doesn’t allow leading whitespace before topic headers.

The solution I would like to see is:

extend allout-mode to ignore whitespace before topic headers.  I.e., 
is treated as being the same as

There could be an option made called “allow-leading-whitespace-in-header”. Setting it non-nil would enable the specified behavior, and could be automatically set if the buffer is source code, similar to how the following from allout.el sets a variable if the buffer is text (i.e. not source code): (defcustom allout-reindent-bodies (if allout-use-hanging-indents 'text)

XEmacs 21.4 (patch 15) includes allout.el as well TerrenceBrannon

Yes, it’s in the edit-utils package. – AdrianAichner

XEmacs 21.4 (p. 18) includes allout.el but in version 1.1; site says to activate allout by (require 'outline "allout") and then to fontify using rf-allout-font-lock-keywords above. All that works fine. OTOH, version 2.2 of allout.el from MyriadCity uses local-variable-p without the (supposedly optional) second argument, and so is in a form XEmacs can’t use. Am I missing something obvious, is there an easy fix if I want to use allout 2.2 in XEmacs? --DannyQuah 2006.08.28 1717h GMT

Trying in XEmacs 21.4 (p. 13) Received wrong-type-argument stringp error; has anyone seen this?

    ;; repro: (1) eval this bootstrap code to init allout
    (require 'allout)
     (allout-init t) 
    (substitute-key-definition 'end-of-line 'move-end-of-line global-map)
    (substitute-key-definition 'beginning-of-line 'move-beginning-of-line global-map)
    ;;  then (2) load in allout.el file  then (3) do the M-x allout-hide-bodies
    ;;  which generates this stack dump:
    Debugger entered--Lisp error: (wrong-type-argument stringp nil)
      ad-Orig-re-search-forward(nil nil 0 nil nil)
      re-search-forward(nil nil 0)
      (if (re-search-forward allout-line-boundary-regexp nil 0) (progn (allout-prefix-data) (and ... ...) (goto-char allout-recent-prefix-beginning)))
      (when (re-search-forward allout-line-boundary-regexp nil 0) (allout-prefix-data) (and (allout-do-doublecheck) (allout-aberrant-container-p)) (goto-char allout-recent-prefix-beginning))
      (if (allout-next-heading) (goto-char (1- allout-recent-prefix-beginning)))
      (allout-flag-region (point) (allout-end-of-entry) t)
      (while (not (eobp)) (end-of-line) (allout-flag-region (point) (allout-end-of-entry) t) (if (not ...) (forward-char ...)))
      (let ((inhibit-field-text-motion t)) (while (not ...) (end-of-line) (allout-flag-region ... ... t) (if ... ...)))
      (save-restriction (narrow-to-region start end) (goto-char (point-min)) (let (...) (while ... ... ... ...)))
      (save-excursion (save-restriction (narrow-to-region start end) (goto-char ...) (let ... ...)))
      allout-hide-region-body(1 291869)
      (lambda nil "Hide all of buffer except headings." (interactive) (allout-hide-region-body (point-min) (point-max)))()
      command-execute(allout-hide-bodies t)
 --TomPopovich 2007.01.17

Encryption support

As of Emacs 22, Emacs’ alternative, comprehensive outline mode, Allout, provides for easy gpg encryption/decryption of topics. Major features:

Allout encryption requires installation of gpg on your system, but otherwise depends only on packages that come with Emacs.

(Allout non-encryption functionality is not disrupted by the absence of gpg, and has extensive outline editing features as well as navigation features, including topic-oriented promotion, demotion, cut and paste, incremental search with dynamic exposure and re-concealment, automatic topic numbering, “hot-spot” navigation for easy outline browsing, TeX formatting, and much much more.)

See AutoEncryption.

Is there a way to export an outlined content to HTML? Like in ORG mode, or better htmlize.el but with HTML headers and maybe contents on top of the page?

CategoryOutline KenManheimer