Previewing-mode

A minor mode for running commands every time you save your file.

For example, when writing with knitr, you cah have it automatically knit and reload your web browser after every save.

Use it for Markdown, HTML, LaTeX, sweave, knitr, pic and other markup files and literate programming modes (configuration details forthcoming.)

Use it to automatically run your unit tests.

Supplants the built-in M-x compile functionality by sequencing multiple commands (e.g. process the file and then open the result in the browser,) being easily configurable to select appropriate commands based on mode, filename or other criteria, acting independently per buffer, and paying attention to exit statuses.

Fairly easily configurable to do any build/view process you can phrase in terms of regexps and shell commands. Extensible with Lisp functions as well. Does most of its work asynchronously so you can keep typing away in the foreground.

Installation and configuration

Download and put this in your .emacs.d:

(add-to-path 'load-path "path/to/previewing-mode")
(require 'previewing)

Perhaps you want to have automatic previewing when you work on .Rhtml files. You'd configure a conversion using regexps against the file name to make a command line:

(add-to-list 'previewing-build-command-alist
             `("\\(.*\\)\\.[Rr]\\(html?\\)$" ; match file name
               ("R" "-e"
                ,(concat "library(knitr);"
                         "knit(commandArgs(trailingOnly=TRUE)[[1]],"
                         "     output=commandArgs(trailingOnly=TRUE)[[2]])")
                "\\&" "\\1.\\2")))      ; command args based on match

(add-mode-hook 'html-mode-hook 'previewing-mode)

You can also use file-local veriables to specify preveiw steps for particular files. For more configuration examples see the examples directory.

TODO:

• Default fall back on existing emacs compiling infrastructure
• Maybe a mechanism for asking about overwrites
• Support farming out work to (persistent) inferior shells
• Do async in a less ad hoc way
• Extend "build" and "view" to maybe other verbs? ("test", "tangle", "extract")