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Dieter [dee-ter] is a clojure interpretation of the ruby Sprockets library.


Dieter provides you with a ring middleware which will compile certain static assets. Currently it supports concatenating javascript and CSS files, compiling LESS CSS, CoffeeScript and Haml-coffee. In addition it minifies javascript using the Google Closure compiler.

Add dieter as a dependency in leiningen

[dieter "0.4.1"]

Insert it into your ring middleware stack

(-> app
    (asset-pipeline config-options))

Or if you use noir

(server/add-middleware asset-pipeline config-options)

Concatenation of assets is handled by a Dieter manifest file. A manifest is a file whose name ends in .dieter and whose contents are a clojure vector of file names / directories to concatenate.

For example, a file named assets/javascripts/app.js.dieter with the following contents:


Dieter would look for base.js in the same directory, and then concatenate each file from the lib and models directories.


In order to include links to your assets you may use the link-to-asset function.

(link-to-asset "stylesheets/reset.css" config-options)
(link-to-asset "javascripts/app.js.dieter" config-options)

Configuration Options

:engine     :rhino                  ; defaults to :rhino; :v8 is much much faster
:compress   false                   ; minify using Google Closure Compiler & Less compression
:asset-roots ["resources"]          ; must have a folder called 'assets'. Searched for assets in the order listed.
:cache-root "resources/asset-cache" ; compiled assets are cached here
:cache-mode :development            ; or :production. :development disables cacheing
:log-level  :normal                 ; or :quiet
:precompiles ["./assets/myfile.js.dieter"] ; list of files for `lein dieter-precompile` to precompile. If left blank (the default), all files will be precompiled, and errors will be ignored.

Dieter checks for your assets in [asset-root]/assets. Compiled assets are always written to the cache-root. In production mode this means that the cached assets are served from the cache. However development-mode assets are always regenerated.

Note you need to pass your config options to asset-pipeline as well as link-to-asset.


It is easy to add new preprocessors to dieter. Each preprocessor (CoffeeScript, HamlCoffee, etc) uses the default library for that language, hooked up to dieter using the Rhino JavaScript library. See dieter-core/src/dieter/assets/ for easy-to-follow examples.


Now it's time to dance


Copyright (C) 2012 EdgeCase

Distributed under the Eclipse Public License, the same as Clojure.


Version 0.4.0

  • Remove support for searching for filenames, because it has very sharp edges
  • Throw a FileNotFoundException instead of failing silently when files in a manifest aren't found
  • Directory contents are listed in alphabetical order (avoids intermittent failures due to file directory order on Linux)
  • Rewritten internals, with more reliable and consistent string and filename handling
  • Referring to assets using different extensions is no longer supported

Version 0.3.0

  • Use v8 for Less, Hamlcoffee and CoffeeScript
  • Cache and avoid recompiling CoffeeScript and HamlCoffee files which haven't changed
  • Update to lein2
  • Improve stack traces upon failure in Rhino
  • Update Coffeescript (1.3.3), Less (1.3.0) and Hamlcoffee (1.2.0) versions
  • Ignore transient files from vim and emacs
  • Better error reporting of HamlCoffee
  • Support multiple asset directories
  • Add expire-never headers
  • Improve Rhino speed by using one engine per thread
  • Update to latest Rhino for better performance
  • Support for lein dieter-precompile
  • Add mime type headers for dieter files

Version 0.2.0

  • Handlebars templates are now a separate library. dieter-ember
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