Grymt - because I didn't invent Grunt here

18 April 2014   3 comments   Python, Web development, Javascript

Mind That Age!

This blog post is 4 years old! Most likely, its content is outdated. Especially if it's technical.

grymt is a python tool that takes a directory full of .html, .css and .js and prepares the html for optimial production use.

For a teaser:

  1. Look at the "input"

  2. Look at the "output" (Note! You have to right-click and view source)

So why did I write my own tool and not use Grunt?!

Glad you asked! The reason is simple: I couldn't get Grunt to work.

Grunt is a framework. It's a place where you say which "recipes" to execute and how. It's effectively a common config framework. Like make.
However, I tried to set up a bunch of recipes in my Gruntfile.js and most of them worked well individually but it was a hellish nightmare to get it all to work together just the way I want it.

For example, the grunt-contrib-uglify is fine for doing the minification but it doesn't work with concatenation and it doesn't deal with taking one input file and outputting to a different file.
Basically, I spent two evenings getting things to work but I could never get exactly what I wanted. So I wrote my own and because I'm quite familiar with this kind of stuff, I did it in Python. Not because it's better than Node but just because I had it near by and was able to quicker build something.

So what sweet features do you get out of grymt?

  1. You can easily make an output file have a hash in the filename. E.g. vendor-$hash.min.js becomes vendor-64f7425.min.js and thus the filename is always unique but doesn't change in between deployments unless you change the files.

  2. It automatically notices which files already have been minified. E.g. no need to minify somelib.min.js but do minify otherlib.js.

  3. You can put $git_revision anywhere in your HTML and this gets expanded automatically. For example, view the source of and look at the first 20 lines.

  4. Images inside CSS get rewritten to have unique names (based on files' modified time) so they can be far-future cached aggresively too.

  5. You never have to write down any lists of file names in soome Gruntfile.js equivalent file

  6. It copies ALL files from a source directory. This is important in case you have something like this inside your javascript code: $('<img>').attr('src', 'picture.jpg') for example.

  7. You can chose to inline all the minified and concatenated CSS or javascript. Inlining CSS is neat for single page apps where you have a majority of primed cache hits. Instead of one .html and one .css you get just one .html and the amount of bytes is the same. Not having to do another HTTP request can save a lot of time on web performance.

  8. The generated (aka. "dist" directory) contains everything you need. It does not refer back to the source directory in any way. This means you can set up your apache/nginx to point directly at the root of your "dist" directory.

So what's the catch?

  1. It's not Grunt. It's not a framework. It does only what it does and if you want it to do more you have to work on grymt itself.

  2. The files you want to analyze, process and output all have to be in a sub directory.
    Look at how I've laid out the files here in this project for example. ALL files that you need is all in one sub-directory called app. So, to run grymt I simply run: grymt app.

  3. The HTML files you throw into it have to be plain HTML files. No templates for server-side code.

How do you use it?

pip install grymt

Then you need a directory it can process, e.g ./client/ (assumed to contain a .html file(s)).

grymt ./client

For more options, check out

grymt --help

What's in the future of grymt?

If people like it and want to add features, I'm more than happy to accept pull requests. Some future potential feature work:


Peter Müller
If you find Grunt cumbersome to set up, you might want to have a look at assetgraph-builder. The working mantra is that if your browser can understand your page, so should your build system. So you shouldn't need any build system specific annotations in the code, a manifest or configuration file in order to build the page. Sounds like the things you have set up are covering some of the same areas we've already covered pretty well.
Peter Bengtsson
assetgraph-builder looks like it does a millions things. Does it work with angularjs templates?
Peter Müller
It certainly does a lot of things. It's a quite opinionated best practice implementation that does every optimization we could think of. Creating alternate versions that do less isn't that difficult. Most of the build system deals with formatting input arguments correctly, the real magic happens on about 100 lines in lib/transforms/buildProduction, meaning it's quite easy to write an alternate version that does less.

There is angularjs template support, provided you follow the syntax they specify in their documentation.

Your email will never ever be published

Related posts

COPYFILE_DISABLE and python distutils in python 2.6 12 April 2014
Wattvision - real-time energy monitoring 27 April 2014
Related by Keyword:
csso and django-pipeline 28 February 2018
gulp-header is the best! 09 April 2015
Comparing Google Closure with UglifyJS 10 July 2011
Comparing jsmin and slimmer 17 September 2009
Related by Text:
Be very careful with your add_header in Nginx! You might make your site insecure 11 February 2018
jQuery and Highslide JS 08 January 2008
I'm back! has been renewed 05 June 2005
Anti-McCain propaganda videos 12 August 2008
I'm Prolog 01 May 2007