JS and CSS automated merge and minifier. Optionally can render django template tags to static css and js files.
Latest commit 29300be Apr 24, 2014 @xgvargas Update README.md



This is a python script for automated merge and minify of JS and CSS files.

Optionally it can parse django template tags embeded into css and js files.

And, if you have lesscpy installed, you can compiled .LESS to .CSS before merging.


$pip install jscssmin --target $PYTHONPATH --install-option="--install-scripts=~/bin"

Be sure to point scripts to a place here you have write access and is in your path.

Example with a django project

During development I simply use django tags like {% url ... %} and {% static ... %} on my .js and .css files to define dynamic url to views and images of my project. At this point the .js and .css are placed into the templates directory of my app so I can {% include ... %} it to my .html templates and have the tags rendered to final urls. Of course the js and css will appear inline with the HTML content. For development I think this is fine.

On deploy you usually want all your javascript and styling to be in a single external file.

Here is how this script can help you with that:

On my base.html template I usually have something like this:

<!-- css -->
{% if debug %}
  <link href="{% static 'tasks/css/fixtypeahead.css' %}" rel="stylesheet">
  <link rel="stylesheet/less" type="text/css" href="{% static 'message/css/message.less' %}" />
  <link rel="stylesheet/less" type="text/css" href="{% static 'tasks/css/tasks.less' %}" />
  <link rel="stylesheet/less" type="text/css" href="{% static 'tasks/css/compactform.less' %}" />
{% else %}
  <link href="{% static 'tasks/css/compactform.css' %}" rel="stylesheet">
  <link href="{% static 'css/mydeploycss.min.css' %}" rel="stylesheet">
{% endif %}
{% block extracss %}{% endblock %}

<!-- js -->
{% if debug %}
  <!-- you need this only while debugging with less files -->
  <script type="text/javascript" src="{% static 'js/less-1.6.2.min.js' %}"></script>
  <script src="{% static 'js/code1.js' %}"></script>
  <script src="{% static 'js/code2.js' %}"></script>
    // js bellow contains django tags inside
    {% include 'tasks/code3template.js' %}
    {% include 'tasks/codentemplate.js' %}
    {% include 'message/moretemplatecode.js' %}
{% else %}
  <script src="{% static 'js/deploycode.min.js' %}"></script>
{% endif %}
{% block extrajs %}{% endblock %}

Check out less.js for a less compiler at client side.

Create a file named jscssmin.yaml next to your manage.py (if using django, otherwise put this file in your root). Here's a example:

config: myapp.settings
    - /home/username/apps_wsgi/myapp
    #more paths as you need
    my js:
            - static/js/code1.js
            - static/js/code2.js
            - tasks/templates/tasks/code3template.js
            - tasks/templates/tasks/codentemplate.js
            - message/templates/message/moretemplatecode.js
        #all static and rendered template JS will be merged, minified and saved to:
        jsmin: static/js/deploycode.min.js
    my css:
            - tasks/static/tasks/css/fixtypeahead.css
            - message/static/message/css/message.less
            - tasks/static/tasks/css/tasks.less
        #the static css and the css compiled from less files are merged, minified and saved to:
        cssmin: static/css/mydeploycss.min.css
            - tasks/static/tasks/css/compactform.less
        #the single less is compiled to css and saved as is to:
        full: tasks/static/tasks/css/compactform.css

Here we define a path to the django project and the settings.py file to use while rendering the template tags. You only need to define those if you have tags inside .js or .css, if you don't then simply ignore both.

In this case we have three blocks, my js, my css and compact.

For the first block all five javascript files are going to be merged, minified and saved to a single deploycode.min.js file. (Yes, the 3 files under template will be rendered before merge)

For the second block we have one .css and two .less files merged and minified.

In our least block the compactform.less file is compiled to CSS and saved as is to a CSS file.

Is up to you not to mix JS and CSS/LESS inside a single block.

Once you update/checkout the work copy of your django project on your server all you have to do is:

Processing block: compact
Compiling LESS: tasks/static/tasks/css/compactform.less
Saving: tasks/static/tasks/css/compactform.css (0.17kB)

Processing block: my css
Merging: tasks/static/tasks/css/fixtypeahead.css
Compiling LESS: message/static/message/css/message.less
Compiling LESS: tasks/static/tasks/css/tasks.less
Full merged size: 2.66kB
Minifying CSS...  Final: 72.7%
Saving: static/css/mydeploycss.min.css (1.93kB)

Processing block: my js
Merging: static/js/code1.js
Merging: static/js/code2.js
Merging template: tasks/templates/tasks/code3template.js
Merging template: tasks/templates/tasks/codentemplate.js
Merging template: message/templates/message/moretemplatecode.js
Full merged size: 34.66kB
Minifying JS...  Final: 50.1%
Saving: static/js/deploycode.min.js (17.35kB)

$python manage.py collectstatic
$touch /path/to/yourwsgi.wsgi

Ok, this least step can change on your server, but that's the overall idea...

Also, you can use the option --images to optimise all .PNG and .JPG present on the directory tree starting where you executed this script (usualy your django project root). Like:

$python jscssmin.py --images

This will save a copy of all original images with ".original" appended to its name and a smaller (hopefully), version will be saved with the original name. This script will ignore every file that already have a .original version present. To force this script to process every single file again use the option --images-full.

Non django project

No secret: simply create a jscssmin.yaml file here there is no definition of config, and define all static files you want to merge/minify. Without a defined config all files under templates are going to be ignorated.

Using as a minifier module

In another python script:

import  jscssmin

#minify JS from text to file
fulljstext = '<script>full code....</script>'
jscssmin.jsMin(fulljstext, 'path/to/min/code.js')

#minify CSS from text to file
fullcsstext = '<style>full styles...</style>'
jscssmin.cssMin(fullcsstext, 'path/to/min/style.css')

#minify a JPG image

#minify a PNG image

All four functions used above are only helpers to call some online minifer api. See below. This script does not minify JS or CSS by itself, so you need to be online to execute it with success.


This script uses some great online api provided by @andychilton for all minify action: