CSS/JScript Aggregation, caching and performance – customizations do not show up

Drupal employs a great mechanism for speeding up page loads once active development has been completed. Under the Performance settings, there are several options for caching pages, CSS and more. As an example, from a high level, CSS files are consolidated from the often several dozen files down to one, with all whitespace, redundant or superseded selectors and comments removed. This is a great way to speed up your site once you are in Production. If you’re actively developing your site, you don’t want to use this because your changes won’t show reliably without constantly clearing your cache.

There are some caveats though. What? Caveats in Drupal? Uh, yeah. I love Drupal but it has more caveats than the US congress has vacations.

The symptoms are always the same – custom changes (to CSS, for example) don’t show up. In my case, Adaptive Themes manifests this type of behavior. AT has a way of “pre-caching” info within its area of Drupal and this will often lead to CSS customizations  not showing up once performance caching has been enabled.

In AT’s case, there is a work around. If changes don’t appear:

  1. Clear the cache
  2. Immediately save the AT Theme/Subtheme you are using under Appearance
  3. Clear the cache again

That should do it. You can read the conversation between some of the AT geniuses here:


It’s pretty recent and they will have a solution at some point soon, I hope. Considering how awesome AT is, with all of the Responsive features and easy subtheming, this is a pretty small accommodation to make.

Responsive Design and Drupal

I’m working with the responsive design side of Drupal now to prepare my site for mobile devices. Drupal utilizes responsive design at the theme level. This is the reason that I chose Adaptive Themes (AT) Core – it’s responsive out of the box. But there are still many considerations for approaching mobile devices.

This post will be a collection of links that I find useful for responsive design in the context of Drupal generally and AT specifically, starting with the wonderful readme by Jeff Burnz.

http://zomigi.com/blog/essential-considerations-for-crafting-quality-media-queries/#mq-overlap-stack – great blog on media queries and stacked v overlapping.

http://getlevelten.com/blog/tom-nelson/three-ways-use-media-queries-drupal – Excellenrt blog specifically about Media Queries and Drupal.

http://www.youtube.com/watch?v=XyIOj7fUZ7w – great vid from Lynda.

this is the readme from jeff burnz. I can’t attach .txt – WP doesn’t like that so here is the full text.

First read this about SASS, its very important!

There is more information regarding working with SASS in the SASS CSS folder
_README, however, you need to be aware that if you set Compass to watch the
SASS folder or any SCSS file in this theme it will OVERWRITE the CSS file/s in
your sub-themes CSS directory!

To prevent this ever happening you can delete the config.rb file in the
sub-theme root (unless you are actually planning on using SASS, in which case
you will want to keep it).
Working with Responsive Design in Adaptivetheme

The subtheme is designed to be “mobile first”. In short this means to
first load a set of global styles, the progressively add styles for larger
devices using media queries.

Its important to note that you do not have to follow a mobile first approach.
Adaptivetheme can support Desktop first approach as well, which means you will
progressively add styles to override things for mobile, rather than progressively
adding style for larger devices.

You can do both in Adaptivetheme – it’s merely a matter of where you place
the majority of your styles, and what theme settings you choose in the
Appearance settings for your sub-theme.

Lets examine the CSS file structure of Adaptivetheme and look at how each
file is loaded. From this you will be able to deduce what approach might work
for you, and where you should be placing your CSS.
Moible First or Desktop First – that is the Question!

Depending on your approach AT will load the stylesheets in a different order,
indeed it will load different stylesheets. You MUST make a conscious decision
which to use and set this in theme settings.

Look under CSS settings. By default AT is set to Mobile first, if you want to do
Desktop first you should change this setting.
Global Styles

The global styles do not target any specific device – they always load for all

There are two main global stylesheets:

– global.base.css
– global.styles.css

global.base.css – this holds a few imoportant declarations that should probably
not be removed, however you can modify them, such as gutter width and flexibile
image/media styles.

global.styles.css – includes a slighly modified normalize reset and many empty
selectors for elements and drupal classes and id’s. If you prefer you can delete
everything in global.styles.css and start with a clean slate.

The selectors are extensive and you should delete unused selectors before
going live to reduce CSS weight. You can use cleancss.com or a better way is
just use SASS, it does this for you.

Each file includes a lot of comments and documentation, please review each of
the global CSS files for more help.

If you are doing mobile first then you will probably keep things to a minimum
in these files. “Minimum” is relative, this might still be a lot of CSS,
never-the-less its worth keeping in mind the mobile view of the site, and
avoid writing CSS rules that are clearly for larger width devices.
Responsive Styles

Adaptivetheme 7.x-3.x has two “modes” – Development mode and Production mode.
Depending on what mode you are in the stylesheets will load differently.

Mode changes automatically depending on CSS aggregation settings. When CSS
aggregation is ON, the its in Production mode.

If you don’t know what CSS aggregation is, look here:

## Responsive Styles – Development mode

In Development mode (CSS aggregation OFF) the responsive stylesheets will load
in individual link elements with the media query in media attribute.

This allows them to load directly into the browser and you will see your CSS
changes immediately, as per normal CSS development.

There are five of these responsive stylesheets – one for each break point set
in the theme settings:

– responsive.smartphone.landscape.css
– responsive.smartphone.portrait.css
– responsive.tablet.landscape.css
– responsive.tablet.portrait.css
– responsive.desktop.css

Its important to know that these files DO NOT contain the media queries,
instead they load in the <link> elements media attribute – remember, these
files only load when in Development Mode.
## Responsive Styles – Production mode

When in production mode all the responsive stylesheets are aggregated into one
file and use embedded @media queries. AT Core will automatically aggregate
the CSS from each of the development mode stylesheets and wrap it in the right
media query. This reduces the number of HTTP requests from 5 to 1.

This file is always called:

– ThemeName.responsive.styles.css

You will find this file at:

~/[public files]/adaptivetheme/[ThemeName]/ThemeName.responsive.styles.css

NOTE: please see the section below titled “Relative Paths in Responsive Styles”.
## Important Note about CSS Aggregation and Responsive Stylesheets

Once you have CSS aggregation ON if you make changes to any responsive
stylesheet, you MUST re-save the theme settings AND clear the sites cache. AT
Core will re-write the saved files, then clearing the cache tells Drupal to
use the new file.
## Relative Paths in Responsive Stylesheets

When CSS aggregation is ON AT Core will load the production version of your
responsive styles (see above “Production mode”). this file is loading from
Public Files and not from within your theme so special handling is required for
relative assets – AT Core will do this for you.

AT Core will automatically re-write the relative paths to the files so they
are relative to the site root. This is the same functionality as Drupal core
CSS aggregation feature, so paths are not broken.

If you use absolute paths these will not be altered.
Overlapping/Custom Media queries

By default the media queries in Adaptivetheme are “stacked”, meaning they do
not overlap. This makes it very easy to target one set of device width and not
have those styles “leak” over into others. However it can also mean you may
need to duplicate CSS that you would rather have cascade.

To use custom media queries the sub-theme includes a special file called:


To enable the use of this file in your theme see your theme settings:

Layout & General Settings > CSS > Custom Media Queries

This file has embedded media queries which means you MUST set them yourself.
Defaults are provided.

Allowing styles to cascade can result in a huge saving on total CSS weight and
speed up development.
Internet Explorer Styles and Scripts

AT can load conditional stylsheets and scripts from you sub-themes info file.

Please see adaptivetheme_subtheme.info – there are good docs and examples of
how to declare stylesheets and scripts for Internet Explorer.

Adaptivetheme also includes special conditional classes on the HTML element
which allow you to easily target styles at specific version of IE.

These are the classes you can use:

.iem7 (IE7 Mobile)
.lt-ie7 (less than IE7)
.lt-ie8 (less than IE8)
.lt-ie9 (less than IE9)

Use these if you only have a small number of overrides and do not want to load
a dedicated conditional stylesheet.

Ping me on Skype if you have life/death critical issues to report…

Skype: jmburnz

Otherwise support my work by joining my theme club, it really does fund my
contrib projects:


Or, you could get radical and file a support issue, even post a patch (which
makes me very happy):


Customizing my Drupal theme – Adaptive Themes Core

well, it is time that i started customizing my theme. i knew that i would want to do this myself so i put some thought into my theme choice before I started. and I decided to with adaptive themes core.

AT Core 7.x-3.1

AT Core is the framework that drives the responsive layout system and provides an extensive set of tools for theme development. You do not need to enable this theme. Use the provided AT Subtheme to get started.
this theme is pretty basic to begin with. and while it isn’t hard at all to create your own subtheme (and you should do it just to get a good understanding of drupal theme architecture) it is nice that AT comes with one ready to be destroyed. note – if you plan on modifying a theme, make a subtheme out of it first. that way it can still take advantage of upgrades via drupal.org. I also chose it because it is a responsive theme, meaning that it does media queries to determine screen width. This is important for mobile devices and tablets. AT also has good documentation and support. I’ll post links to this post as I find them.
AT on Drupal.org – the main page
AT Documentation – Very good stuff here, and professional service options too.
I have my sandbox in pretty good shape. and it is using the same theme and subtheme. So, I will be doing my development there and then transferring the files to prod. Make sure that you disable any caching that you might have enabled so that you get fresh versions of changes as they are made.

Panels – Adaptive Themes vs Panoply

For me (and I believe for anyone) having a responsive theme is absolutely critical. Mobile is here, huge and can be ignored at your traffic’s peril. Make sure your theme uses media queries for browser width, which means adapts for mobile. Here are some good links about testing on mobile.

Mobile phone emulator (by COWEMO)

10 Excellent Tools for Testing Your Site on Mobile Devices

Also, I want to use Panels and Panels Everywhere. For the site that I am working on now, I need the power of Panels to get what I want now. My own goal is to continue studying PHP and eventually make contributions to Drupal at the code level. And to be able to design sites purely through PHP. But that is a ways off right now and I need to get this site up and running before that time. So, although I feel like Omega has so much to offer in Responsiveness, I am going with AT because they have good integration thematically with Panels and the Responsive paradigm.

Then there is Panoply, which is an actual distribution that has many things to offer and is worth taking a look at. This is a link to a good article by Drupal guru Jeff Burnz, which although biased (he’s Mr AT) brings up good points about Distros and maintenance. Read this article.


So, I’m going with AT for the current project.