Is there a way to redefine SASS mixins. I want to override SASS mixins for site specific styling needs. Is there a way to do it ?
My quick bit of testing seems to show that you can override mixins without a second thought. You can't reopen them to the extent that would allow you to override only certain attributes, but you can easily replace them entirely.
sample.sass:
=test
color: red
font-weight: bold
=test
color: blue
p
+test
sample.css:
p {
color: blue; }
Note that this test was performed using Haml/Sass 3.0.2 (Classy Cassidy), so this may not hold true for earlier versions, if you were getting an error before.
Related
I have a background image:
app/assets/images/bg.jpg
It works ok in development with the stylesheet as:
body {
background: #111 url('bg.jpg') repeat-x;
color: #DDD;
font: normal 90% "Trebuchet MS",Verdana,sans-serif;
margin-left: 1.2em;
}
But in production it doesn't show and the logs show:
ActionController::RoutingError (No route matches [GET] "/assets/bg.jpg"):
When I am using html and js templates I can add .erb to add the rails pre-processing that will let me use things like paths and helpers, e.g. images_url
How can I either:
a) Do a similar thing with my stylesheet
b) Use a path that works in both dev and prod. I tried [nothing] and images/ and they didn't work.
In the newer versions of rails, when you have a .css.scss stylesheets you have available a couple of helpers that will help you achieve that (you don't have to use .erb at all) like image-path and image-url (please take a look at the helpers section here https://github.com/rails/sass-rails)
basically what you need to do to get it working is replace
background: #111 url('bg.jpg') repeat-x;
for this
background: #111 image-url('bg.jpg') repeat-x;
and thats it. (also add the scss extension if you haven't already)
Precompile
You'll want to make use of the asset_path_helpers, specifically asset_url with one of the Rails asset preprocessors (SCSS / SASS)
The problem you'll have in production is that Rails appends what's known as a "fingerprint" to the assets. This fingerprint serves to define the uniqueness of the precompiled files:
Fingerprinting is a technique that makes the name of a file dependent
on the contents of the file. When the file contents change, the
filename is also changed. For content that is static or infrequently
changed, this provides an easy way to tell whether two versions of a
file are identical, even across different servers or deployment dates.
This means that when you push to production (and by virtue, precompile) the assets, you'll end up with the "bg.png" in a totally different location than that which you're referencing in the standard file.
--
Helpers
The trick is to use a dynamic path helper with the preprocessors:
#app/assets/stylesheets/application.css.scss
body {
background: #111 asset-url('bg.jpg') repeat-x;
color: #DDD;
font: normal 90% "Trebuchet MS",Verdana,sans-serif;
margin-left: 1.2em;
}
This should work for you
The fix that worked for me was to have
background: #111 url('<%= image_path "bg.jpg" %>') repeat-x;
and name my file .erb as in default.scss.css.erb
The other approaches didn't work.
Background
I want to enable right-to-left locales as well as left-to-right, but I only want to maintain a single set of stylesheets.
The idea is that calling application-rtl.css will serve a rtl-converted version of application.css (using r2).
This functionality has two use-cases:
development: serve dynamically, converting on the fly
production: have precompilation generate the -rtl versions (extending rake assets:precompile task)
So far, I've managed to implement a RTLConverter that enables me to serve all my stylesheets converted to RTL without having touched them at all:
config/initializers/rtl_converter.rb:
require "r2"
require "tilt"
class RTLConverter < Tilt::Template
def prepare; end
def evaluate(context, locals, &block)
R2.r2 #data
end
end
Rails.application.assets.register_preprocessor 'text/css', RTLConverter
You can also implement this as an engine for sprockets to only convert files having the .rtl extension:
Rails.application.assets.register_engine 'rtl', RTLConverter
My question
How can I hook into the asset pipeline in order to:
serving an on-the-fly converted version of any stylesheet with the name-postfix '-rtl' (look for the file without the postfix and serve a converted version of that)?
creating converted copies with the name-postfix '-rtl' of all stylesheets during precompilation
Notes:
The converter does not work in conjunction with the sass engine, but seems to work fine with less. It's been applied to a twitter-bootstrap based site and works like a charm.
The converter has not been tested in production.
If I can find a decent solution to this problem, I intend to create and maintain a gem and give it back to the community.
I would aim for just using CSS directly to handle the LTR-RTL differences. CSS can probably handle the job for you. In case you define your CSS as LTR, then, based on a CSS class you can override the stuff you want.
Per default, define your entire CSS stylesheet as LTR.
Put an extra css class on the body which handle the locale. For instance <body class="RTL">
Define all exceptions to the default by overriding with CSS classes prefixed by "RTL"
A short example. Original "default" styles:
body { direction: ltr; }
.sidebar { width: 200px; float: right; margin-left: 30px }
Then, overwrite relevant styles later in your css:
body.rtl { direction: rtl; }
.rtl .sidebar { float: right; margin-right: 30px; }
/*remember to 'reset' all defaults for example: */
.rtl .sidebar { margin-left: 0; }
With sass, you have a common place to define standard variables, for instance margin in the example above. Your mileage may vary. But to me, that sounds more simple than messing with asset pipeline.
Unfortunately, none of the other answers really suggested the solution I was looking for, so after digging into matters, I was able to come up with a simple gem that could flip the stylesheet based on the filename.
So by including that gem and serving up a version of the stylesheet with '-flipped' appended to the name, I am now able to serve an automatically flipped version both in dev and production.
Find the gem on rubygems.org: stylesheet_flipper
Find a usage description on gihub: monibuds/stylesheet_flipper
As far as I can tell, Sprockets does not expose any hooks into the path lookup mechanism to processors. Even if it did, I don't think you could invoke some generalized "read asset" method.
All in all, I fear that making AP do what you want would require some serious arm-twisting.
So here's a completely different idea. What if you:
Dropped on-the-fly asset processing altogether, even in development
Had a Guard task set up to
recompile assets when their sources change (I think this exists already)
generate the RTL versions of the compiled CSS
Push the compiled assets to production (gasp!)
In other words, maybe you could trade some of the AP features for increased flexibility?
(I'm not going for the bounty here because this is just an idea, not a solution)
Wrote about this issue a year ago:
http://amitkazmirsky.com/2011/05/29/dry-your-rtl-and-ltr-css-files-in-rails-with-sass/
Basically my approach was to write the css with direction as variables:
#user-box {
backgroud-color: white;
padding: 0 5px;
float: $dir;
}
#side-nav {
margin-#{$opdir}: 5px;
}
I am developing an embeddable widget that needs to have all its CSS properties declared as important to prevent CSS bleed of the embedding page. This means that if I want to use some pre-existing CSS framework (like Bootstrap), or some jQuery plugin that uses a CSS stylesheet, I have to manually copy-paste the CSS in my assets folder and add !important declarations to each property. This seems a rather unmaintainable and error prone process.
As per title, is there a way to extend the SASS preprocessor to add !important to any declared property for an imported file or partial?
No,
Sass doesn't have that functionality, because it is the most uncommon thing you would want to do in Sass, or CSS, or anywhere for that matter.
However, from what I understand, you want to add in the !important to all the CSS properties in a particular file. In that case, you can just simply do a Search & Replace:
Search for ; and replace with !important;
The most obvious solution is to create a new mixin, potentially with the word important appended like so:
%margin-none-important {
margin: 0 !important;
}
And then in your code:
.no-margin {
#extend %margin-none-important;
}
So I have an rails admin system that will allow a user to choose a theme, basically a set of SASS color variables that will recompile application.css.scss with the new colors. How would be the best way of going about changing this when the user selects from a drop down and submits? I read some up on some problems with caching and recompiling but I'm not totally clear how to set it up.
Currently I have..
application.css.scss
#import "themes/whatever_theme";
#import "common";
#import "reset";
#import "base";
themes/_whatever_theme
$theme_sprite_path: '/images/sprite_theme_name.png';
$main_color:#009DDD;
$secondary_color:#b3d929;
$light_background:#f2f2f2;
$border_line:#e6e6e6;
$off_white:#f9f9f9;
$white:#ffffff;
$font_body:#565b59;
$font_headers:#363a36;
Say I have 5 different themes the user will switch between, it would be nice to set variable names for each theme in Rails then pass these down to SASS and change them on the fly and recompile. Is this the best way to go about this?
3 easy steps:
Compile all themes into different files upon deploy. This will take care of timestamping, zipping, etc.
Render page with default theme.
Use javascript to load alternate theme CSS.
No need to mess with dynamic compilation and all that.
To load a CSS dynamically you can use something like this:
function loadCSS(url) {
var cssfile = document.createElement("link");
cssfile.setAttribute("rel", "stylesheet");
cssfile.setAttribute("type", "text/css");
cssfile.setAttribute("href", url);
}
Sergio's answer is valid, but omits the sassy details and I'd used a slightly different approach.
You're using SASS in Rails- don't fight the current, be Railsy and let the asset pipeline precompile all your CSS. Unless you're trying to do something extreme like CSSZenGarden with hundreds of themes, or each theme is thousands of lines I'd recommend setting each theme as it's own CSS class rather than it's own file.
1kb of extra CSS in the rendered application.css file won't bog down your users
It's straightforward to switch theme classes with JQuery: $(".ThemedElement").removeClass([all your themes]).addClass("MyLittlePonyTheme");
As implied, you will have to tag the elements you want the update with the ThemedElement class
You could alternatively just change the class on your top level element and make liberal use of inheritance and the !important declaration, although I find the other approach more maintainable.
If you think you can manage your themes with classes rather than files, here's how we generate them with SASS. SASS doesn't support json style objects, so we have to reach way back and set up a bunch of parallel arrays with the theme properties. Then we iterate over each theme, substitute the dynamic properties into the auto generated theme class, and you're off to the races:
themes.css.scss
#import "global.css.scss";
/* iterate over each theme and create a CSS class with the theme's properties */
#for $i from 1 through 4{
/* here are the names and dynamic properties for each theme class */
$name: nth(("DefaultTheme",
"MyLittlePonyTheme",
"BaconTheme",
"MySpaceTheme"
), $i);
$image: nth(("/assets/themes/bg_1.png",
"/assets/themes/bg_2.png",
"/assets/themes/bg_3.png",
"/assets/themes/bg_4.png"
), $i);
$primary: nth((#7ca8cb,
#3c6911,
#d25d3a,
#c20d2c
), $i);
$font: nth((Rosario,
Helvetica,
Comic Sans,
WingDings
), $i);
/* Now we write our Theme CSS and substitute our properties when desired */
.#{$name}{
&.Picker{
background-image:url($image);
}
color: $primary;
.BigInput, h1{
color: $primary;
font-family: $font, sans-serif !important;
}
.Frame{
background-image:url($image);
}
.Blank:hover{
background-color:mix('#FFF', $primary, 90%) !important;
}
.BigButton{
background-color:$primary;
#include box-shadow(0,0,10px, $primary);
}
/* and so on... */
}
It's a bit of a hack, but it's served us really well. If your themes are uber complicated or you have too many of them it gets more painful to maintain.
One option is to simply load a set of custom css rules (your theme) after your application.css and let your theme override the default colors from application.css. You could just add a database column "theme" and load the css with this name dynamically like.
SASS is not designed for compiling dynamic data on the fly. If you want dynamic css processing, you could add a controller method called "custom_css" and make this respond to the css format and load this dynamically with inline variables, but I don't think SASS is meant to be used for it at all.
I believe that you could use erb to inline variables in sass. I'm not positive, but I think it would look something like this:
themes/_whatever_theme.sass.erb
$theme_sprite_path: '<%= Theme.sprite_path %>';
$main_color: <%= Theme.main_color %>;
$secondary_color: <%= Theme.secondary_color %>;
These should be created dynamically for each page load. I'm not sure how the caching would work here.
I read about many CSS related languages and tools which need ruby.
What is the purpose of these
languages and tool how these can save
time and improve our CSS coding.
What is the role in ruby language in
these languages and tool.
Will i have to install and learn
ruby language to use these languages and tool.
will i need ruby installed on
webserver where website will be
hosted.
I'm talking abut these languages
http://lesscss.org/
http://sass-lang.com/
http://compass-style.org/
some mentioned here:
http://www.ruby-toolbox.com/categories/css_frameworks.html
I'm on Windows XP PC , How can i use these Ruby based languages and which is preferred? I don't know ruby language.
the point
the point of these languages (i prefer, however frameworks or extensions) of css is to incorporate your workflow to your css saving you time. How?
Let's imagine, that you have div with class some-long-class-to-be-sure-what-it-does and that div has h3 child, p child, .some-other-class child and something else (span child).
Now, if you want to style all of them, you have to do something like this:
.some-long-class-to-be-sure-what-it-does { width: 120px; }
.some-long-class-to-be-sure-what-it-does h3 { font-size: 20px; }
.some-long-class-to-be-sure-what-it-does p { margin-bottom: 30px; }
.some-long-class-to-be-sure-what-it-does .some-other-class { width: 120px; }
to inform browser about (i.e.) only h3 of .some-long-class-to-be-sure-what-it-does has font-size: 20px;.
with most of these parsers/frameworks, you have (still just an example) nesting at hand:
.some-long-class-to-be-sure-what-it-does {
width: 120px;
# h3 { font-size: 20px; }
# p {
margin-bottom: 30px;
# .subclass { color: red; }
}
# .some-other-class { width: 120px; }
}
which gives you smaller css, easier to edit in a long run (this is subjective, you may find it's harder for you to work with).
Also, they extend css in other ways besides nesting: constants (assign something to #col1 and use it on three places, then you decide, that you need something lighter... bam! you edit it once), flags, output formatting and many more, so I guess you will find your way of using it.
how to us it
mostly, you don't install it on your PC, but rather on your server. Instead of classic CSS, you link your site with installed CSS parser/framework/language, which on every call calculates (or will use cached version if avalaible) normal css - but when you edit it, you edit simplified/extended version of your css.
Edit: you don't install it onto your PC as a USER, but you need to install it into your developing enviroment. If it's localhost on your PC, then yes, you install it in your PC - but not as a user, but on your locally running server.
Ruby?
I think, that for ruby, these extensions to css were first. But now you can find it for other languages aswell - I, as PHP programmer, have found Anthony Short's CSScaffold:
github with little description
http://github.com/anthonyshort/csscaffold
scaffold's website, currently offline
http://scaffoldframework.com/
edit: what's it's use?
In that try example you see counting with multiple constant. that way, if you change !sidebar from 200px to 300px, every part of your css recalculates with it. every place this constant is mentioned, wheter by itself or in calculation.
another:
SASS in .NET - Better CSS in .NET?
less css in .NET - http://www.dotlesscss.com/
You don't need anything on your PC, these should be installed on your webserver and you have to write css code according to frameworks' rules.
Once you do that when you deploy your webapp to server these frameworks compile your styles and convert them to traditional stylesheets.
As far as i know this is mostly what they do.
Sinan.