I have been looking at tailwind CSS, when I am using it, it feels like writing style inside HTML. Which makes this an awkward library to use for me. But while I was looking at it I got an idea.
Instead of using tailwind like this
<div class="p-4 flex text-lg">Something</div>
Is it possible for me to do this using some CSS preprocessor:
// in html
<div class="some">Something</div>
// in css (with a preprocessor)
.some {
include: .p-4;
include: .flex;
include: .text-lg;
}
This way I don't have to write style in HTML but still get the benefits of tailwind's utility classes.
I know Scss has mixins, but as far as I know tailwind only provides classes and not mixins, and I have no experience with any other CSS preprocessor. So is there any preprocessor that supports this feature?
With SCSS, #extend could do the job. However, it will only work if you have access to the classes you want to extend. As for Tailwind CSS, I think #apply is the built-in way to do what you want.
I know CSS very well, but am confused about Sass. How is SCSS different from CSS, and if I use SCSS instead of CSS will it work the same?
In addition to Idriss answer:
CSS
In CSS we write code as depicted bellow, in full length.
body{
width: 800px;
color: #ffffff;
}
body content{
width:750px;
background:#ffffff;
}
SCSS
In SCSS we can shorten this code using a #mixin so we don’t have to write color and width properties again and again. We can define this through a function, similarly to PHP or other languages.
$color: #ffffff;
$width: 800px;
#mixin body{
width: $width;
color: $color;
content{
width: $width;
background:$color;
}
}
SASS
In SASS however, the whole structure is visually quicker and cleaner than SCSS.
It is sensitive to white space when you are using copy and paste,
It seems that it doesn't support inline CSS currently.
$color: #ffffff
$width: 800px
$stack: Helvetica, sans-serif
body
width: $width
color: $color
font: 100% $stack
content
width: $width
background:$color
CSS is the styling language that any browser understands to style webpages.
SCSS is a special type of file for SASS, a program written in Ruby that assembles CSS style sheets for a browser, and for information, SASS adds lots of additional functionality to CSS like variables, nesting and more which can make writing CSS easier and faster.
SCSS files are processed by the server running a web app to output a traditional CSS that your browser can understand.
css has variables as well. You can use them like this:
--primaryColor: #ffffff;
--width: 800px;
body {
width: var(--width);
color: var(--primaryColor);
}
.content{
width: var(--width);
background: var(--primaryColor);
}
Variable definitions right:
$ => SCSS, SASS
-- => CSS
# => LESS
All answers is good but question a little different than answers
"about Sass. How is SCSS different from CSS" : scss is well formed CSS3 syntax. uses sass preprocessor to create that.
and if I use SCSS instead of CSS will it work the same? yes. if your ide supports sass preprocessor. than it will work same.
Sass has two syntaxes. The most commonly used syntax is known as “SCSS” (for “Sassy CSS”), and is a superset of CSS3’s syntax. This means that every valid CSS3 stylesheet is valid SCSS as well. SCSS files use the extension .scss.
The second, older syntax is known as the indented syntax (or just “.sass”). Inspired by Haml’s terseness, it’s intended for people who prefer conciseness over similarity to CSS. Instead of brackets and semicolons, it uses the indentation of lines to specify blocks. Files in the indented syntax use the extension .sass.
Furher Information About:
What Is A CSS Preprocessor?
CSS in itself is devoid of complex logic and functionality which is required to write reusable and organized code. As a result, a developer is bound by limitations and would face extreme difficulty in code maintenance and scalability, especially when working on large projects involving extensive code and multiple CSS stylesheets. This is where CSS Preprocessors come to the rescue.
A CSS Preprocessor is a tool used to extend the basic functionality of default vanilla CSS through its own scripting language. It helps us to use complex logical syntax like – variables, functions, mixins, code nesting, and inheritance to name a few, supercharging your vanilla CSS. By using CSS Preprocessors, you can seamlessly automate menial tasks, build reusable code snippets, avoid code repetition and bloating and write nested code blocks that are well organized and easy to read.
However, browsers can only understand native vanilla CSS code and will be unable to interpret the CSS Preprocessor syntax. Therefore, the complex and advanced Preprocessor syntax needs to be first compiled into native CSS syntax which can then be interpreted by the browsers to avoid cross browser compatibility issues. While different Preprocessors have their own unique syntaxes, eventually all of them are compiled to the same native CSS code.
Moving forward in the article, we will take a look at the 3 most popular CSS Preprocessors currently being used by developers around the world i.e Sass, LESS, and Stylus.
Before you decide the winner between Sass vs LESS vs Stylus, let us get to know them in detail first.
Sass – Syntactically Awesome Style Sheets
Sass is the acronym for “Syntactically Awesome Style Sheets”. Sass is not only the most popular CSS Preprocessor in the world but also one of the oldest, launched in 2006 by Hampton Catlin and later developed by Natalie Weizenbaum.
Although Sass is written in Ruby language, a Precompiler LibSass allows Sass to be parsed in other languages and decouple it from Ruby. Sass has a massive active community and extensive learning resources available on the net for beginners. Thanks to its maturity, stability and powerful logical prowess, Sass has established itself to the forefront of CSS Preprocessor ahead of its rival peers.
Sass can be written in 2 syntaxes either using Sass or SCSS. What is the difference between the two? Let’s find out.
Syntax Declaration: Sass vs SCSS
SCSS stands for Sassy CSS. Unlike Sass, SCSS is not based on
indentation.
.sass extension is used as original syntax for Sass, while SCSS
offers a newer syntax with .scss extension.
Unlike Sass, SCSS has curly braces and semicolons, just like CSS.
Contrary to SCSS, Sass is difficult to read as it is quite deviant
from CSS. Which is why SCSS it the more recommended Sass syntax as it
is easier to read and closely resembles Native CSS while at the same
time enjoying with power of Sass.
Consider the example below with Sass vs SCSS syntax along with Compiled CSS code.
Sass SYNTAX
$font-color: #fff
$bg-color: #00f
#box
color: $font-color
background: $bg-color
SCSS SYNTAX
$font-color: #fff;
$bg-color: #00f;
#box{
color: $font-color;
background: $bg-color;
}
In both cases, be it Sass or SCSS, the compiled CSS code will be the same –
#box {
color: #fff;
background: #00f;
Usage of Sass
Arguably the most Popular front end framework Bootstrap is written in Sass. Up until version 3, Bootstrap was written in LESS but bootstrap 4 adopted Sass and boosted its popularity. A few of the big companies using Sass are – Zapier, Uber, Airbnb and Kickstarter.
LESS – Leaner Style Sheets
LESS is an acronym for “Leaner Stylesheets”. It was released in 2009 by Alexis Sellier, 3 years after the initial launch of Sass in 2006. While Sass is written in Ruby, LESS is written JavaScript. In fact, LESS is a JavaScript library that extends the functionality of native vanilla CSS with mixins, variables, nesting and rule set loop. Sass vs LESS has been a heated debate. It is no surprise that LESS is the strongest competitor to Sass and has the second-largest user base. However, When bootstrap dumped LESS in favor of Sass with the launch of Bootstrap 4, LESS has waned in popularity. One of the few disadvantages of LESS over Sass is that it does not support functions. Unlike Sass, LESS uses # to declare variables which might cause confusion with #media and #keyframes. However, One key advantage of LESS over Sass and Stylus or any other preprocessors, is the ease of adding it in your project. You can do that either by using NPM or by incorporating Less.js file.
Syntax Declaration: LESS
Uses .less extension. Syntax of LESS is quite similar to SCSS with the exception that for declaring variables, instead of $ sign, LESS uses #.
#font-color: #fff;
#bg-color: #00f
#box{
color: #font-color;
background: #bg-color;
}
COMPILED CSS
#box {
color: #fff;
background: #00f;
}
Usage Of LESS
The popular Bootstrap framework until the launch of version 4 was written in LESS. However, another popular framework called SEMANTIC UI is still written in LESS. Among the big companies using Sass are – Indiegogo, Patreon, and WeChat
Stylus
The stylus was launched in 2010 by former Node JS developer TJ Holowaychuk, nearly 4 years after the release of Sass and 1 year after the release of LESS. The stylus is written Node JS and fits perfectly with JS stack. The stylus was heavily influenced by the logical prowess of the Sass and simplicity of LESS. Even though Stylus is still popular with Node JS developers, it hasn’t managed to carve out a sizeable share for itself. One advantage of Stylus over Sass or LESS, is that it is armed with extremely powerful built-in functions and is capable of handling heavy computing.
Syntax Declaration: Stylus
Uses .styl extension. Stylus offers a great deal of flexibility in writing syntax, supports native CSS as well as allows omission of brackets colons and semicolons. Also, note that Stylus does not use # or $ symbols for defining variables. Instead, Stylus uses the assignment operators to indicate a variable declaration.
STYLUS SYNTAX WRITTEN LIKE NATIVE CSS
font-color = #fff;
bg-color = #00f;
#box {
color: font-color;
background: bg-color;
}
OR
STYLUS SYNTAX WITHOUT CURLY BRACES
font-color = #fff;
bg-color = #00f;
#box
color: font-color;
background: bg-color;
OR
STYLUS SYNTAX WITHOUT COLONS AND SEMICOLONS
font-color = #fff
bg-color = #00f
#box
color font-color
background bg-color
And this is less
#primarycolor: #ffffff;
#width: 800px;
body{
width: #width;
color: #primarycolor;
.content{
width: #width;
background:#primarycolor;
}
}
Sass is a language that provides features to make it easier to deal with complex styling compared to editing raw .css. An example of such a feature is allowing definition of variables that can be re-used in different styles.
The language has two alternative syntaxes:
A JSON like syntax that is kept in files ending with .scss
A YAML like syntax that is kept in files ending with .sass
Either of these must be compiled to .css files which are recognized by browsers.
See https://sass-lang.com/ for further information.
How can you use css mixins based on an existing library? Example: Consider you want to create a new css class based on the bootstrap btn btn-success classes. It might look like:
.disabled-button {
#mixin .btn;
#mixin .btn-success;
#mixin .disabled;
color:red;
}
Less/Sass are capable of doing such kind of things when you define the classes btn or btn-success yourself, but how do you deal with it when it comes from bootstrap (or another css framework) ?
If you can add LESS compilation into your workflow, you can achieve this easily with its #import (reference) and :extend(x all). Without needing to learn anything more about LESS, you'd do
#import (reference) "bootstrap.less"; // this file is included with bootstrap. `(reference)` means it will only pull in the styles you ask it for, so you could continue using this even if you switch to another framework and don't want to include all of bootstrap
.disabled-button:extend(.button all, .button-success all, .disabled all) {} // pulls in the `.button` styles, `.button-success` styles, and `.disabled` styles
.disabled-button {color:red} // adds on your styles
Explanation of LESS's :extend(all) and relevant documentation links are in this answer
Since CSS is valid LESS, you wouldn't have to make any other changes to your stylesheet. Okay, so how do you add LESS compilation to your workflow? The simplest solution is described in LESS's "Command Line Useage" documentation, which boils down to installing less (once)
$ npm install less -g
and then running lessc, the less compiler
$ lessc my-styles.less my-compiled-styles.css
Somewhere I saw this structure of CSS document:
header {
.navigation {
a {
text-decoration: none;
}
}
}
If I will try it in my CSS file, it doesn't work.
What is needed for ability to write this code?
Thank you
This looks like LESS CSS http://lesscss.org/
You have to import javascript file less.js into your page.
Now compile your css file and than apply Mr #ozkanozlu is right way
just do this
header {.navigation{a{text-decoration: none;}}}
The code you've quoted is not actually CSS, it is a language called LESS, which compiles to CSS; it is a CSS pre-processor. It is designed to make CSS easier to work with, but it needs to be converted to pure CSS before it will actually work in a browser.
LESS can be compiled to CSS before deployment -- ie so you work on LESS code, but the user sees standard CSS -- or provided to the browser as LESS, but with the less.js also compiler included in the page. For performance reasons, I would always prefer the first of those options.
Other similar languages also exist -- see SASS for example. You can see a comparison of SASS vs LESS here: http://css-tricks.com/sass-vs-less/
The question pretty much says it all.
For instance, if I were using, say, Twitter Bootstrap, could I define classes in my own SASS stylesheet that inherit from Bootstrap's CSS classes? Or does inheritance in SASS only work within the scope of a single file?
YES! its possible.
If you want all <button> elements to inherit the .btn class from Twitter Bootstrap's Default buttons
In your styles.scss file you would have to first import _bootstrap.scss:
#import "_bootstrap.scss";
Then below the import:
button { #extend .btn; }
**I might be mistaken, but if I get what you're trying to do, can't you just use the #extend .classname; command inside the element that you'd want to extend? Naturally, you should only modify your own code to preserve updatability.
To my knowledge, you have to use #import of the file containing the classes you want to use into your SASS file in order to utilize them in that file. However, I am not a SASS/SCSS expert, so someone may know of another way to remotely use them that I am not aware of.
Just as the accepted answer has shown this is possible with #import, however #import has been deprecated by sass
The Sass team discourages the continued use of the #import rule. Sass will gradually phase it out over the next few years, and eventually remove it from the language entirely. Prefer the #use rule instead.
The #use rule is better suited for use now, since it does not pollute the scope of the importing (user) module. unfortunately at the time of writing the use rule is only implemented in Dart sass.