myths about css pre processors

Myths of CSS Preprocessors

Ramon Lapenta - @ramono - #sass

About me

•Frontend developer @ Cyber-Duck Ltd

•Making websites for over 10 years

•Love what I do for a living

•Love to talk about it

What are CSS Preprocessors?

•A way of adding functionality to CSS in the form of mixins, extends, functions.

What are CSS Preprocessors?

•A way of reducing development time by using variables and nesting rules.

Usage stats: Europe

Usage stats: America

Usage stats: America

Why use preprocessors?

1. CSS is repetitive

2. CSS doesn’t have variables

3. Inflexible, limited reusability

4. Complex websites are hard to maintain

The Myths

1.Adds complexity to the development process

2.You lose control over the final code

3.Adds overhead to the website

4.Adds extra dependencies to your workflow

5.Too hard to debug

The Myths

God, SCSS looks like JavaScript and PHP mated in a drunken state.

Christian Heilmann

Bull!The Famous Bull Of Wall Street -

http://goo.gl/kKsghb

Lets debunk the myths!

Myth: Complexity

•Nesting is a natural way of coding

•Named variables are easier to manage than individual values like colours (E.g. #0E2740)

•You don’t have to use all the functionality

Myth: Lose control

•If your CSS code is currently horrible, your Sass will undoubtedly be horrible

•Sass doesn’t write code by itself

•Use expanded output option during development

Myth: Overhead

•Compiled file is just plain CSS

•Automatically minify/compress

•Easy to add (or remove) vendor evil prefixes

•Seamless file concatenation

Myth: Dependencies

•Your current set up has many dependencies

•If you don’t use a pre-processor, you need a post-processor

•Many tools are available for free, for every platform

Myth: Hard to debug

•Organised code shouldn’t be hard to debug

•There are ways

•It’s getting better

•The cost is low compared to the benefit

Resources & Tools

Documentation

•All three major pre-processors have excellent documentation online

•Tutorials available

•Videos everywhere

Graphic Tools

• Codekit (http://incident57.com/codekit/)

• Prepros (http://alphapixels.com/prepros/)

• Compass (http://compass.kkbox.com)

• Hammer (http://hammerformac.com)

• Koala (http://koala-app.com)

• Mixture (http://mixture.io)

LiveReload (http://livereload.com)

Scout (http://mhs.github.io/scout-app/)

Crunch (http://crunchapp.net)

SimpleLess (http://wearekiss.com/simpless)

WinLess (http://winless.org)

LessApp (http://incident57.com/less/)

Other tools

•Brunch.io

•Grunt!

•Buildr

•Gulp

•Command line (it’s not hard)

$ sass --watch file.scss:file.css

$ sass --watch scss:css

Watch a file

Watch a folder

Techniques & Tips

Debug: —debug-info

•Debug info flag tells you with a comment where the rule is located in the source file.

•Available only up to Sass 3.2

$ sass --watch —style expanded —debug-info scss:css

Watch a folder

/* _head.scss line: 24 */.head { background-color: darkslateblue;}

Output

Debug: Chrome inspector

• Chrome 30+ includes Sourcemap (Sass 3.3 and Less 1.5+) support by default

• Stylus considering it

Debug: Chrome inspector

•Sourcemaps creates a map of your CSS

•Available only on Sass 3.3+

$ lessc common.less > common.css

Watch the folder

common.css common.map

Output

Debug: File organisation

•Divide and conquer

•Master the @import rules and file concatenation

•It’s easier to find a rule in a small file

public/ assets/ css/ styles.css img/ js/ scss/ _carousel.scss _contact.scss _grid.scss _home.scss _typo.scss styles.scss

Tip: File organisation

•Import within media queries so don’t repeat media queries

@media (max-width: 599px) { @import “small/base.scss”; }

•Make one file by component / section with all its media queries

Tip: Mixins

•Mixins are parametrisable snippets of code

@mixin box($type: border-box) {box-sizing: $type;-ms-box-sizing: $type;-moz-box-sizing: $type;-webkit-box-sizing: $type;

}

.box { padding: 20px;

width: 100%;@include box(border-box);

}

Tip: Mixins

•Easy way to add prefixes .box {

padding: 20px;width: 100%;box-sizing: border-box;-ms-box-sizing: border-box;-moz-box-sizing: border-box;-webkit-box-sizing: border-box;

}

Tip: Extends

•Extends allows you to alter rules without repeating code

•Use % to create a rule that outputs code only when extended.

.go { color: $white; padding: 5px 10px; border-radius: 5px; text-decoration: none; font-size: 1em; text-transform: uppercase; background-color: $green; } .cancel { @extend .go; background-color: $red; }

Tip: Extends

•Clever separation .go, .cancel {

color: white; padding: 5px 10px; border-radius: 5px; text-decoration: none; font-size: 1em; text-transform: uppercase; background-color: green; } .cancel { background-color: red; }

Tip: Nesting

•Nesting feels right

•It’s easy and you write less

.box { float: right;

footer {padding: 20px;

.btn { color: $white; }

} }

Tip: Nesting

•Easy to get carried away

•Can bring over-specificity issues

/ Compiles to .box { float: right; } .box footer { padding: 20px; } .box footer .btn { color: white; }

Tip: Github resources

•Tons of resources:Mixins, frameworks, libraries, tutorials,

Tip pitch: hoisin.scss

•Light & extensible

•Responsive

•Doesn’t make any design assumptions

•Mobile first, Content first, Performance first

•http://cyber-duck.github.io/hoisin.scss/

Which one is the best?

•Sass!

•All have about the same functionality

•Ensure it fits with your workflow

•Compatibility with existing code

•What feels better to you?

The Myths

1. Adds complexity to the development process

2. You lose control over the final code

3. Adds overhead to the website

4. Adds extra dependencies to your workflow

5. Too hard to debug

Final Considerations

•If you are a CSS beginner

•You need to know how CSS works before using a pre-processor

•Source Control: ignore compiled / compile on deployment

Thanks!Ramon Lapenta - @ramono - sxsw.com/rate