css pattern libraries

PATTERN LIBRARIES CSSPATTERN LIBRARIES

Who is this guy?

Began in the web in 1995 Full CSS sites in 2002 Skills: UX, front-end dev, training Recently: CSS pattern libraries

I have helped develop HTML/ CSS pattern libraries for very large sites (media and university sites) and complex applications (banking applications).

In some cases, there are literally hundreds of CSS, SCSS or LESS les to review and optimise as part of the process.

pages Moving away from

A few years ago, many front end developers approached websites and web applications as a series of pages.

Pages were often designed and built as complete entities. This meant that page components were often closely tied to their relevant pages.

More recently, the focus has shifted from full page layouts to re-usable components.

A re-usable component could be a layout grid structure, a button, an input, a drop-down, a menu, a heading, a table, or even a pullquote.

pattern libraries HTML/CSS

HTML/CSS pattern libraries are used to resolve commonly used interface components. These components are created as HTML and CSS code and documented, so that they can be easily re-used as needed.

The terms style guide and pattern library are often used interchangeably.

A style guide is a set of standards for implementing the overall design, and can include corporate branding, color schemes, layout and more.

Style guides are used to ensure uniformity of the design or brand across all aspects of the website or application.

On the other hand, HTML/CSS pattern libraries generally document code components for all aspects of the website or application.

On larger web projects, style guides and HTML/CSS pattern libraries are generally separate entities.

For smaller web projects, style guides and pattern libraries are often combined into one overall entity.

cons? Pros and

Why use a pattern library at all? ! Easier to build sites Easier to maintain sites Easier to hand over Better workow Shared vocabulary Promotes consistency

What are the downsides? ! Time-consuming to write Often done post-project Serve current need only

Pre-existing pattern libraries

There are a wide range of pre-existing pattern libraries available today.

Some of these pattern libraries have a simple purpose - such as responsive grid systems.

Grid-based CSS libraries 1140 CSS Grid Mueller Grid System Responsive Grid System Responsive Grid System Less Framework 960 Grid System Susy 320 and up http://cssgrid.net/ http://www.muellergridsystem.com/ http://www.responsivegridsystem.com/ http://responsive.gs/ http://lessframework.com/ http://960.gs/ http://susy.oddbird.net/ https://github.com/malarkey/320andup

Others are considered full frameworks that oer a wide range of components.

These can include: ! Reset styles Grid systems Typography styles Browser xes Common user-interface component styles

Complex CSS libraries Bootstrap Foundation Skeleton YAML Inuit Kraken GumbyFramework http://twitter.github.com/bootstrap/ http://foundation.zurb.com/ http://www.getskeleton.com/ http://www.yaml.de/ https://github.com/csswizardry/inuit.css/ https://github.com/cferdinandi/kraken http://gumbyframework.com/

There are some great benets to using an existing framework: ! ready-to-use solution can pick & choose components easy implementation quick prototyping great for teams

There may also be some downsides: ! may not suit your project no need for a complex library someone elses conventions generic look

Bootstrap

Bootstrap vs. mid-range website

Bootstrap vs. University data site

Bootstrap vs. Banking application

Should you use a pre-existing framework? It depends on the needs of the site and your team. There is no one answer.

Assuming you want to create your own CSS pattern library, how do you go about it?

abstraction Understanding

Abstraction is essential to any CSS pattern library.

The process involves: ! looking for components that may be repeated within the layout dening their characteristics creating HTML/CSS patterns for them 1. ! 2. 3.

An example: coloured boxes

These boxes look like they have similar characteristics. If they were resolved into a pattern, this would make our HTML and CSS more ecient.

What are the key things to keep in mind when creating any pattern?

Avoid using IDs

All patterns needs to be class- based so they can appear as many times as needed within an HTML document.

/* avoid */! #signup-box { }!

Avoid naming based on content

We should avoid naming patterns based on the content, as we want to reuse these patterns often within the layout.

/* avoid */! .signup { }! .member { }! .member-news { }! .wiki { }! .support { }! .database { }! ! /* preferred */! .box { }

Avoid location- based styles

All patterns should work regardless of where theyre placed within the layout.

/* avoid */! .sidebar .box { }! .main .box { }! ! /* preferred */! .box { }

Avoid widths

Ideally, patterns should avoid dening widths. Patterns should be allowed to spread to the width of any parent container.

/* avoid */! .box-wide { width: 500px; }! .box-medium { width: 240px; }! .box-small { width: 120px; }! ! /* preferred */! .box { /* no width defined */ }

Keep patterns as simple as possible

Patterns should be dened as simply as possible. Otherwise they can become restrictive.

.box! {! ! border-bottom: 5px solid #C8C8C8;! ! background-color: #e6e6e6;! ! /* may not be suitable */! ! margin-bottom: 1em;! }

Dont undo

Patterns should not be written to undo other rules. For example, the element:

We could be tempted to style the element with a coloured background - as it looks like this is the default appearance for all elements.

/* default style */! h3! {! ! padding: 1em;! ! color: white;! ! background-color: red;! }

But what happens if we needed to use an element later, and it doesnt have a background-color? We might have to write a rule to undo our previous one.

/* default style */! h3! {! ! padding: 1em;! ! color: white;! ! background-color: red;! }! ! /* undoing default style */! .no-background ! {! ! padding: 0;! ! color: #000;! ! background-color: none;! }!

It is best to avoid over-styling elements or patterns so that they do not have to be undone later.

/* default style */! h3! {! }! ! /* only when background needed */! .class-name! {! ! padding: 1em;! ! color: white;! ! background-color: red;! }!

Avoid dependency on HTML structure

Patterns should not rely on the HTML structure. What happens if the structure changes in some instances - like a dierent heading level being used?

! ! !
! !
! ! !
! ! ! /* avoid if possible */! .box h3, .box h4! {! ! padding: 10px; ! ! background-color: orange; ! }! !

It is always better to create a class-based pattern for any specic styling needs.

! ! !
! !
! ! !
! ! ! /* preferred */! .box-heading! {! ! padding: 10px; ! ! background-color: orange; ! }!

Modules, modifiers & descendants

How can we let developers know that our new class called box-heading relates to the box class?

! ! !
!

We could use a naming convention that was originally dened as part of BEM: ! http://bem.info/

And then extended by Nicolas Gallagher: ! http://nicolasgallagher.com/about-html-semantics- front-end-architecture/

And then modied slightly again by Harry Roberts: ! http://csswizardry.com/2013/01/mindbemding- getting-your-head-round-bem-syntax/

This naming convention is based on the idea that page layouts can be broken down into a series of re-usable modules.

If a module needs to be modied or extended, a module modier would be used.

If a module has child elements that need to be styled, a module descendant could be used.

These dierent types of class names need to be relatable and recognisable.

/* Module */! .module-name {}! ! /* Module modifier*/! .module-name--modifier-name {}! ! /* Module descendant*/! .module-name__descendant-name {}! ! /* Module descendant modifier*/! .module-name__descendant--modifier {}!

! ! ! ! ! ! !
! ! !
! ! !
! ! !
!

Module descendants

With this naming convention, we can now add two module descendants to our HTML markup:

!
! ! ! ! ! ! ! ! ! ! !
!

.box! {! ! margin-bottom: 1em;! ! border-bottom: 5px solid #C8C8C8;! ! background-color: #e6e6e6;! }! ! .box__heading! {! ! margin: 0;! ! padding: 10px 15px;! ! text-transform: uppercase;! }! ! .box__content { margin: 15px; }!

Module modifiers

But what about the boxes that are very similar, but have some unique characteristics - like the decorative cog image?

If we needed to modify or extend the original module, we would create a modier class name.

!
! ! ! ! !
!

However, in this case, we need to modify the box__content class. We need to create a module descendant modier.

!
! ! ! ! !
!

.box__content--cog! {! ! padding-right: 100px;! ! background-image: url(cog.png);! ! background-repeat: no-repeat;! ! background-position: 100% 0;! }!

Helper classes

In one of the boxes, there is a piece of text that is aligned to the right. How do we solve this?

We could make it another module descendant - and apply this to the link.

.box__link {}! ! ! !
! ! ! !
! ! ! ! !
!
! !

Or we could use a dierent type of class, called a helper or utility class.

Nicolas Gallaghers SUIT CSS includes a set of classes called utilities. ! https://github.com/suitcss/suit

/* Utility classes */! .u-utilityName {}! ! ! ! ! ! ! !
! ! ! ! !
! !

Bootstrap also uses these types of classes, but calls them helper classes. ! http://getbootstrap.com/css/#helper-classes

/* Utility classes */! .text-muted { color: #777; } ! .text-primary { color: #428bca; }! .text-success { color: #3c763d; }! ! ! !
...
!
...
!
...

These types of classes are designed to be added to elements where needed, without having to resort to styling elements individually.

/* Helper classes */! .h-text-right { text-align: right; }! ! ! ! ! !
! ! More!
!

For front-end developers who grew up in the keep your markup clean era, these classes could be considered the work of Satan.

Ive found them to be invaluable - when you need to add a single function to an element without having to create a specic class.

Theme classes

In 2011, Jonathan Snook introduced SMACSS. One of the key principles is to categorise CSS rules into ve dierent categories. ! https://smacss.com/

Base - HTML elements Layout - grids Module - reusable components State - states of modules etc Theme - theming modules etc

These categories are a great way to break up huge chunks of CSS rules into manageable sections.

We could use one of these categories - theme styles - to dene the background-colors on our headings.

! ! ! !

.bgcolor-red, .bgcolor-blue, .bgcolor- orange, .bgcolor-grey { color: #fff; }! ! .bgcolor-red ! { background-color: #B21F24; }! ! .bgcolor-blue ! { background-color: #1D5980; }! ! .bgcolor-orange ! { background-color: #C56F00; }! ! .bgcolor-grey ! { background-color: #444445; }

Tips Pattern library

Here are some tips on the overall approach to CSS pattern libraries.

Smallest to largest

In mid 2013, Brad Frost introduced Atomic Design - a methodology for creating design systems with ve distinct levels in atomic design. ! http://bradfrostweb.com/blog/post/atomic-web- design/

Atoms - HTML elements Molecules - groups of atoms Organisms - groups of molecules Templates - groups of organisms Pages - instances of templates

Atomic design denes the process as starting from smallest components and building to largest.

Ideally, large components should not need to be dened in a pattern library as they should be build up, like lego, from smaller components.

Class names

Establish a class naming convention as early as possible in the process. Then document this convention and enforce it!

Intuitive class names

Make sure any class naming convention is easy for others to follow. I have worked on projects where teams are constantly changing, so quick take-up is critical.

Keep it simple

Ive worked on projects where the LESS architecture needs to be mapped out in spreadsheets in order for teams to understand. In almost all cases, this was unnecessary. Keep it as simple as possible.

Final thoughts?

Bottom line: HTML/CSS pattern libraries are an important tool for anyone doing CSS today no matter how large or small your website. Get out there and get busy!

Russ Weakley Max Design ! Site: maxdesign.com.au Twitter: twitter.com/russmaxdesign Slideshare: slideshare.net/maxdesign Linkedin: linkedin.com/in/russweakley