cheatsheet-bemit.md

BEMIT cheatsheet

source: http://csswizardry.com/2015/03/more-transparent-ui-code-with-namespaces/

• o-: Object
  • Objects are abstract.
  • They can be used in any number of places (places you might not have seen).
  • Avoid modifying their styles.
  • Be careful around anything with a leading o-.
  • Examples: layout, wrappers, containers and other structural components
• c-: Component
  • Components are implementation-specific bits of UI.
  • They are quite safe to modify.
  • Anything with a leading c- is a specific thing.
  • Examples: property, user profile, gallery item…
• u-: Utility
  • Utilities are style heavyweights.
  • Never reassign to anything that carries a leading u-.
  • They commonly have a single responsibility.
  • They commonly use !important to ensure enforcement.
  • They’re only one step away from inline styles; use them sparingly.
  • Examples: column, clearfix,
• t-: Theme
  • Theme namespaces are very high-level.
  • They provide a context or scope for many other rules.
  • It’s useful to signal the current condition of the UI.
  • Examples: Modifiers changing font-size, colors consistently throughout the website…
• s-: Scope
  • Scopes are pretty rare: make triple sure you need them before using them.
  • They rely entirely on nesting, so make sure people are aware of this.
  • If you don’t know where to use them, you’re probably searching for something elsegit .
• is- & has-: State
  • States are very temporary.
  • Ensure that States are easily noticed and understood in our HTML.
  • Never write a bare State class.
  • Examples: open or closed menus, active or inactive tabs, etc.
• _, Hack
  • Hacks are ugly. Give them ugly classes.
  • Hacks should be temporary, do not reuse or bind onto their classes.
  • Keep an eye on the number of Hacks classes in your codebase.
  • Examples: isolated pixel-perfect properties, specific heights…
• js-: JavaScript
  • JavaScript and CSS are separate concerns. Use separate hooks for them.
  • Giving different teams/roles different hooks makes for safer collaboration.
  • “we should never have styling and behaviour bound to the same hooks”
  • Examples: Modal windows, tabs, dropdown menus…
• qa-: QA
  • Binding automated UI tests onto style hooks is too inexplicit. Don’t do it.
  • Bind tests onto dedicated test classes.
  • Ensure that any UI refactoring doesn’t affect the QA team’s hooks.