Taming CSS Selectors
Download as key, pdf30 likes3,186 views
From Nicole's presentation at the CSS Summit. This is brand new research regarding efficient CSS selector design. Practicing the rules outlined here will make your CSS lean, your site fast, and your maintenance minimal. A beautiful combination for people concerned with building performance into their sites.
More Related Content
What's hot (20)
Similar to Taming CSS Selectors (20)
More from Nicole Sullivan (13)
Recently uploaded (20)
Taming CSS Selectors
- 1. TAMING SELECTORS sanity for our stylesheets
- 2. SIZE OF THE CSS FILE AND IMPLIED HTTP REQUESTS are the biggest factor for CSS performance
- 3. REFLOWS AND RENDERING TIME are (much!) less important
- 4. DUPLICATION IS WORSE THAN STALE RULES because we have tools to deal with the later
- 5. DEFINE DEFAULT VALUES Don’t repeat this code in every object
- 6. #weatherModule h3{color:red;} #tabs h3{color:blue} DEFINE DEFAULT VALUES Don’t repeat this code in every object
- 7. X #weatherModule h3{color:red;} #tabs h3{color:blue} DEFINE DEFAULT VALUES Don’t repeat this code in every object
- 8. X #weatherModule h3{color:red;} #tabs h3{color:blue} DEFINE DEFAULT VALUES Don’t repeat this code in every object h1, .h1{...} h2, .h2{...} h3, .h3{...} h4, .h4{...} h5, .h5{...} h6, .h6{...}
- 9. DEFINE STRUCTURE IN A SEPARATE CLASS Don’t repeat this code in every object block inner hd bd ft
- 10. div.error{...} STYLE CLASSES rather than elements
- 11. X div.error{...} STYLE CLASSES rather than elements .error{ most of the code goes here }
- 12. X div.error{...} STYLE CLASSES rather than elements .error{ most of the code goes here } div.error{ } p.error{ exceptions only } em.error{ }
- 13. div{...} ul{...} p{..} AVOID STYLING ELEMENTS unless defining defaults
- 14. div{...} X ul{...} p{..} AVOID STYLING ELEMENTS unless defining defaults .error{...} .section{...} .products{...}
- 15. .myModule .inner b{...} .myModule2 b {...} GIVE RULES THE SAME STRENGTH Use cascade order to overwrite previous rules
- 16. X .myModule .inner b{...} .myModule2 b {...} GIVE RULES THE SAME STRENGTH Use cascade order to overwrite previous rules .myModule b{...} .myModule2 b {...}
- 17. .sidebar ul{...} .header ul {...} AVOID SPECIFYING LOCATION Apply classes to the object you wish to change
- 18. X .sidebar ul{...} .header ul {...} AVOID SPECIFYING LOCATION Apply classes to the object you wish to change .mainNav{...} .subNav {...}
- 19. AVOID OVERLY SPECIFIC CLASSES they’re all semantic, but limiting
- 20. AVOID OVERLY SPECIFIC CLASSES they’re all semantic, but limiting .vehicle{...} .motorcycle{...} .ducati{...} .ducatiMonster620{...} .nicolesDucatiMonster620{...}
- 21. AVOID OVERLY SPECIFIC CLASSES they’re all semantic, but limiting .vehicle{...} .motorcycle{...} .ducati{...} X .ducatiMonster620{...} .nicolesDucatiMonster620{...}
- 22. #myUniqueIdentifier{...} #myUniqueIdentifier2{...} AVOID SINGLETONS ids can only be used once in any given page Source: Chris Griego
- 23. X #myUniqueIdentifier{...} #myUniqueIdentifier2{...} AVOID SINGLETONS ids can only be used once in any given page Source: Chris Griego
- 24. Media Subheading Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. USE MIXINS to avoid repeating code Media Extended Subheading Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
- 25. .inner{...} .weatherMod .inner{...} .tr{...} .weatherMod .tr{...} .bl{...} .weatherMod .bl{...} ENCAPSULATION don’t access sub-nodes of an object directly inner
- 26. .inner{...} X .weatherMod .inner{...} .tr{...} .weatherMod .tr{...} .bl{...} .weatherMod .bl{...} ENCAPSULATION don’t access sub-nodes of an object directly inner