Taming CSS Selectors
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The document emphasizes best practices for managing CSS performance by minimizing file size and duplication. It suggests defining default styles, using classes instead of element selectors, and maintaining a clear structure in stylesheets while avoiding overly specific classes and IDs. Additionally, it advocates for encapsulation and the use of mixins to enhance maintainability and reduce repetition.
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