YUI on the go

1. YUI on the go How to include YUI components on demand Christian Heilmann Yahoo! Frontend Engineering Summit UK December 2007

2. Why use libraries?

3. Plan Use good Job Code library done

4. Without libraries:

5. Plan Browser Hell Code OS inconsistencies Forget about obscure bugs Cannot reproduce

6. > CVS commit > Conflict: > Too much fail error.

7. You.sacked = true

8. MCSE

9. “You want fries with that?”

10. Ergo: Libraries are good, mkay?

11. A common complaint.

12. “YUI is too big! If I want to build something on top of it, I need to include a lot of large files!”

13. yahoo.js – 4.6kb dom.js – 35kb event.js – 61kb reset.css – 0.5kb fonts.css – 0.6kb grids.css – 3kb 6 HTTP requests – 104.7kb

14. First Aid remedies: – Use the minified YUI versions

15. yahoo-min.js – 1kb dom-min.js – 10.2kb event-min.js – 13kb reset-min.css – 0.4kb fonts-min.css – 0.2kb grids-min.css – 2.4kb 6 HTTP requests – 27.2kb

16. First Aid remedies: – Use the minified YUI versions – Cut down on included YUI components by using the combined component includes.

17. yahoo-dom-event.js – 24.1kb reset-fonts-grids.css – 3.1kb 2 HTTP requests – 27.2kb

18. First Aid remedies: – Use the minified YUI versions – Cut down on included YUI components by using the combined component includes. – Use the hosted YUI versions.

19. This is all packing and level crunching.

20. What we really want is...

21. On-demand delivery

22. Why is that needed?

23. Use cases:

24. Use cases: – We don’t want to make users load things they don’t need.

25. Use cases: – We don’t want to make users load things they don’t need. – Distribution (badges, banners) works a lot better if it is one <script> and not 3.

26. Use cases: – We don’t want to make users load things they don’t need. – Distribution (badges, banners) works a lot better if it is one <script> and not 3. – We can offer implementers to trigger extra functionality with markup:

27. Use cases: – We don’t want to make users load things they don’t need. – Distribution (badges, banners) works a lot better if it is one <script> and not 3. – We can offer implementers to trigger extra functionality with markup: “add an ‘animated’ CSS class for smooth transitions”

28. Example?

29. <div class=quot;flickrbadgequot;> <p> <a href=quot;http://www.flickr.com/photos/11414938% 40N00quot;> My latest photos on flickr </a> </p> </div> <script src=quot;flickrbadgeloader.jsquot;></script> http://icant.co.uk/sandbox/flickrbadgev2/

32. How?

33. Supercool Solution: The YUI Loader http://developer.yahoo.com/yui/yuiloader

34. YUI Loader:

35. YUI Loader: – Knows about dependencies

36. YUI Loader: – Knows about dependencies – Automatically gets the newest hosted versions

37. YUI Loader: – Knows about dependencies – Automatically gets the newest hosted versions – Works without yahoo.js

38. YUI Loader: – Knows about dependencies – Automatically gets the newest hosted versions – Works without yahoo.js – Extendable with non-YUI components(!)

39. <script src=quot;http://yui.yahooapis.com/2.3.1/b uild/yuiloader/yuiloader-beta- min.jsquot;></script> <script> loader = new YAHOO.util.YUILoader(); loader.require('calendar','tabview'); loader.insert(function() { // Your code }); </script>

40. http://yuiblog.com/assets/pdf/cheatsheets/yuiloader.pdf

41. Other option – 11kb is too much!

42. Rolling your own The YAHOO_config way

43. YUI has an often forgotten configuration setting in YAHOO_config.

44. YUI has an often forgotten configuration setting in YAHOO_config. http://developer.yahoo.com/yui/yahoo/#config

45. YUI has an often forgotten configuration setting in YAHOO_config. No ww http://developer.yahoo.com/yui/yahoo/#config mo ith AW re ES OM E!

46. It allows you to define a listener function that gets notified every time a YUI component is loaded.

47. <script> function snitch(component){ console.log('can has YUI ' + component.name); }; YAHOO_config = { listener:snitch }; </script> <script src=quot;http://yui.yahooapis.com/2.3.1/build/ya hoo/yahoo-min.jsquot;></script> <script src=quot;http://yui.yahooapis.com/2.3.1/build/ev ent/event-min.jsquot;></script>

48. Using this in conjunction with your scripts and repeat calls of the “snitch” function allows you to dynamically include the YUI.

49. var myScript = function(){ // other code function addScript(url){ var s = document.createElement('script'); s.setAttribute('type', 'text/javascript'); s.setAttribute('src', url); document.getElementsByTagName('head')[0].appendChild(s); }; function YUIready(o){ if(typeof o === 'undefined'){ var APIurl = 'http://yui.yahooapis.com/2.3.1/' + 'build/yahoo-dom-event/' + 'yahoo-dom-event.js'; addScript(APIurl); } else { if(o.name === 'yahoo-dom-event'){ // YUI is ready } }; }; YUIready(); return { YUIready:YUIready }; }(); YAHOO_config = { listener:myScript.YUIready };

52. var myScript = function(){ // other code + function addScript(url){}; function YUIready(o){ if(typeof o === 'undefined'){ var APIurl = 'http://yui.yahooapis.com/2.3.1/' + 'build/yahoo-dom-event/' + 'yahoo-dom-event.js'; addScript(APIurl); } else { if(o.name === 'yahoo-dom-event'){ // YUI is ready } }; }; YUIready(); return { YUIready:YUIready }; }(); YAHOO_config = { listener:myScript.YUIready };

60. You can extend that to load different YUI components one after the other.

61. var myScript = function(){ // other code + function addScript(url){}; function YUIready(o){ if(typeof o === 'undefined'){ var APIurl = 'http://yui.yahooapis.com/2.3.1/' + 'build/yahoo-dom-event/' + 'yahoo-dom-event.js'; addScript(APIurl); } else { if(o.name === 'yahoo-dom-event'){ var url = 'http://yui.yahooapis.com/2.3.1/' + 'build/animation/' + 'animation-min.js'; addScript(url); } }; }; YUIready(); return { YUIready:YUIready }; }(); YAHOO_config = { listener:myScript.YUIready };

62. var myScript = function(){ // other code + function addScript(url){}; function YUIready(o){ + if(typeof o === 'undefined'){ } else { if(o.name === 'yahoo-dom-event'){ var url = 'http://yui.yahooapis.com/2.3.1/' + 'build/animation/' + 'animation-min.js'; addScript(url); }; if(o.name === 'animation'){ // done … }; }; }; YUIready(); return { YUIready:YUIready }; }(); YAHOO_config = { listener:myScript.YUIready };

63. You can also make it dependent on classes or IDs used in the document, or configuration options of your main script and many more things.

64. Have fun! Thanks!