The document discusses creating a timer object in JavaScript using the Ju.app.timer.create method. It initializes the timer with properties like timeEnd, timeCurrent, and a callback function that will log output when called. The timer is assigned to the variable aTimer. Later sections discuss tips for using timers, including differences between setTimeout and setInterval and how to avoid timer bugs.

1. new Timer
etai
var aTimer = Ju.app.timer.create(
{
timeEnd: timeEnd,
timeCurrent: timeCurrent,
container: theTimer,
style: 'simple',
callback: function(handler){
console.log(handler);
}
}
);

2. ‣
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3. WTF?
....

4. 1.
• ;
•

5. setInterval : 5mins / hour
setTimeout : 10min / hour
10+ / day

6. 2.
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7. 3.
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8. 3.
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10. -
a.
b.

11. -
a.
b.

12. -
b.

13. -
before:

14. -
a. innerHTML

15. -
b. replaceHTML
When innerHTML isn’t Fast Enough

16. -
before innerHTML replaceHTML
ff3.6 2600 ff3.6 600 ff3.6 3000
ie8 6100 ie8 900 ie8 4200
ie6 6300 ie6 1200 ie6 5500

17. -
<p class="dsec">.6</p>

18. -
dsec.gif

19. -
html

21. - “ ”
var aTimer = Ju.app.timer.create(
{
timeEnd: timeEnd,
timeCurrent: timeCurrent,
timeLeft: 0,
container: theTimer,
callback: function(handler){
alert(‘time’s up!’);
}
}
);
Ju.app.timer.remove(aTimer);

22. - “ ”

23. - “ ”

24. - “ ”

25. / Tips

26. / Tips - 1. vs timer
• timer
•
• setInterval?

27. / Tips - 1. vs timer
“ ”
“ ”

28. / Tips - 1. vs timer

29. / Tips - 1. vs timer

30. / Tips - 1. vs timer
=>
+

31. / Tips
- 2. setTimeout vs setInterval
“ bug”

32. / Tips
- 2. setTimeout vs setInterval
setTimeout
or
setInterval?

33. / Tips 2. setTimeout vs setInterval
How JavaScript Timers Work

34. / Tips
- 2. setTimeout vs setInterval
SetTimeout

37. Google I/O Conference: HTML5 Countdown Finale

38. Google I/O Conference: HTML5 Countdown Finale

39. checker
“ ”

40. Q /A