yeah, I liked the timestamp concept. Modified my code and worked perfectly :)
Thanks! -Regards *Amit Agarwal <http:///www.amitagrwal.com>* +91-779-822-8765 On Mon, Dec 20, 2010 at 3:35 PM, Shane Tomlinson <[email protected]> wrote: > I personally like to use timestamps over ints or rand, a timestamp is > ensured to be unique. If you use an int and in this session you had > "http://.....gif?1";, the next time the user goes into the app, they re-use > the integer 1, using the cache. And Math.random isn't as random as you want > it to be: > http://stackoverflow.com/questions/1062902/how-random-is-javascripts-math-random. > But a timestamp, that is going to be unique unless you reset your system's > clock. > > And performance wise, trying to optimize this is a premature-optimization. > Unless your request is called many many thousands of times a second, the > performance overhead of using a timestamp will be effectively 0. > > Check out: > https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getTime, > this returns the number of milliseconds since Jan 1, 1970, again, unless the > user resets their system clock, it is guaranteed to be unique. > > try requesting: "http://....gif?"; + ( new Date() ).getTime(); > > > On Mon, Dec 20, 2010 at 9:45 AM, Loic Giraudel <[email protected]>wrote: > >> Or for better performance a simple incremented int variable. >> >> >> On Mon, Dec 20, 2010 at 10:43, fernando trasvina <[email protected]>wrote: >> >>> use ?Math.random() on ur uri >>> or timestamp + Math.random() >>> >>> On Dec 20, 2010, at 3:35 AM, Amit Agarwal wrote: >>> >>> Hi every one, >>> >>> I need to poll an image using javascript and need to perform an action >>> once the image is found at its position. This is the code I have written for >>> this task. >>> >>> /*----Image handling script starts here----*/ >>> var beacon = new Image(); >>> >>> >>> >>> >>> >>> beacon.onload = function() { >>> >>> >>> console.log('Image found'); >>> console.log(this.width,this.height); >>> >>> >>> >>> >>> >>> window.clearInterval(timer); >>> }; >>> >>> >>> beacon.onerror = function(){ >>> console.log('Image not found'); >>> >>> >>> >>> >>> } >>> var timer = window.setInterval(function(){ >>> >>> >>> console.log('sending the request again'); >>> beacon.src = "http://www.google.co.in/logos/2010/lennon10-hp.gif";; >>> >>> >>> >>> >>> },2000); >>> /*----Image handling script ends here----*/ >>> >>> Problem is that, after one GET request, the response gets cached and >>> requests don't get sent everytime I set src. If you examine NET tab, it >>> sends request only on first src set and caches the response. >>> >>> I need to send a fresh request for image every time my code sets the src. >>> Any workarounds? >>> >>> -Regards >>> *Amit Agarwal <http:/www.amitagrwal.com>* >>> +91-779-822-8765 >>> >>> >>> -- >>> To view archived discussions from the original JSMentors Mailman list: >>> http://www.mail-archive.com/[email protected]/ >>> >>> To search via a non-Google archive, visit here: >>> http://www.mail-archive.com/[email protected]/ >>> >>> To unsubscribe from this group, send email to >>> [email protected] >>> >>> >>> -- >>> To view archived discussions from the original JSMentors Mailman list: >>> http://www.mail-archive.com/[email protected]/ >>> >>> To search via a non-Google archive, visit here: >>> http://www.mail-archive.com/[email protected]/ >>> >>> To unsubscribe from this group, send email to >>> [email protected]<jsmentors%[email protected]> >>> >> >> -- >> To view archived discussions from the original JSMentors Mailman list: >> http://www.mail-archive.com/[email protected]/ >> >> To search via a non-Google archive, visit here: >> http://www.mail-archive.com/[email protected]/ >> >> To unsubscribe from this group, send email to >> [email protected]<jsmentors%[email protected]> >> > > -- > To view archived discussions from the original JSMentors Mailman list: > http://www.mail-archive.com/[email protected]/ > > To search via a non-Google archive, visit here: > http://www.mail-archive.com/[email protected]/ > > To unsubscribe from this group, send email to > [email protected]<jsmentors%[email protected]> > -- To view archived discussions from the original JSMentors Mailman list: http://www.mail-archive.com/[email protected]/ To search via a non-Google archive, visit here: http://www.mail-archive.com/[email protected]/ To unsubscribe from this group, send email to [email protected]
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![http://www.google.co.in/logos/2010/lennon10-hp.gif"](https://www.google.co.in/logos/2010/lennon10-hp.gif"){kind=link}