September 2007 Archives
September 28, 2007
Padding zero in Javascript
To display a number x in 2 digits with padding zero in the front, here's the snippet to do so:
String("0" + x).slice(-2);
To display 5 digits with padding zeros, it'll be:
String("0000" + x).slice(-5);
The number of zero can be parameterized, of course:
var padding_zero = function(x, n) {
var zeros = repeat("0", n);
return String(zeros + x).slice(-1 * n)
}
The function repeat is the string repeater defined in here.
But these definitions doesn't check the original number if it's longer then n digits. Calling padding_zero(357, 2) will give you 57. Neither does it check if its parameters are numbers or not. (Easy and may not be a big issue depends on what you want.)
And of course, you can pad something other than zero. For example, you can pad up to 5 number of
before
. They are just two different img strings anyway:
// pad up to n Ys before X.
var pad = function(x, n, y) {
var zeros = repeat(y, n);
return String(zeros + x).slice(-1 * n);
}
So the code to generate a line of 5 rating stars may just looks like:
pad("111", 5, "0).replace(/1/g, star_img).replace(/0/g, empty_star_img);
The idea here is to generate something like "11100" first, then replace them with img tags.
All these functions assumes x,y variables are only one character to work properly because I use slice() function on String classes. To make it more general, should probably use Array.
Labels: format, javascript, number, string
September 22, 2007
String repeat in JavaScript, and as a jQuery extension.
function repeat(str, i) {
if (isNaN(i) || i <= 0) return "";
return str + repeat(str, i-1);
}
Putting it down as a jquery extension, it becomes this snippet:
(function($){
$.extend({
repeat: function(str, i) {
if (isNaN(i) || i == 0) return "";
return str + $.repeat(str, i-1);
}
})
})(jQuery);
It's used like this:
var rating = 3; var star = "<img src='star.gif'>";// Show some number of stars based on rating.
$("#rating").html( $.repeat(star, rating) )
Labels: javascript, jquery
The Hidden Cameras - Boys Of Melody
音樂在 The Hidden Cameras - Boys Of Melody
這 MV 也很有意思。身形高大聲音溫和的左手人吉他手相當地吸引我。
怎麼說呢,雖然說這音樂可能太「甜」了一點,也沒有什麼結構,不過在連續長時間工作之餘,這真是奢華的一品啊。
Labels: music
September 19, 2007
A simple Perlbal load balancer config for mongrel cluster
mongrel_cluster.yml:
--- log_file: log/mongrel.log port: 4000 pid_file: tmp/pids/mongrel.pid servers: 5
load-balancer.conf for Perlbal
CREATE POOL my_servers POOL my_servers ADD 127.0.0.1:4000 POOL my_servers ADD 127.0.0.1:4001 POOL my_servers ADD 127.0.0.1:4002 POOL my_servers ADD 127.0.0.1:4003 POOL my_servers ADD 127.0.0.1:4004CREATE SERVICE balancer
SET listen = 0.0.0.0:3000
SET role = reverse_proxy
SET pool = my_servers
SET persist_client = off
SET persist_backend = off
SET verify_backend = offENABLE balancer