Javascript Singleton Object

Have you come across a problem where you have to create an object that can only be initialized once and you want to reuse that object throughout your whole application? Well maybe you haven't but I actually came across that problem the other day and here's the solution for it:

function singleton() {
 var instance = (function() {
   var privateVar;

   function privateMethod () {
     // ...
   }

   return { // public interface
     publicMethod1: function () {
         // private members can be accessed here
      },
     publicMethod2: function () {
       // ...
     }
   };
 })();

 singleton = function () { // re-define the function for subsequent calls
   return instance;
 };

 return singleton(); // call the new function
}

Solution given by CMS on Stack overflow(http://stackoverflow.com/questions/1895635/javascript-singleton-question)

Get number of weeks within fiscal year

The other day I found myself looking for a solution to find the week number we are in within a given fiscal year. Here's the solution I came up with with a snippet from my code:

Date.prototype.getWeek = function (dowOffset)
{
/*getWeek() was developed by Nick Baicoianu at MeanFreePath: http://www.meanfreepath.com */
dowOffset = typeof(dowOffset) == 'int' ? dowOffset : 0; //default dowOffset to zero
var newYear = new Date(this.getFullYear(),0,1);
var day = newYear.getDay() - dowOffset; //the day of week the year begins on
day = (day >= 0 ? day : day + 7);
var daynum = Math.floor((this.getTime() - newYear.getTime() - (this.getTimezoneOffset()-newYear.getTimezoneOffset())*60000)/86400000) + 1;
var weeknum;
//if the year starts before the middle of a week
if(day < 4)
{
weeknum = Math.floor((daynum+day-1)/7) + 1;
if(weeknum > 52)
{
nYear = new Date(this.getFullYear() + 1,0,1);
nday = nYear.getDay() - dowOffset;
nday = nday >= 0 ? nday : nday + 7;
/*if the next year starts before the middle of
the week, it is week #1 of that year*/
weeknum = nday < 4 ? 1 : 53;
}
}
else
{
weeknum = Math.floor((daynum+day-1)/7);
}
return weeknum;
}
var todaysDate = new Date();
var currentFiscalYear = todaysDate.getFullYear() - 1;
var numberWeeks;
if(todaysDate.getMonth() > 8 && todaysDate.getMonth() < 11)
{
currentFiscalYear = todaysDate.getFullYear();
}
var beginFiscalDate = new Date();
beginFiscalDate.setFullYear(currentFiscalYear,8,1);
var endFiscalDate = new Date();
endFiscalDate.setFullYear(currentFiscalYear+1,7,31);
var currYearBegFiscalYear = new Date();
currYearBegFiscalYear.setFullYear(todaysDate.getFullYear(), 8,1);
if(todaysDate.getFullYear() > beginFiscalDate.getFullYear()) //Check to see if today comes after september of the current year
{
var decFiscalYear = new Date();
decFiscalYear.setFullYear(currentFiscalYear,11,31);
numberWeeks = todaysDate.getWeek() + (decFiscalYear.getWeek() - beginFiscalDate.getWeek());
}
else
{
numberWeeks = todaysDate.getWeek() - beginFiscalDate.getWeek();
}

Mimic mySQL's LIMIT command in Oracle

I have struggled in the past and have heard of people struggling with writing a SQL statement in Oracle that would mimic mySQL's command LIMIT.

LIMIT doesn't exist in Oracle and there are two ways of displaying the range of records you want from a table. The first one is to use PLSQL. I'm not going to get into details here but all you have to do is do a SELECT statement INTO a CURSOR datatype, iterate your cursor and exit when your loop counter hits the number of rows you want.

As you can see this solution is not very effective and the best way of doing this is by creating a simple statement using the rownum column.

For instance, if you wanted to select the 10 first items from the item table you would do the following:

SELECT * FROM item WHERE rownnum < 11;

This should return the first 10 rows.