javascript - Run code once a day

Question

I was just wondering if it is possible to have a javascript for loop that only iterates through the loop once a day i.e. when the date changes?

for(i=0; i < myArray.length; i++){

    alert(myArray[i]);

}

So in the above loop, let it run, and freeze it or something only till the data changes, and the do another iteration, and just keep on doing that.. You know what I mean.

Thanks in advance!

Answer 1

Using localStorage is the best way to go when you don't have a server, since the javascript code might restarted (by closing the tab and re-opening), therefore loosing the previous state.

Method below is more bulletproof:

// checks if one day has passed. 
function hasOneDayPassed()
  // get today's date. eg: "7/37/2007"
  var date = new Date().toLocaleDateString();

  // if there's a date in localstorage and it's equal to the above: 
  // inferring a day has yet to pass since both dates are equal.
  if( localStorage.yourapp_date == date ) 
      return false;

  // this portion of logic occurs when a day has passed
  localStorage.yourapp_date = date;
  return true;
}


// some function which should run once a day
function runOncePerDay(){
  if( !hasOneDayPassed() ) return false;

  // your code below
  alert('Good morning!');
}


runOncePerDay(); // run the code
runOncePerDay(); // does not run the code