CODEWITHSUNDEEP
javascriptjqueryjsp
Balasaheb
Balasaheb

Reputation: 635

How do you compare the client date and server date?

I have a code that runs to select a date from calender, but I want to set the current_date to that of the server in the mentioned calender. And with a functionality that compares client_date with server_date.

Upvotes: 3

Views: 2351

Answers (4)

Peter Pajchl
Peter Pajchl

Reputation: 2709

One way of doing it is to pass the current date from your server script to the template, so when the pages renders, javascript can access it and make comparison. This has obvious issue - if the user will leave the page open till next day, the date will be out of date.

Other way is to use asynchronous call to your back-end and obtain the date from there.

Upvotes: 0

Aaron Digulla
Aaron Digulla

Reputation: 328674

That's possible. As suggested elsewhere, you should convert the dates to strings for two reasons:

  1. Easier to read/understand when you search for a bug
  2. The "current time" is always different between client and server

To send the current date to the client, you can use a hidden form field or an AJAX request or a web service or REST or JSON or JSONP or ... well, there are too many methods to do it.

To compare dates, convert the string to a Date object and then use the usual methods to compare them (compareTo() in Java and <,==,> in JavaScript).

Upvotes: 2

Reporter
Reporter

Reputation: 3948

The easiest way is to compare both dates with conversation to milliseconds. Both languages provides methods for it.

Javascript:

<script type="">
  var myDate = new Date();
  var milliseconds = myDate.getTime();
</script>

Java (JSP):

<script type="text/javascript">
<%!
    Date myJavaDate = new Date();
    long myJavaMilliseconds = 0L;
    myJavaMilliseconds = myJavaDate.getTime();
%>
 var myJavaMillisondsInJs = <%= myJavaMilliseconds %>;
</script>

/* Put code here to compare between those dates */

If you want to compare the dateas server side you have to submit the javatime to the server via Ajax or a form.

Upvotes: 0

Gunhan
Gunhan

Reputation: 7035

You can do it by using the following way:

In Java

public class YourJavaClass{
 public static String getServerDate()
 {
    Calendar cal = Calendar.getInstance();

    return cal.get(Calendar.YEAR) + "-" + cal.get(Calendar.MONTH) + "-" + cal.get(Calendar.DATE);
 }
}

In jsp

$('input.datepicker').datepicker(
{
    minDate : new Date(<%out.print(YourJavaClass.getServerDate());%>)
});

Upvotes: 1

Related Questions