Fetching client time using JavaScript and comparing them with values stored in the database

Question

I am developing a module, where:

1. The administrator enters time in (0-23) format.These values gets saved in database.
2. In the front end (for the website users) I need to fetch the current client time (not the server time), maybe using JavaScript, and then comparing it with the stored time (in PHP variables with current time fetched using JavaScript).

I want to do something like the following.

// $time_one: from the database.
// $time_two: from the database.
// $currentTime:  client current time.

if (currentTime > $time_one && currentTime < $time_two) {
  // Display some message.
}

How can this be done? Can PHP and JavaScript be mixed in the module file?

Answer 1

You can pass values from PHP to JavaScript using code similar to the following one.

drupal_add_js(
  array('myModule' => array('time_one' => $time_one, 'time_two' => $time_two)),
  'setting'
);

$time_one and $time_two are the PHP variables that contain the values you fetch from the database.

JavaScript would access those values using the following code.

time_one = Drupal.settings.myModule.time_one;
time_two = Drupal.settings.myModule.time_two;

Answer 2

Send server time to the client side via js variables: drupal_add_js, see example.