An HTTP cookie is a piece of data stored by the user's web browser. Unless otherwise specified, cookies can be created, read, modified and deleted both by JavaScript and from server-side through HTTP headers.

An HTTP cookie is a piece of data stored by the user's web browser. Unless otherwise specified, cookies can be created, read, modified and deleted both by JavaScript and by server-side through HTTP headers.

Cookies can be used to remember the state of the session, such as authentication, state of GUI controls and personalization through user preferences. They can also be inappropriately used to track the browsing history and to transfer malware.

Using cookies in Joomla extensions

// Get input cookie object
$inputCookie  = JFactory::getApplication()->input->cookie;

// Get cookie data
$value        = $inputCookie->get($name = 'myCookie', $defaultValue = null);

// Check that cookie exists
$cookieExists = ($value === null);

// Set cookie data
$inputCookie->set($name = 'myCookie', $value = '123', $expire = 0);

// Remove cookie
$inputCookie->set('myCookie', null, time() - 1);

Some rules about $expire value

  • its a Unix tinestamp in seconds, like return value of time().
  • $expire == 0: cookie lifetime is of browser session.
  • $expire < time(): cookie is being deleted (expire set to past). You could remove cookie by setting it's value to null, but apparently IE fails to do so.

Notes

Keep in mind that cookies should be set before headers are sent (usually before output is echoed).

Cookie key and value should be properly escaped

Non-string values

When serializing the value on set (like json_encode($dataNode)), remember to use proper filter to retrieve it later on. Default is cmd, which filters out pretty much anything but a-Z, 0-9 and cracks JSON structure.

// Get cookie data
$encodedString = $inputCookie->get('myCookie', null, $filter = 'string');

// Decode
$values = json_decode($encodedString);

// Encode and Set
$inputCookie->set('myCookie', json_encode($values));

Rererences

Source:

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