codeigniter_tutorial

15. Tempdata
CodeIgniter
In some situations, where you want to remove data stored in session after some specific
time-period, this can be done using tempdata functionality in CodeIgniter.
Add Tempdata
To add data as tempdata, we have to use mark_as_tempdata() function. This
function takes two argument items or items to be stored as tempdata and the
expiration time for those items are as shown below.
// 'item' will be erased after 300 seconds(5 minutes)
$this->session->mark_as_temp('item',300);
You can also pass an array to store multiple data. All the items stored below will be
expired after 300 seconds.
$this->session->mark_as_temp(array('item','item2'),300);
You can also set different expiration time for each item as shown below.
// 'item' will be erased after 300 seconds, while 'item2'
// will do so after only 240 seconds
$this->session->mark_as_temp(array(
'item'=>300,
'item2'=>240
));
Retrieve Tempdata
We can retrieve the tempdata using tempdata() function. This function assures that
you are getting only tempdata and not any other data. Look at the example given below
to see how to retrieve tempdata. tempdata() function will take one argument of the
item to be fetched.
$this->session->tempdata('item');
If you omit the argument, then you can retrieve all the existing tempdata.
Remove Tempdata
Tempdata is removed automatically after its expiration time but if you want to remove
tempdata before that, then you can do as shown below using the unset_tempdata()
function, which takes one argument of the item to be removed.
$this->session->unset_tempdata('item');
61