Flashdata not getting cleared in Codeigniter - php

Question

I am using Codeigniter 2.1.4 and I have facing some issues with flashdata.
When I successfully submit record I can display the flashdata message. But if go to the other page from the page where flashdata message was displayed and then go back to previous page using browser back button it shows me flashdata message again.
How to clear flashdata message once it used?
I think its not the flashdata issue its cache problem. I am confused why this is happening. If its cache issue then how to remove it?
Below is code I have used,
//In the manage of controller
$this->session->set_flashdata('message', "Record updated successfully.");
// In the view of controller
$data['message'] = $this->session->flashdata('message');
// In the view page
echo $message;

Answer 1

Flash disappears only after next refresh

Answer 2

your code in controller is right
//In the manage of controller
$this->session->set_flashdata('message', "Record updated successfully.");
redirect('controller_name/function_name','refresh');
now in view use like this
if($this->session->flashdata('message')){echo $this->session->flashdata('message');}
hope it will work

Answer 3

Go to System->libries->Session->session.php
Find flshdata fuction and replace with this
public function flashdata($key = NULL)
{
if (isset($key))
{
$return= (isset($_SESSION['__ci_vars'], $_SESSION['__ci_vars'][$key], $_SESSION[$key]) && ! is_int($_SESSION['__ci_vars'][$key]))
? $_SESSION[$key]
: NULL;
unset($_SESSION[$key]);
return $return;
}
$flashdata = array();
if ( ! empty($_SESSION['__ci_vars']))
{
foreach ($_SESSION['__ci_vars'] as $key => &$value)
{
is_int($value) OR $flashdata[$key] = $_SESSION[$key];
}
}
unset($_SESSION[$key]);
return $flashdata;
}

Answer 4

You must redirect the page somewhere after $this->session->set_flash('item','value');
Example:
if ($this->form_validation->run() == FALSE){
$this->session->set_flashdata('error',validation_errors());
redirect(base_url().'user/login');
}
else{
$this->session->set_flashdata('success','Thank you');
redirect(base_url().'user/login');
}
Usually developer make a mistake when they submit data to same page. They set flash data but forget to redirect.

Answer 5

if you want to clear set_flash in controller or another view file, then you can use this simple code.
$this->session->set_flashdata('error', 'User not found...'); //create set_flash
destroy set_flash
//echo "<pre>"; print_r($_SESSION); die; //for check
if(isset($_SESSION['error'])){
unset($_SESSION['error']);
}

Answer 6

$this->session->set_flashdata('message', "Record updated successfully.");
After setting the flashdata redirect to some function or to the same function.

Answer 7

If you refresh in the same controller function the flashdata won't be deleted.Also going back and forth in the browser does't affect the flashdata.
to clear the flashdata redirect to another controller function and it will work.

Answer 8

As Code igniter does not offer the possibility to destroy the flashdata, you can work around this problem with a second fictitious call of the flashdata function without echo :
if ($this->session->flashdata('message')) :
echo $this->session->flashdata('message'); // First normal call
$this->session->flashdata('message'); // Second fictitious call
endif;

Answer 9

Looks like this will be fixed in 3.1.12: https://github.com/bcit-ci/CodeIgniter/pull/6013

Answer 10

It is php version issue. you need to modify your session file.
go to your Session.php file
find the _ci_init_vars function and add this "$value === 'old' ||" in the elseif condition.
or replace the function with following.
protected function _ci_init_vars()
{
if ( ! empty($_SESSION['__ci_vars']))
{
$current_time = time();
foreach ($_SESSION['__ci_vars'] as $key => &$value)
{
if ($value === 'new')
{
$_SESSION['__ci_vars'][$key] = 'old';
}
// Hacky, but 'old' will (implicitly) always be less than time() ;)
// DO NOT move this above the 'new' check!
elseif ($value === 'old' || $value < $current_time)
{
unset($_SESSION[$key], $_SESSION['__ci_vars'][$key]);
}
}
if (empty($_SESSION['__ci_vars']))
{
unset($_SESSION['__ci_vars']);
}
}
$this->userdata =& $_SESSION;
}

Answer 11

I have faced same problem when I have update php version 7 to php 8.
You can manually unset flash data just after display your error or success message.
$this->session->unset_userdata('err_msg')

Answer 12

it's work : https://github.com/bcit-ci/CodeIgniter/pull/6013#issuecomment-1316482414
This is an issue in newer version of php . You can fix it by replacing line 420 in system/libraries/Session/Session.php:
elseif ($value < $current_time)
with
elseif ($value === 'old' || $value < $current_time)
thanks,