Flashdata not getting cleared in Codeigniter

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;

Effrontery

I've read your comments on both answers, and yes you are right using back button is "never" going to give you NEW data. Please after every form submit and processing form/data redirect() somewhere so you (mostly your users) wont have to deal with "Do you want to resend data?" nag that Chrome/Firefox provides. – Broad

When I use header("Expires: Thu, 19 Nov 1981 08:52:00 GMT"); header("Cache-Control: no-store, no-cache, must-revalidate"); in index.php it works fine. Is this good option for removing caching issue? – Effrontery

I would go for "refresh" ( redirect() ) not for screwing around with headers. But you solved your problem, we do not have the big picture as you have (why is there a need for back button to work - redirect() solves this "issue"). – Broad

@Sachin, Did you ever found solution to this? I have spent hours but to no avail – Helvetian

Answer 1

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,

Quarrelsome

Pretty funny, the source code comments know they took a dumb shortcut for no reason: // Hacky, but 'old' will (implicitly) always be less than time() ;) The winky face really just... – Viguerie

Answer 2

Flash disappears only after next refresh

Affricative

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;
}

Sublunar

If this answer is still relevant to this 7 year old question, could you give a little bit more detail as to how this is fixing this problem. Only a block of code as a solution might be a fix, but it's not helping people learn. – Afrit

Ok. What I did is each session key that is requested I reset the value – Sublunar

Answer 4

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

Spalding

Thanks, I am sure that the issue is not of flashdata its a cache issue. Because when I click browser back button it displaying again. – Effrontery

tell me one thing after setting flashdata are you redireting to any function or using $this->load->view function. – Spalding

Yes, I am redirecting page to view funtion – Effrontery

if you use redirect() function then second time flashdata will not show value again. – Spalding

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']);
}

Minutiae

I have a doubt here, I mostly set the flashdata in an AJAX and at success of the AJAX, I just reload the page. It shouldn't be done, right ? – Abelmosk

Answer 6

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;
}

Homozygous

Answer 7

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.

Micrometeorology

Answer 8

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

Abreaction

Answer 9

$this->session->set_flashdata('message', "Record updated successfully.");

After setting the flashdata redirect to some function or to the same function.

Arnoldarnoldo

Thanks, I am sure that the issue is not of flashdata its a cache issue. Because when I click browser back button it displaying again. – Effrontery

Answer 10

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.

Rhiamon

Answer 11

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;

Sinuate

Answer 12

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')

Bodkin