How To Use Flash Message in CodeIgniter 4 ?

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Flash messages are generally used to display some information to end users. For example, let’s say we have a form. When we save data, delete data etc then after doing operation we have to show a confirmation message to users that operation has been done.

Inside this article we will see how to use flash message in CodeIgniter 4 application.

Note*: For this article, CodeIgniter v4.1 setup has been installed. May be when you are seeing, version will be updated. CodeIgniter 4.x still is in development mode.

Here we will see the step by step implementation of flash messages using session. Let’s get started.

Download & Install CodeIgniter 4 Setup

We need to download & install CodeIgniter 4 application setup to system.

To set application we have multiple options to proceed.

Here are the following ways to download and install CodeIgniter 4 –

  • Manual Download
  • Composer Installation
  • Clone Github repository of CodeIgniter 4

Complete introduction of CodeIgniter 4 basics – Click here to go. After going through this article you can easily download & install setup.

Here is the command to install via composer –

$ composer create-project codeigniter4/appstarter codeigniter-4

Assuming you have successfully installed application into your local system.

Turn Development Mode On

When we install CodeIgniter 4, we have env file at root. To use the environment variables means using variables at global scope we need to do env to .env

Open project in terminal

$ cp env .env

Above command will create a copy of env file to .env file. Now we are ready to use environment variables.

CodeIgniter starts up in production mode by default. Let’s do it in development mode. So that while working if we get any error then error will show up.

# CI_ENVIRONMENT = production

 // Do it to 
CI_ENVIRONMENT = development

Now application is in development mode.

Create Controller

Open project in terminal and type the command.

$ php spark make:controller Site

Site.php is the controller file which will be created inside /app/Controllers

Flash Message

To create flash messages, we have several option to initiate and display into view files.

Let’s see each step in detail.

Flash Message Settings

We will discuss each method to fire flash message and store data into it. Flash messages will be set inside controller methods.

Method #1

$session = session();

$session->setFlashdata("message", "This message is for end users #1");

$session->markAsFlashdata("message", "This message is for end users #1");

Method #2

session()->setFlashdata("message", "This message is for end users #2");

session()->markAsFlashdata("message", "This message is for end users #2");

Method #3

$_SESSION['message'] = 'This message is for end users #3';

So here, we have the following ways to store a flash message in their respective keys. Let’s see how can we access these over View files of CodeIgniter 4.

Render Flash Message To Views

To display a flash message again as above we have several ways.

Consider any of your view file of application. View files means the files from /app/Views folder.

Inside view file –

Method #1

<?= session("message") ?> or <?php echo session("message"); ?>

Method #2

<?= session()->getFlashdata("message") ?> or <?php echo session()->getFlashdata("message"); ?>

Method #3

Here, we are checking if message key exists or not.

         echo session("message");


         echo session("message");

We hope this article helped you to learn about How To Use Flash Message in CodeIgniter 4 Tutorial in a very detailed way.

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