View Cells in CodeIgniter 4 Tutorial with Example

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View Cells allow us to insert HTML that is generated outside of controller. It simply calls the specified class and method, which must return a string of valid HTML.

Inside this article we will see the complete concept to use View Cells in CodeIgniter 4. It will be an interesting article to learn.

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Let’s get started.


CodeIgniter 4 Installation

To create a CodeIgniter 4 setup run this given command into your shell or terminal. Please make sure composer should be installed.

composer create-project codeigniter4/appstarter codeigniter-4

Assuming you have successfully installed application into your local system.


Environment (.env) Setup

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

Either we can do via renaming file as simple as that. Also we can do by terminal command.

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.

Enable Development Mode

CodeIgniter starts up in production mode by default. You need to make it in development mode to see any error if you are working with application.

Open .env file from root.

# CI_ENVIRONMENT = production

 // Do it to 
 
CI_ENVIRONMENT = development

Now application is in development mode.


Create Database

To create a database, either we can create via Manual tool of PhpMyadmin or by means of a mysql command.

We will use MySQL command to create database. Run this command into Sql tab of PhpMyAdmin.

CREATE DATABASE codeigniter4_app;

Successfully, we have created a database.


Database Connection

Open .env file from project root.

Search for DATABASE. You should see the connection environment variables into it. Put your updated details of database connection string values.

 
#--------------------------------------------------------------------
# DATABASE
#--------------------------------------------------------------------

database.default.hostname = localhost
database.default.database = codeigniter4_app
database.default.username = admin
database.default.password = admin
database.default.DBDriver = MySQLi
database.default.DBPrefix =
database.default.port = 3306
  

Now, database successfully connected with the application.


Create Migration

Open project into terminal and run this spark command.

$ php spark make:migration CreateBooks

It has generated a file with name 2021-02-09-120132_CreateBooks.php at /app/Database/Migrations folder.

Open up the file and write this code into it.

<?php

namespace App\Database\Migrations;

use CodeIgniter\Database\Migration;

class CreateBooks extends Migration
{
	public function up()
	{
		$this->forge->addField([
            'id' => [
                'type' => 'INT',
                'constraint' => 5,
                'unsigned' => true,
                'auto_increment' => true,
            ],
            'name' => [
                'type' => 'VARCHAR',
                'constraint' => '100',
                'null' => false
            ],
            'author' => [
                'type' => 'VARCHAR',
                'constraint' => '100',
                'null' => false,
            ],
            'cost' => [
                'type' => 'INT',
                'constraint' => 100,
                'null' => false,
            ],
        'created_at datetime default current_timestamp',
        ]);
        $this->forge->addPrimaryKey('id');
        $this->forge->createTable('books');
	}

	public function down()
	{
		$this->forge->dropTable('books');
	}
}

Next, we need to migrate this created migration into database.

$ php spark migrate

It will create a database table with name “books”.


Create Seeder

Back to terminal and run this spark command.

$ php spark make:seeder BookSeeder

It has generated a file with name BookSeeder.php at /app/Database/Seeds folder.

Open up the file and write this code into it.

<?php

namespace App\Database\Seeds;

use CodeIgniter\Database\Seeder;
use Faker\Factory;

class BookSeeder extends Seeder
{
	public function run()
    {
        for ($i = 0; $i < 10; $i++) { //to add 10 books. Change limit as desired
            $this->db->table('books')->insert($this->generateBooks());
        }
    }

    private function generateBooks(): array
    {
        $faker = Factory::create();
        return [
            'name' => $faker->name(),
            'author' => $faker->name(),
            'cost' => random_int(300, 800)
        ];
    }
}

Next, we need to seed test data into table

$ php spark db:seed BookSeeder

It will generate and insert 10 rows of fake data into “books” table.


Add Route

Open Routes.php file from /app/Config folder.

Add this route into it.

//...

$routes->get("list-data", "Site::listdata");

//...

Create Model

Back to terminal and run this spark command.

$ php spark make:model Book

It has generated a file with name Book.php at /app/Models folder.

Open up the file and write this code into it.

<?php

namespace App\Models;

use CodeIgniter\Model;

class Book extends Model
{
	protected $DBGroup              = 'default';
	protected $table                = 'books';
	protected $primaryKey           = 'id';
	protected $useAutoIncrement     = true;
	protected $insertID             = 0;
	protected $returnType           = 'array';
	protected $useSoftDelete        = false;
	protected $protectFields        = true;
	protected $allowedFields        = [];

	// Dates
	protected $useTimestamps        = false;
	protected $dateFormat           = 'datetime';
	protected $createdField         = 'created_at';
	protected $updatedField         = 'updated_at';
	protected $deletedField         = 'deleted_at';

	// Validation
	protected $validationRules      = [];
	protected $validationMessages   = [];
	protected $skipValidation       = false;
	protected $cleanValidationRules = true;

	// Callbacks
	protected $allowCallbacks       = true;
	protected $beforeInsert         = [];
	protected $afterInsert          = [];
	protected $beforeUpdate         = [];
	protected $afterUpdate          = [];
	protected $beforeFind           = [];
	protected $afterFind            = [];
	protected $beforeDelete         = [];
	protected $afterDelete          = [];
}

Create Controller

Back to terminal and run this spark command.

$ php spark make:controller Site

It has generated a file with name Site.php at /app/Controllers folder.

Open up the file and write this code into it.

<?php

namespace App\Controllers;

use App\Models\Book; // Loading model

class Site extends BaseController
{
    public function listdata()
    {
        $book_obj = new Book();

        $books = $book_obj->findAll();

        return view("books"); // Calling view file
    }
}

Create Library

Create a file with name BooksLibrary.php inside /app/Libraries. Add this piece of code into it.

<?php

namespace App\Libraries;

use App\Models\Book;

class BooksLibrary{

    public function loadBooks(){

        $book_obj = new Book();

        $books = $book_obj->findAll();

        return view("partials/books-template", [
            "books" => $books
        ]);
    }
}

Inside this library we have written code for followings –

  • Fetch all books from database table
  • Send to view file
  • Return a HTML view from method with table data

Create Template Files & View Cell guide

Create a folder with name “partials” into /app/Views. Inside this folder, Create a partial file books-template.php. This file contains a section of code, say list of books for this example.

Open books-template.php file and write code.

<table class="table">
    <thead>
      <tr>
        <th>ID</th>
        <th>Name</th>
        <th>Author</th>
        <th>Cost</th>
      </tr>
    </thead>
    <tbody>
    <?php
      
      if(count($books) > 0){

        foreach($books as $book){
            ?>
            <tr>
                <td><?= $book['id'] ?></td>
                <td><?= $book['name'] ?></td>
                <td><?= $book['author'] ?></td>
                <td><?= $book['cost'] ?></td>
            </tr>
            <?php
        }
      }
    ?>
    </tbody>
</table>

Create another view file books.php at /app/Views

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Books List</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"></script>
</head>
<body>

<div class="container">

  <h2>Books Table</h2>

  <?= view_cell("\App\Libraries\BooksLibrary::loadBooks") ?>  
  
</div>

</body>
</html>

View cells are used to return partial templates with dynamic data. Here, we can see we have used view_cell() which returns HTML view with dynamic data.

\App\Libraries\BooksLibrary::loadBooks returns HTML view with books data.

Passing parameters to View Cells

# While Calling view

<?= view_cell("\App\Libraries\BooksLibrary::loadBooks", ["category" => "Science"]) ?>
  
# At Library  
public function loadBooks(array $params = [])
{
    // ... Other code
    return view('<template>', ['category' => $params['category']]);
}

View Cell Caching

# View cell caching for 60 seconds

<?= view_cell("\App\Libraries\BooksLibrary::loadBooks", ["category" => "Science"], 60) ?>

Application Testing

Open project into terminal and start development server.

$ php spark serve

URL: http://localhost:8080/list-data

We hope this article helped you to learn View Cells in CodeIgniter 4 Tutorial in a very detailed way.

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