Forem: Erland Muchasaj

Final and Readonly Classes in PHP

Erland Muchasaj — Tue, 21 Mar 2023 17:47:55 +0000

final classes

In the past, when you didn't want other classes to extend a certain class, you could mark it as final.

Consider the code below :



<?php

namespace App\Utils;

class ParentClass
{
    public function __construct(protected string $name) {
    }
}



<?php

namespace App\Utils;

class ChildClass extends ParentClass
{

}

So we have a ParentClass and a ChildClass that extends the parent.

we could use the ChildClass as following:



<?php

use App\Utils\ChildClass;

$obj = new ChildClass('Antonio');

var_dump($obj);

And this would output ChildClass public properties and also inherited properties from ParentClass as follows:

Now if we do not want our class to be extended we just put the word final at the beginning of the class as follows:



<?php

namespace App\Utils;

final class ParentClass
{
    public function __construct(
        protected string $name,
    ) {
    }
}

and calling the $obj = new ChildClass('Antonio'); again would result in: Class App\Utils\ChildClass cannot extend final class App\Utils\ParentClass.

So the definition of final in php is:

The final keyword is used to prevent a class from being inherited and to prevent inherited method from being overridden.

So if we declare class method as a final then that method cannot be override by the child class.
Same as method if we declare class as a final then that class cannot be extended any more.

readonly class

readonly classes are added on PHP 8.2.

finaland readonlyare two completely different concepts in PHP and have different implications when applied to a class.

As we saw earlier, making a class final means that it cannot be extended.



final class ParentClass{}

// Fatal error: Class ChildClass cannot extend final class ParentClass
class ChildClass extends ParentClass{}

In the other hand, making a class readonly means several things:

All instance properties of a class are implicitly marked as readonly, and cannot be reassigned.
Creation of dynamic properties is not allowed.
Only a readonly class can extend another readonly class.
readonly properties can be overridden

For example:



// PHP 8.2+
readonly class ParentClass
{
    public function __construct(
        public string $name
    ) {}
}

$obj = new ParentClass('Antonio');
echo 'Hello, My name is ' . $obj ->name; // "Hello, My name is Antonio"

If you try to re-assign a value to any object property after instantiation, it would throw the following error:



// PHP 8.2+
// Fatal error: Uncaught Error: Cannot modify readonly property ParentClass::$name
$obj ->name = 'Ndershkuesi';

This happens because all properties are implicitly readonly when you mark the class as readonly.

NOTE: readonly property cannot have default value.

final and readonly

You can also mark a class as both readonly and final as well, this means:

All class properties are implicitly readonly.
The class cannot be extended.

Example:



// PHP 8.2+
final readonly class ParentClass {
    public function __construct(
        public string $name
    ) {}
}

Usage:



$obj = new ParentClass('Antonio');
echo 'My name is ' . $obj->name; // "My name is Antonio"

And if you try to assign a value to any object property or if you try to extend the class then it would throw an error as follows:



// PHP 8.2+

// Fatal error: Uncaught Error: Cannot modify readonly property ParentClass::$name
$obj->name = 'Ndershkuesi';

// Fatal error: Class ChildClass cannot extend final class Shape
readonly class ChildClass extends ParentClass {}

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Upload files on Laravel 10

Erland Muchasaj — Tue, 07 Mar 2023 17:20:00 +0000

Uploading files is one common feature that most of the applications use, and yet is one of the things that I see many people struggling with.

Laravel offers a simple API to work with local filesystem as simple as:

Storage::putFileAs('images', $request->file('file'));

Often user needs to handle file validation, file size, dimensions, name, visibility, path, disk etc.

We will want to create a form that allows us to upload a file and submit it - and a route will accept this form, validate the input and handle the upload.

With this article, I will do a step-by-step file upload tutorial on Laravel 10 using erlandmuchasaj/laravel-file-uploader package.
In this Tutorial we will generate 2 routes.
One for creating a form where user will upload the file and another route for the file to be uploaded using the package.
We will create a simple form using Bootstrap Form UI components.

First things first, lets setup a brand new Laravel project.
Open the command-line tool and execute the following command to create a Laravel project from scratch.

composer create-project laravel/laravel --prefer-dist laravel-file-uploader

Then we go into the freshly created project directory:

cd laravel-file-uploader

Then we install the laravel-file-uploader package.

composer require erlandmuchasaj/laravel-file-uploader

After that we create a symbolic link to access the files that are going to be publicly accessible.
By default, the public disk uses the local driver and stores its files in storage/app/public.

To make these files accessible from the web, you should create a symbolic link from public/storage to storage/app/public.

To create the symbolic link, you may use the storage:link Artisan command:

php artisan storage:link

Create routes.

Go to route/web.php and create 2 additional routes. The first handles the form visualization and the other handles the form POST request.

use ErlandMuchasaj\LaravelFileUploader\FileUploader; // <= import the package
use Illuminate\Support\Facades\Route;
use Illuminate\Http\Request;


// visualize the form
Route::get('/files', function (Request $request) {
    return view('files');
})->name('files');

// handle the post request
Route::post('/files', function (Request $request) {

    $max_size = (int) ini_get('upload_max_filesize') * 1000;

    $extensions = implode(',', FileUploader::images());

    $request->validate([
        'file' => [
            'required',
            'file',
            'image',
            'mimes:' . $extensions,
            'max:'.$max_size,
        ]
    ]);

    $file = $request->file('file');

    $response = FileUploader::store($file);

    return redirect()
            ->back()
            ->with('success','File has been uploaded.')
            ->with('file', $response);
})->name('files.store');

Creating the blade files in Laravel.

In this step we create the view where the file uploader form will be placed.
Create a new file in resources/views/files.blade.php and place the following content:

<!DOCTYPE html>
<html lang="{{ str_replace('_', '-', app()->getLocale()) }}">
    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <title>File uploader</title>
        <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-rbsA2VBKQhggwzxH7pPCaAqO46MgnOM80zW1RWuH61DGLwZJEdK2Kadq2F9CUG65" crossorigin="anonymous">
    </head>
    <body class="antialiased">
        <div class="container">
            <div class="row">
                <div class="col-12">
                    @if ($message = Session::get('success'))
                        <div class="alert alert-success alert-dismissible fade show" role="alert">
                            <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
                            <strong>{{ $message }}</strong>
                        </div>
                    @endif
                    @if (count($errors) > 0)
                        <div class="alert alert-danger alert-dismissible fade show" role="alert">
                            <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
                            <ul class="mb-0 p-0">
                                @foreach ($errors->all() as $error)
                                    <li>{{ $error }}</li>
                                @endforeach
                            </ul>
                        </div>
                    @endif
                </div>
                <div class="col-12 py-5">
                    <div class="card my-5">
                        <div class="card-header">
                           <h3>Laravel File Uploader</h3>
                        </div>
                        <div class="card-body">
                            <form method="POST" action="{{ route('files.store')  }}" enctype="multipart/form-data">
                                @method('POST')
                                @csrf
                                <div class="mb-3">
                                    <label for="formFileLg" class="form-label">File input example</label>
                                    <input name="file" class="form-control form-control-lg" id="formFileLg"
                                           type="file">
                                </div>
                                <div class="mb-3">
                                    <button type="submit" value="submit" class="btn btn-primary">Upload</button>
                                </div>
                            </form>
                        </div>
                    </div>
                </div>
            </div>
        </div>
        <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-kenU1KFdBIe4zVF0s0G1M5b4hcpxyD9F7jL+jjXkk+Q2h455rYXK/7HAuoJl+0I4" crossorigin="anonymous"></script>
    </body>
</html>

This will show the form to the user to upload the files. The form in this view template is pointing to a route named files.store that we created earlier in routes/web.php file.

This is it for this tutorial.

If you need more information regarding the package used you can read more below:

erlandmuchasaj / laravel-file-uploader

A simple, yet powerful Laravel file uploader package

Laravel File Uploader

Laravel File Uploader offers an easy way to upload files to different disks The main purpose of the package is to remove the repeated and cumbersome code and simplify it into some simple methods.

Installation

You can install the package via composer:

composer require erlandmuchasaj/laravel-file-uploader

Usage

This package has an very easy and straight-forward usage Just import the package and pass the file as parameter, and it will handle the rest.

use ErlandMuchasaj\LaravelFileUploader\FileUploader
Route::post('/files', function (\Illuminate\Http\Request $request) {

    $max_size = (int) ini_get('upload_max_filesize') * 1000;
    
    // FileUploader::images() get all image extensions ex: jpg, png, jpeg, gif, etc.
    // FileUploader::documents() get all documents extensions ex: 'csv', 'html', 'pdf', 'doc', 'docx', 'ppt' etc.
    $extensions = implode(',', FileUploader::images());

    $request->

…

View on GitHub

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Let me know in the comment section below if you ever use this package in any of your projects.

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Thanks for reading.

PHP Sanitizer.

Erland Muchasaj — Tue, 07 Mar 2023 08:40:00 +0000

On the new year's eve, I set out to build some open source packages for PHP and Laravel community which is one of the best communities you can find. The packages would consist of libraries, utils, helpers and packages and also some starters for medium and large-scale projects.

I have been working with PHP and related technologies for over a decade now and more often than not, I find myself using the same peace of code in different projects.

Up until now I used to create Libraries which I would just transfer files from one project to another and reuse the library, but I wanted something more manageable and if I wanted to change something or fix issues to easily fix it in one place.

Backstory

In my early days in programming, I often had to create search pages using vanilla PHP.
This means I needed to get user input, parse it, sanitize it, and prepare for the query.
Another thing to consider was special characters for different languages for example:

э => e
Ë => e
Ç => c

For this reason I build a PHP Sanitizer class to only do just that. Sanitize user input and prepare it for SQL search queries.

erlandmuchasaj / sanitize

A package to sanitize your input.

PHP sanitize

This is a PHP package that helps to sanitize your input when performing search queries to DB It cleans the input from all malicious characters.

Installation

You can install the package via composer:

composer require erlandmuchasaj/sanitize

Usage

Sanitize library offers a sanitize method that takes a parameter a dirty string parameter and return a cleaned string.

use ErlandMuchasaj\Sanitize\Sanitize;

$dirtyString = 'Hello - World';

$sanitizedString = Sanitize::sanitize($dirtyString);

// do something with the sanitized text
// you can: $words = explode(' ', $sanitizedString);
// and search the DB per each word.

Support me

I invest a lot of time and resources into creating best in class open source packages.

If you found this package helpful you can show support by clicking on the following button below and donating some amount to help me work on…

View on GitHub

It is very simple to use. I will do a follow up with some examples of how to use it on your projects.

Let me know in the comment section below if you ever use it in any of your projects.
Don't forget to like and comment.
Follow me for more web development tips, new packages and more.
Thanks for reading.