From Symfony to Django

Lately I’ve been playing with Django (in a real project, not tutorials) and all I have to say is… Oh My God!! I’m so impressed with Django’s clarity, speed of development and “cleanliness”, that I’m even planning for it to become my main ‘go-to’ framework! Don’t get me wrong, I’ve been working with Symfony for a few years and it’s still going to be the main framework I use for PHP projects, and probably the most comfortable I’ll feel working with for a while, but right now Django is like a new toy and I’m really excited to share this with you!

Furthermore, Django seems to perform far better in performance tests (less CPU resources, faster response…) than Symfony. Check here for more info on this.

This blog post is not a ‘Django getting started guide’, there’s plenty of those online already. Please visit Django’s oficial page for more info on this.

This blog post is for Symfony developers who wish to try Django out and are unaware of the Django project structure, file structure, etc. I’m going to go through the basics so you get a feel of what it’s like to code in Django and hopefully you feel comfortable enough to give it a go 🙂

Routing

Routing files are the ones which have mapped the routes for our application. Symfony and Django alike will try to match one of these routes to handle it.

Symfony annotations in controller

use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;

/**
 * Displays a form to edit an existing customer entity.
 *
 * @Route("/{id}/edit", name="app_customer_edit")
 */

Symfony YAML: routing.yml

app_customer_edit:
    path:     /{id}/edit
    defaults: { _controller: AppBundle:Customer:edit }

In Symfony you can include specific routing of a bundle like so:

app:
    resource:   "@AppBundle/Resources/config/routing.yml"
    prefix:     /

Django: urls.py

Django routing in a config file called urls.py

from app.views import customer

urlpatterns = [
    url(r'^(?P\d+)/edit$', customer.update_customer, name='customer_edit'),
]

You can also include specific routing in Django

urlpatterns = [
    url(r'^customer/', include('app.urls.customer')),
]

Controllers

Once matched a certain route, Controllers are the ones that receive the request and return a response, with whatever logic you may need in between, using services and so on.

Symfony: CustomerController.php

A Controller in Symfony, which has the action that will fire if the route matches

/**
 * Customer controller.
 *
 * @Route("customer")
 */
class CustomerController extends CoreController
{

    /**
     * Displays a form to edit an existing customer entity.
     *
     * @Route("/{id}/edit", name="app_customer_edit")
     */
    public function editAction(Request $request, Customer $customer)
    {
    
        //custom logic
    
        return $this->render('AppBundle:Customer:edit.html.twig', array(
                'param1' => $param1,
                //...
            ));
    }

}

Django: views.py

In Django, the Controller is called View, so the views.py will have the function we specified in the urls.py

def update_customer(request, pk):

    //custom logic

    return render(request, 'customer/edit.html', {
        'param1': param1,
    })

Template rendering

The templating engine is very very similar, so you won’t have any trouble adapting to the new one.

Symfony: edit.html.twig

Twig is the template engine in Symfony. The Resources/views folder in Symfony which contains all the twigs.

For instance, to create an anchor for a Symfony route in twig:

< a href="{{ path('app_customer_edit', { 'id': customer.id }) }}"> Edit the customer < /a>

Django: edit.html

Django uses it’s own templating engine, and the folder containing all the html files is called templates. Code looks very similar.

< a href="{% url "customer_edit" customer.id %}"> Edit the Customer < /a>

Static files

Symfony: public/

The Resources/public folder in Symfony which contains all the js/css files for later deployment.

To load some of those files in the template in Twig

< link rel="stylesheet" href="{{ asset('bundles/app/vendor/bootstrap/css/bootstrap.min.css') }}">
< script type="text/javascript" src="{{ asset('bundles/app/vendor/bootstrap/js/bootstrap.min.js') }}">

Django: static/

In Django, these files are gathered in a folder called static.

{% load static %}

< link rel="stylesheet" href="{% static "vendor/bootstrap/dist/css/bootstrap.min.css" %}">
< script src="{% static "vendor/bootstrap/dist/js/bootstrap.min.js" %}">

Entities

Entities are mapped models that translate into database tables. The idea is to abstract the database completely, so you can either use Mysql, Mongo, PostgreSql,… totally independent from the code.

Symfony: Customer.php

Using Doctrine, the Customer entity under the Entity folder in Symfony would look something like this:

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity()
 * @ORM\Table(name="app_customer")
 */
class Customer
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @var string
     *
     * @ORM\Column(name="name", type="string", length=50, nullable=true)
     */
    protected $name;

    /**
     * @var string
     *
     * @ORM\Column(name="surname", type="string", length=80, nullable=true)
     */
    protected $surname;

    /**
     * @var Address
     *
     * @ORM\OneToOne(targetEntity="Address", cascade={"persist"})
     * @ORM\JoinColumn(nullable=true)
     */
    protected $address;


    //more attributes...


	/**
     * @return string
     */
    public function __toString()
    {
        return trim((string) $this->getName(). ' '.  $this->getSurname());
    }
    
    /**
     * Get id
     *
     * @return integer
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Set name
     *
     * @param string $name
     *
     * @return Customer
     */
    public function setName($name)
    {
        $this->name = $name;

        return $this;
    }

    /**
     * Get name
     *
     * @return string
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Set surname
     *
     * @param string $surname
     *
     * @return Customer
     */
    public function setSurname($surname)
    {
        $this->surname = $surname;

        return $this;
    }

    /**
     * Get surname
     *
     * @return string
     */
    public function getSurname()
    {
        return $this->surname;
    }

    /**
     * Set address
     *
     * @param \AppBundle\Entity\Address $address
     *
     * @return Customer
     */
    public function setAddress(\AppBundle\Entity\Address $address = null)
    {
        $this->address = $address;

        return $this;
    }

    /**
     * Get address
     *
     * @return \AppBundle\Entity\Address
     */
    public function getAddress()
    {
        return $this->address;
    }

    //more getters and setters...

Django: models.py

In Django, much slimmer. No need of any getters and setters, as it has it’s own model API that handles that.

from django.db import models
from app.models.address import Address


class Customer(models.Model):
    name = models.CharField('Name', max_length=50)
    surnames = models.CharField('Surnames', max_length=80)
    address = models.OneToOneField(
        Address,
        on_delete=models.CASCADE
    )

    def __str__(self):
    	return self.name + ' ' + self.surnames

Forms

Symfony: FormType.php

In Symfony we’ll use a FormType, which usually extends from AbstractType. We also need to tell Symfony what class it’s mapping through the configureOptions method.

use Symfony\Component\Form\AbstractType;

class CustomerType extends AbstractType
{
    /**
     * {@inheritdoc}
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('name', null, [
                'label' => 'Nom',
            ])
            ->add('items', CollectionType::class, [
                'entry_type' => CustomerItemType::class,
                'allow_add'    => true,
                'allow_delete' => true,
                'by_reference' => false
            ])
            ...
         ;
    }

    /**
     * {@inheritdoc}
     */
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => Customer::class,
            'cascade_validation' => true,
        ));
    }

    /**
     * {@inheritdoc}
     */
    public function getBlockPrefix()
    {
        return 'appbundle_customer';
    }
}

To build the form from the controller we would use something like this

$form = $this->createForm(CustomerType::class, $customer);

This basically calls the form builder service and builds an CustomerType form with the $customer instance.

Django: forms.py

In Django it’s much simpler! We also need to tell Django what model class it’s mapping through the Meta assignment.

from django import forms

class CustomerForm(forms.ModelForm):

    class Meta:
        model = Customer
        exclude = ('',)

To build the form from the view we would use something like this

form_customer = CustomerForm(request.POST, instance=customer_inst)

Same as Symfony, this will create the form with the customer_inst instance.

ORM – Object Relational Manager

The ORM allows us to access objects from the database in a ‘object manner’, so we don’t need to worry how to access that DDBB, it’s totally independent.

Symfony: Doctrine

In Symfony we use Doctrine, so let’s find an Customer given a request id

public function editAction(Request $request)
{
	$em = $this->getDoctrine()->getManager();
	$customer = $em->getRepository('AppBundle:Customer')->find($request->get('id'));
	$customers = $em->getRepository('AppBundle:Customer')->findAll();
	$address = $customer->getAddress();

	// Find an customer depending on a address
	$customerInst = $em->getRepository('AppBundle:Customer')->findOneByAddress($addressInst);
}

Django: API

In Django it uses it’s own API.

def update_customer(request, pk):
    customer = Customer.objects.get(pk=your_object_id)
    customers = Customer.objects.all()
    address = customer.address

    # Find an customer depending on a address
    customer_inst = Customer.objects.get(address=address_inst)

Summary

I’m not saying Django is better than Symfony or the other way round. Each and every framework/technology has it’s place, and as developers, I believe we should be open minded and have as many tools as possible under the belt. So I strongly recommend every Symfony dev to try Django out if you haven’t done yet. I assure you that you’ll love everything about it, even the great admin it gives you out of the box 🙂

The new era of micro frameworks, welcome Symfony 4

Whoop Whoop! Symfony 3.4 and Symfony 4 were released a couple days ago with lots of hype around it!

But what is really different this time from other Symfony versions? Let’s have a look…

Decoupling components

First off, conceptually, Symfony framework is moving towards a more decoupled structure. You probably noticed that instead of creating a new project through the symfony installer, you now use the following command.

composer create-project symfony/skeleton your-project-name

 
The reason behind this is that in earlier versions, when creating a symfony project, you were installing lots of dependencies and components that you may or may not be using in your application.

The idea now is creating a skeleton type project, and then installing all the components we need for that project seperately. This allows the programer complete freedom to be using whatever component he or she needs.

This in turn means that each Symfony application you code might use different components, even if they were created by Symfony, and therefore you do not need to install all of them every time, which makes each project more light weight!

For example, an API project might not use Twig, so there’s no need to install it in the vendor directory right?

Or I might just install the command component because I need to write some php scripts and I need a quick wrapper to organise my code.

Neither of the projects above would need twig, or form, or entities, or orm… you get the point.

I still remember the days when you had one big bloated Symfony framework installed, and many apps inside it. Inside each app, there were bundles.

After that, it evolved into one app per symfony installation, and each app had it’s different bundles.

It’s now time for the bundle less symfony. Best practices now say that you should have one skeleton per project, and following the decoupling of components, each project will have just the component it needs. This is just great, because every project will now have the underlying code that is really necessary, and not a bloated version of all the Symfony components together.

Having said this, there’s a few components I use 99% of the time when creating websites, so I created this small wrapper script so it’s easy for me to get them all, feel free to grab it and add/remove at your taste :). I call it ‘symfony-create-project.sh’

#!/bin/bash
# This script is a wrapper for creating a skeleton and installing the basic components I use most of the time
# To use it: bash symfony-create-project name-of-your-project

if [ "$1" != "" ]; then
	composer create-project symfony/skeleton "$1"
	cd "$1"
	composer require annotations
	composer require --dev profiler
	composer require twig
	composer require orm
	composer require form
	composer require form validator
else
	echo "parameter expected: name-of-your-project"
fi

Directory Structure

First thing you notice is the disappearance of the web folder. You now have the public folder instead. Inside it we can also see that app.php and app_dev.php have disappeared. Instead, we now have a more default index.php. The environment will be controlled by a .env file in the root directory of the project.

Second of all, the whole Resources folder inside src/ has disapeard as well, and all of it’s contents are in different places. The config files (routing.yml, services.yml…) are in the config/ folder in the root directory. This makes sense now since we have bundle-less applications. All of the twig files have also moved to a general templates/ folder in the root directory.

Now the src/ folder is just for php code, which makes much more sense if you work on a team with frontend and backend dev’s, each of them can now focus on their own folder.

Autoconfiguring and Autowiring

This is my absolute favourite.

Let me just copy this with the comments, as it explains everything really well.

services:
    # default configuration for services in *this* file
    _defaults:
        autowire: true      # Automatically injects dependencies in your services.
        autoconfigure: true # Automatically registers your services as commands, event subscribers, etc.
        public: false       # Allows optimizing the container by removing unused services; this also means
                            # fetching services directly from the container via $container->get() won't work.
                            # The best practice is to be explicit about your dependencies anyway.

Let’s dive into the code.

So I created a new service class,

<?php

namespace App\Utils;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\Routing\Annotation\Route;

class NumberGenerator
{
    public function __construct()
    {
    }

    public function getRandomNumber()
    {
        return  mt_rand(0, 100);
    }
}

Injected into the action,

<?php

namespace App\Controller;

use App\Utils\NumberGenerator;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\Routing\Annotation\Route;

class DefaultController extends Controller
{
    /**
     * @Route("/default/home")
     */
    public function home(NumberGenerator $numberGenerator)
    {
        return $this->render('default/home.html.twig', array(
            'number' => $numberGenerator->getRandomNumber(),
        ));
    }
}

and BANG, it worked like expected.

Let’s recapitulate here… before, we had to create the service, add it in the dependency injection config file, and then get it from the container.

What we just did in Symfony4 is create the service and inject it in the action we needed it. No configuration, no getting… just injection. This REALLY speeds up the process, enough configuration and more coding!!

However, if you don’t want to inject your service in the action, you can still use the container with the get function as we did in the past, although best practices advise not to.

Firstly,


composer require dependency-injection

Secondly, we need to set the service to public.

services:

    App\Utils\NumberGenerator:
        public: true

You can now get the service from the container

...
return $this->render('default/home.html.twig', array(
            'number' => $this->get(NumberGenerator::class)->getRandomNumber(),
        ));
...

There’s another component/bundle, which although is not super necessary, makes your life much much easier: Yup, you guessed it, it’s the Maker Bundle

composer require maker-bundle

This components creates the skeleton files for you (controllers, entities, forms,… etc), for example

bin/console make:controller CarController

More info on the maker bundle here.
More info on all the different component recipes here.

Conclusion

I just love how Symfony keeps giving more and more control to the developer.

Lots uf us (me included) know that changing and evolving things that we’re used to doing is sometimes painful… but after playing with it a little bit, I see this upgrade as a great step forward for better code, better standards and better readability.

So thank you to the Symfony team and everyone who contributed for making this happen!

Happy coding!!