To implement Symfony forms with children forms (form collections) to add or remove elements, we'll create a simple Book entity related to a Author entity in a one-to-many relationship. We'll use form collections to allow users to add, update or remove authors while creating or editing a book.

 

Create the Entity Classes:
Create the Book and Author entity classes and set up the one-to-many relationship between them.

// src/Entity/Book.php
namespace App\Entity;

use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 */
class Book
{
    // ... other properties and annotations ...

    /**
     * @ORM\OneToMany(targetEntity="Author", mappedBy="book", cascade={"persist", "remove"}, orphanRemoval=true)
     */
    private $authors;

    public function __construct()
    {
        $this->authors = new ArrayCollection();
    }

    // ... getters and setters ...
}

// src/Entity/Author.php
namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 */
class Author
{
    // ... other properties and annotations ...

    /**
     * @ORM\ManyToOne(targetEntity="Book", inversedBy="authors")
     * @ORM\JoinColumn(name="book_id", referencedColumnName="id")
     */
    private $book;

    // ... getters and setters ...
}

 

Create the Form Type Classes:
Now, create the form type classes for the Book and Author entities. In the BookType class, use the CollectionType field type to handle the one-to-many relationship with AuthorType as the embedded child form.

It is a very common use case to upload a file along with other input data when dealing with Symfony forms. When you have a form that involves a one to many or many to many relationships, you may follow this example:

 

Prerequisites:

 

To allow users to upload a files in the previous example, we'll modify the AuthorType form to include a FileType field that will enable the uploading of files associated with each author. Additionally, we'll update the BookType form to enable file uploads for each author. Let's assume we want to add a file upload field for the "avatar" of each author.

 

Update the Author Entity:

Add a new property to the "Author" entity to store the avatar image filename.

// src/Entity/Author.php
namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 */
class Author
{
    // ... other properties and annotations ...

    /**
     * @ORM\Column(type="string", nullable=true)
     */
    private $avatarFilename;

    // ... getters and setters ...
}

 

Update the AuthorType Form:
Update the "AuthorType" form to include a FileType field for the avatar upload.

To implement pub-sub with RabbitMQ in Symfony, you may follow these steps:

 

Set up RabbitMQ:

Install RabbitMQ on your system or use a hosted RabbitMQ service.
Make sure you have the necessary credentials (username, password) to connect to RabbitMQ.


Install RabbitMQ Bundle:

In your Symfony project, use the RabbitMQ Bundle to integrate RabbitMQ easily. Install the bundle using Composer:

composer require enqueue/amqp-bundle

 

Configuration:
Configure the RabbitMQ connection in the config/packages/enqueue.yaml file:

enqueue:
    transport:
        default: 'amqp://guest:guest@localhost/%2f' # Replace with your RabbitMQ connection details

To interact with Elasticsearch from a service class using Symfony, you'll need to use the Elasticsearch PHP client, which provides a convenient way to perform CRUD operations on the Elasticsearch cluster. Here's an example of how you can achieve this:

 

Install the Elasticsearch PHP client via Composer:

composer require elasticsearch/elasticsearch

 

Create the Symfony service class that will interact with Elasticsearch:
Assuming you have a Symfony project set up, create a new service class (e.g., ElasticsearchService) under the src/Services directory: