Schema

This library can parse a TypeSchema specification either from a JSON file or from PHP classes using reflection and attributes. Based on this schema it can generate source code and transform raw JSON data into DTO objects. Through this you can work with fully typed objects in your API for incoming and outgoing data. It provides basically the following features:

• Transform raw JSON data into DTO objects
• Generate source code based on a schema (i.e. PHP, Typescript)
• Validate data according to the provided schema

Usage

At first, we need to describe our data format with a TypeSchema specification. Then we can generate based on this specification the fitting PHP classes.

{
  "definitions": {
    "Person": {
      "type": "object",
      "properties": {
        "firstName": {
          "type": "string"
        },
        "lastName": {
          "type": "string"
        },
        "age": {
          "description": "Age in years",
          "type": "integer",
          "minimum": 0
        }
      },
      "required": [
        "firstName",
        "lastName"
      ]
    }
  },
  "$ref": "Person"
}

To generate the PHP classes we use the following command:

vendor/bin/schema schema:parse --format=php schema.json

Note you can also skip this step and directly write the PHP class by your self. The advantage of starting with a JSON representation is that you have defined your models in a neutral format so that you can generate the models for different environments i.e. also for the frontend using the TypeScript generator. The command generates the following source code:

<?php

declare(strict_types = 1);

#[Required(["firstName", "lastName"])]
class Person implements \JsonSerializable
{
    protected ?string $firstName = null;
    protected ?string $lastName = null;
    #[Description("Age in years")]
    #[Minimum(0)]
    protected ?int $age = null;
    public function setFirstName(?string $firstName) : void
    {
        $this->firstName = $firstName;
    }
    public function getFirstName() : ?string
    {
        return $this->firstName;
    }
    public function setLastName(?string $lastName) : void
    {
        $this->lastName = $lastName;
    }
    public function getLastName() : ?string
    {
        return $this->lastName;
    }
    public function setAge(?int $age) : void
    {
        $this->age = $age;
    }
    public function getAge() : ?int
    {
        return $this->age;
    }
    public function jsonSerialize()
    {
        return (object) array_filter(array('firstName' => $this->firstName, 'lastName' => $this->lastName, 'age' => $this->age), static function ($value) : bool {
            return $value !== null;
        });
    }
}

Now we can parse raw JSON data and fill this in to our object model:

// the data which we want to import
$data = json_decode('{"firstName": "foo", "lastName": "bar"}');

$schemaManager = new SchemaManager();

// we read the schema from the class
$schema = $schemaManager->getSchema(Person::class);

try {
    $person = (new SchemaTraverser())->traverse($data, $schema, new TypeVisitor());
    
    // $example contains now an instance of the Person class containing 
    // the firstName and lastName property
    echo $person->getFirstName();

} catch (\PSX\Schema\Exception\ValidationException $e) {
    // the validation failed
    echo $e->getMessage();
}

Every generated PHP class implements also the JsonSerializable interface so you can simply encode an object to json.

$schema = new Person();
$schema->setFirstName('foo');
$schema->setLastName('bar');
$schema->setAge(12);

echo json_encode($schema);

// would result in
// {"firstName": "foo", "lastName": "bar", "age": 12}

Generator

Beside PHP classes this library can generate the following types:

• CSharp
• Go
• GraphQL
• HTML
• Java
• JsonSchema
• Kotlin
• Markdown
• PHP
• Protobuf
• Python
• Ruby
• Rust
• Swift
• TypeSchema
• TypeScript
• VisualBasic

Attributes

The following attributes are available:

Attribute	Target	Example
Deprecated	Property	#[Deprecated(true)]
Description	Class/Property	#[Description("content")]
Discriminator	Property	#[Discriminator("type")]
Enum	Property	#[Enum(bar)]
Exclude	Property	#[Exclude]
ExclusiveMaximum	Property	#[ExclusiveMaximum(true)]
ExclusiveMinimum	Property	#[ExclusiveMinimum(true)]
Format	Property	#[Format("uri")]
Key	Property	#[Key("$ref")]
Maximum	Property	#[Maximum(16)]
MaxItems	Property	#[MaxItems(16)]
MaxLength	Property	#[MaxLength(16)]
MaxProperties	Class	#[MaxProperties(16)]
Minimum	Property	#[Minimum(4)]
MinItems	Property	#[MinItems(4)]
MinLength	Property	#[MinLength(4)]
MinProperties	Property	#[MinProperties(4)]
MultipleOf	Property	#[MultipleOf(2)]
Nullable	Property	#[Nullable(true)]
Pattern	Property	#[Pattern("A-z+")]
Required	Class	#[Required(["name", "title"])]
Title	Class	#[Title("foo")]
UniqueItems	Property	#[UniqueItems(true)]