(JSON) object mapper

A simple library to deserialize JSON into (nested) PHP arrays / objects.

Requirements

• PHP 7.2 or higher

Installation

You can use Composer or simply Download the Release

Composer

The preferred method is via composer. Follow the installation instructions if you do not already have composer installed.

Once composer is installed, execute the following command in your project root to install this library:

composer require radebatz/object-mapper

Usage

Simple model using getXXX()/setXXX()

use Radebatz\ObjectMapper\ObjectMapper;

class MyClass 
{
    protected $foo;
    
    public function getFoo()
    {
        return $this->foo;
    }
    
    public function setFoo($foo) 
    {
        $this->foo = $foo;
    }
}

    
$objectMapper = new ObjectMapper();

$json = '{"foo":"bar"}';

/** @var \MyClass $obj */
$obj = $objectMapper->map($json, \MyClass::class);

echo $obj->getFoo(); // 'bar'

Value union using interface

use Radebatz\ObjectMapper\ObjectMapper;
use Radebatz\ObjectMapper\ValueTypeResolverInterface;

interface ValueInterface
{
    public function getType(): string;
}

class Tree implements ValueInterface
{
    public function getType(): string
    {
        return "tree";
    }
}

class Flower implements ValueInterface
{
    public function getType(): string
    {
        return "flower";
    }
}

$objectMapper = new ObjectMapper();
$objectMapper->addValueTypeResolver(
    new class() implements ValueTypeResolverInterface {
        public function resolve($className, $json): ?string
        {
            if (is_object($json) && \ValueInterface::class == $className) {
                if (property_exists($json, 'type')) {
                    switch ($json->type) {
                        case 'tree':
                            return \Tree::class;
                        case 'flower':
                            return \Flower::class;
                    }
                }
            }

            return null;
        }
    }
);

$json = '{"type": "flower"}';

/** @var \ValueInterface $obj */
$obj = $objectMapper->map($json, \ValueInterface::class);

echo get_class($obj); // '\Flower'

    $objectMapper->addValueTypeResolver(
        new class() implements ValueTypeResolverInterface {
            public function resolve($className, $json): ?string
            {
                if (is_object($json) && PopoInterface::class == $className) {
                    if (property_exists($json, 'foo')) {
                        return AnotherPopo::class;
                    }

                    return SimplePopo::class;
                }

                return null;
            }
        }
    );

Configuration

The ObjectMapper class takes an array (map) as first constructor argument which allows to customise the behaviour when mapping data. All option names (keys) are defined as class constants.

OPTION_STRICT_TYPES

Enforces strict type checking on build in data types (excluding array).

Default: true

OPTION_STRICT_COLLECTIONS

Enforces strict type checking on arrays.

Default: true

OPTION_STRICT_NULL

Enforces strict check on null value assignments.

Default: true

OPTION_IGNORE_UNKNOWN

Enable/disable reporting unmapped properties (will throw ObjectMapperException).

Default: true

OPTION_VERIFY_REQUIRED

If enabled check if all properties with a @required annotation have been mapped (will throw ObjectMapperException).

Default: false

OPTION_INSTANTIATE_REQUIRE_CTOR

If disabled, object instantiation will fall back to ReflectionClass::newInstanceWithoutConstructor() if a regular new $class() fails. Futhermore, if set it will enforce a constructor argument check in case a scalar is deserialized into an object.

Default: true

OPTION_UNKNOWN_PROPERTY_HANDLER

Optional callable to handle unknown/unmappable properties. Signature:

function ($obj, $key, $value) {}

The return value is epected to be either a property name or null.

Default: null

OPTION_VARIADIC_SETTER

If enabled, setting list values will allow variadic parameters on models (requires 5.2 >= PropertyAccess).

class Model {
  private $list = [];
  public function setList(ListModel ... $listModels) {
    $this->list = $listModels;  
  }
}

The return value is expected to be either a property name or null.

Default: false

Testing

This package is inspired by the excellent jsonmapper package. In order to evaluate its features, the tests folder contains an adapter that lets you run the jsonmapper test suite agaist the json-object-manager codebase.

For this you run:

rm -rf vendor/netresearch/jsonmapper && composer install --prefer-source
./vendor/bin/phpunit -c phpunit.xml.jsonmapper

Not all tests pass as this library support also, for example, mapping scalar values. As it stands the result of running the tests is:

Tests: 104, Assertions: 249, Errors: 2, Failures: 14.  (jsonmapper 4.x)

The tests use a custom JsonMapper class that internally uses the ObjectMapper.