Serializer for PHP

• Installation
• Introduction
• Features
• Serialization
  • Serializers (JSON, XML, YAML)
  • Example
  • Custom Serializers
• Data Transformation
  • Array Transformer
  • Flat Array Transformer
  • XML Transformer
  • YAML Transformer
  • JSON Transformer
  • JSend Transformer
  • JSON API Transformer
  • HAL+JSON Transformer
• Quality
• Contribute
• Author
• License

Installation

Use Composer to install the package:

$ composer require nilportugues/serializer

Introduction

What is serialization?

In the context of data storage, serialization is the process of translating data structures or object state into a format that can be stored (for example, in a file or memory buffer, or transmitted across a network connection link) and reconstructed later in the same or another computer environment.

Why not serialize() and unserialize()?

These native functions rely on having the serialized classes loaded and available at runtime and tie your unserialization process to a PHP platform.

If the serialized string contains a reference to a class that cannot be instantiated (e.g. class was renamed, moved namespace, removed or changed to abstract) PHP will immediately die with a fatal error.

Is this a problem? Yes it is. Serialized data is now unusable.

Features

• Serialize to JSON, XML and YAML formats.
• Serializes exact copies of the object provided:
• All object properties, public, protected and private are serialized.
• All properties from the current object, and all the inherited properties are read and serialized.
• Handles internal class serialization for objects such as SplFixedArray or classes implementing Traversable.
• Basic Data Transformers provided to convert objects to different output formats.
• Production-ready.
• Extensible: easily write your out Serializer format or data Transformers.

Serialization

For the serializer to work, all you need to do is pass in a PHP Object to the serializer and a Strategy to implement its string representation.

Serializers (JSON, XML, YAML)

• NilPortugues\Serializer\JsonSerializer
• NilPortugues\Serializer\XmlSerializer
• NilPortugues\Serializer\YamlSerializer

Example

In the following example a $post object is serialized into JSON.

Code

use NilPortugues\Serializer\Serializer;
use NilPortugues\Serializer\Strategy\JsonStrategy;

//Example object
$post = new Post(
  new PostId(9),
  'Hello World',
  'Your first post',
  new User(
      new UserId(1),
      'Post Author'
  ),
  [
      new Comment(
          new CommentId(1000),
          'Have no fear, sers, your king is safe.',
          new User(new UserId(2), 'Barristan Selmy'),
          [
              'created_at' => (new DateTime('2015/07/18 12:13:00'))->format('c'),
              'accepted_at' => (new DateTime('2015/07/19 00:00:00'))->format('c'),
          ]
      ),
  ]
);

//Serialization 
$serializer = new JsonSerializer();

$serializedObject = $serializer->serialize($post);

//Returns: true
var_dump($post == $serializer->unserialize($serializedObject));

echo $serializedObject;

The object, before it's transformed into an output format, is an array with all the necessary data to be rebuild using unserialize method.

Output

{
    "@type": "Acme\\\\Domain\\\\Dummy\\\\Post",
    "postId": {
        "@type": "Acme\\\\Domain\\\\Dummy\\\\ValueObject\\\\PostId",
        "postId": {
            "@scalar": "integer",
            "@value": 14
        }
    },
    "title": {
        "@scalar": "string",
        "@value": "Hello World"
    },
    "content": {
        "@scalar": "string",
        "@value": "Your first post"
    },
    "author": {
        "@type": "Acme\\\\Domain\\\\Dummy\\\\User",
        "userId": {
            "@type": "Acme\\\\Domain\\\\Dummy\\\\ValueObject\\\\UserId",
            "userId": {
                "@scalar": "integer",
                "@value": 1
            }
        },
        "name": {
            "@scalar": "string",
            "@value": "Post Author"
        }
    },
    "comments": {
        "@map": "array",
        "@value": [
            {
                "@type": "Acme\\\\Domain\\\\Dummy\\\\Comment",
                "commentId": {
                    "@type": "Acme\\\\Domain\\\\Dummy\\\\ValueObject\\\\CommentId",
                    "commentId": {
                        "@scalar": "integer",
                        "@value": 1000
                    }
                },
                "dates": {
                    "@map": "array",
                    "@value": {
                        "created_at": {
                            "@scalar": "string",
                            "@value": "2015-07-18T12:13:00+00:00"
                        },
                        "accepted_at": {
                            "@scalar": "string",
                            "@value": "2015-07-19T00:00:00+00:00"
                        }
                    }
                },
                "comment": {
                    "@scalar": "string",
                    "@value": "Have no fear, sers, your king is safe."
                },
                "user": {
                    "@type": "Acme\\\\Domain\\\\Dummy\\\\User",
                    "userId": {
                        "@type": "Acme\\\\Domain\\\\Dummy\\\\ValueObject\\\\UserId",
                        "userId": {
                            "@scalar": "integer",
                            "@value": 2
                        }
                    },
                    "name": {
                        "@scalar": "string",
                        "@value": "Barristan Selmy"
                    }
                }
            }
        ]
    }
}'

Custom Serializers

If a custom serialization strategy is preferred, the Serializer class should be used instead. A CustomStrategy must implement the StrategyInterface.

Usage is as follows:

use NilPortugues\Serializer\Serializer;
use NilPortugues\Serializer\Strategy\CustomStrategy;

$serializer = new Serializer(new CustomStrategy());

echo $serializer->serialize($post);

---

Data Transformation

Transformer classes greatly differ from a Strategy class because these cannot unserialize() as all class references are lost in the process of transformation.

To obtain transformations instead of the Serializer class usage of DeepCopySerializer is required.

The Serializer library comes with a set of defined Transformers that implement the StrategyInterface. Usage is as simple as before, pass a Transformer as a $strategy.

For instance:

//...same as before ...

$serializer = new DeepCopySerializer(new JsonTransformer());
echo $serializer->serialize($post);

Following, there are some examples and its output, given the $post object as data to be Transformed.

Array Transformer

• NilPortugues\Serializer\Transformer\ArrayTransformer

array(
  'postId' => 9,
  'title' => 'Hello World',
  'content' => 'Your first post',
  'author' => array(
       'userId' => 1,
       'name' => 'Post Author',
   ),
  'comments' => array(
          0 => array(
           'commentId' => 1000,
           'dates' => array(
              'created_at' => '2015-07-18T12:13:00+02:00',
              'accepted_at' => '2015-07-19T00:00:00+02:00',
            ),
           'comment' => 'Have no fear, sers, your king is safe.',
           'user' => array(
             'userId' => 2,
             'name' => 'Barristan Selmy',
            ),
          ),
      ),
);

Flat Array Transformer

• NilPortugues\Serializer\Transformer\FlatArrayTransformer

array(
  'postId' => 9,
  'title' => 'Hello World',
  'content' => 'Your first post',
  'author.userId' => 1,
  'author.name' => 'Post Author',
  'comments.0.commentId' => 1000,
  'comments.0.dates.created_at' => '2015-07-18T12:13:00+02:00',
  'comments.0.dates.accepted_at' => '2015-07-19T00:00:00+02:00',
  'comments.0.comment' => 'Have no fear, sers, your king is safe.',
  'comments.0.user.userId' => 2,
  'comments.0.user.name' => 'Barristan Selmy',
);

XML Transformer

• NilPortugues\Serializer\Transformer\XmlTransformer

<?xml version="1.0" encoding="UTF-8"?>
<data>
  <postId type="integer">9</postId>
  <title type="string">Hello World</title>
  <content type="string">Your first post</content>
  <author>
    <userId type="integer">1</userId>
    <name type="string">Post Author</name>
  </author>
  <comments>
    <sequential-item>
      <commentId type="integer">1000</commentId>
      <dates>
        <created_at type="string">2015-07-18T12:13:00+02:00</created_at>
        <accepted_at type="string">2015-07-19T00:00:00+02:00</accepted_at>
      </dates>
      <comment type="string">Have no fear, sers, your king is safe.</comment>
      <user>
        <userId type="integer">2</userId>
        <name type="string">Barristan Selmy</name>
      </user>
    </sequential-item>
  </comments>
</data>

YAML Transformer

• NilPortugues\Serializer\Transformer\YamlTransformer

title: 'Hello World'
content: 'Your first post'
author:
    userId: 1
    name: 'Post Author'
comments:
    - { commentId: 1000, dates: { created_at: '2015-07-18T12:13:00+02:00', accepted_at: '2015-07-19T00:00:00+02:00' }, comment: 'Have no fear, sers, your king is safe.', user: { userId: 2, name: 'Barristan Selmy' } }

Json Transformer

JsonTransformer comes in 2 flavours. For object to JSON transformation the following transformer should be used:

• NilPortugues\Serializer\Transformer\JsonTransformer

Output

{
    "postId": 9,
    "title": "Hello World",
    "content": "Your first post",
    "author": {
        "userId": 1,
        "name": "Post Author"
    },
    "comments": [
        {
            "commentId": 1000,
            "dates": {
                "created_at": "2015-07-18T13:34:55+02:00",
                "accepted_at": "2015-07-18T14:09:55+02:00"
            },
            "comment": "Have no fear, sers, your king is safe.",
            "user": {
                "userId": 2,
                "name": "Barristan Selmy"
            }
        }
    ]
}

If your desired output is for API consumption, you may like to check out the JsonTransformer library, or require it using:

$ composer require nilportugues/json

JSend Transformer

JSend Transformer has been built to transform data into valid JSend specification resources.

Please check out the JSend Transformer or download it using:

$ composer require nilportugues/jsend

JSON API Transformer

JSON API Transformer has been built to transform data into valid JSON API specification resources.

Please check out the JSON API Transformer or download it using:

$ composer require nilportugues/json-api

HAL+JSON Transformer

HAL+JSON Transformer has been built for HAL+JSON API creation. Given an object and a series of mappings a valid HAL+JSON resource representation is given as output.

Please check out the HAL+JSON API Transformer or download it using:

$ composer require nilportugues/haljson

---

Quality

To run the PHPUnit tests at the command line, go to the tests directory and issue phpunit.

This library attempts to comply with PSR-2 and PSR-4.

If you notice compliance oversights, please send a patch via pull request.

Contribute

Contributions to the package are always welcome!

• Report any bugs or issues you find on the issue tracker.
• You can grab the source code at the package's Git repository.

Authors

• Nil Portugués Calderó
• The Community Contributors

License

The code base is licensed under the MIT license.