PHP 5.4.33 Released

JsonSerializable::jsonSerialize

(PHP 5 >= 5.4.0)

JsonSerializable::jsonSerializeSpécifie les données qui doivent être linéarisées en JSON

Description

abstract public mixed JsonSerializable::jsonSerialize ( void )

Linéarise l'objet en une valeur qui peut être linéarisé nativement par la fonction json_encode().

Liste de paramètres

Cette fonction ne contient aucun paramètre.

Valeurs de retour

Retourne les données qui peuvent être linéarisées par la fonction json_encode(), qui peuvent être des valeurs de n'importe quel type autre qu'une ressource.

Exemples

Exemple #1 Exemple avec JsonSerializable::jsonSerialize() retournant un tableau

<?php
class ArrayValue implements JsonSerializable {
    public function 
__construct(array $array) {
        
$this->array $array;
    }

    public function 
jsonSerialize() {
        return 
$this->array;
    }
}

$array = [123];
echo 
json_encode(new ArrayValue($array), JSON_PRETTY_PRINT);
?>

L'exemple ci-dessus va afficher :

[
    1,
    2,
    3
]

Exemple #2 Exemple avec JsonSerializable::jsonSerialize() retournant un tableau associatif

<?php
class ArrayValue implements JsonSerializable {
    public function 
__construct(array $array) {
        
$this->array $array;
    }

    public function 
jsonSerialize() {
        return 
$this->array;
    }
}

$array = ['foo' => 'bar''quux' => 'baz'];
echo 
json_encode(new ArrayValue($array), JSON_PRETTY_PRINT);
?>

L'exemple ci-dessus va afficher :

{
    "foo": "bar",
    "quux": "baz"
}

Exemple #3 Exemple avec JsonSerializable::jsonSerialize() retournant un entier

<?php
class IntegerValue implements JsonSerializable {
    public function 
__construct($number) {
        
$this->number = (integer) $number;
    }

    public function 
jsonSerialize() {
        return 
$this->number;
    }
}

echo 
json_encode(new IntegerValue(1), JSON_PRETTY_PRINT);
?>

L'exemple ci-dessus va afficher :

1

Exemple #4 Exemple avec JsonSerializable::jsonSerialize() retournant une chaîne de caractères

<?php
class StringValue implements JsonSerializable {
    public function 
__construct($string) {
        
$this->string = (string) $string;
    }

    public function 
jsonSerialize() {
        return 
$this->string;
    }
}

echo 
json_encode(new StringValue('Hello!'), JSON_PRETTY_PRINT);
?>

L'exemple ci-dessus va afficher :

"Hello!"

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User Contributed Notes 3 notes

up
19
benkuhl at gmail dot com
1 year ago
A good example on when you would use functionality like this is when working with objects.

json_encode() will take a DateTime and convert it to:

{
    "date":"2013-01-31 11:14:05",
    "timezone_type":3,
    "timezone":"America\/Los_Angeles"
}

This is great when working with PHP, but if the Date is being read by Java.  The Java date parser doesn't know what to do with that.  But it does know what to do with the ISO8601 format...

<?php

date_default_timezone_set
('America/Los_Angeles');

class
Fruit implements JsonSerializable {
    public
       
$type = 'Apple',
       
$lastEaten = null;

    public function
__construct() {
       
$this->lastEaten = new DateTime();
    }

    public function
jsonSerialize() {
        return [
           
'type' => $this->type,
           
'lastEaten' => $this->lastEaten->format(DateTime::ISO8601)
        ];
    }
}
echo
json_encode(new Fruit()); //which outputs: {"type":"Apple","lastEaten":"2013-01-31T11:17:07-0500"}

?>
up
1
dimstefan83 at gmail dot com
3 months ago
simple functions to make life easier.
I wanted a way to have a as property value the return value of a method in order to have it initialized. example

class portItem implements JsonSerializable{
    private $idPort;
    private $location;
    private $portLanguages;

    public function getLocation() {
        if(!isset($this->location)){
            return new locationItem();
        }
        return $this->location;
    }

    public function setLocation($location) {
        $this->location = $location;
    }

      public function setidPort($idPort){
        $this->idPort=$idPort;
    }
   
    public function getidPort(){
        if(!isset($this->idPort)){
            return 0;
        }
        return intval($this->idPort);
    }
    public function setPortLanguages($portLanguages){
        $this->portLanguages=$portLanguages;
    }
   
    public function getPortLanguages(){
        if(!isset($this->portLanguages)){
            return new genericItems();
        }
        return $this->portLanguages;
    }
   
    public function getCategoryLanguages(){
        if(!isset($this->portLanguages)){
            return new genericItems();
        }
        return $this->portLanguages;
    }
   
    public function getPortLanguageAtIndex($index=false){
        if(!$index){
            $index=0;
        }
        return $this->portLanguages[$index];
    }
   
    public function setPortLanguageAtIndex($index,$language){
        $this->portLanguages[$index]=$language;
    }

        public function jsonSerialize() {
        $dataConverter = new dataConverter();
        return $dataConverter->convertToJson($this);
    }

}

Wit 2 ways you can automatically convert for json.
1.by reading properties
public function convertToJson($object){
        /*approch by using object properties*/
        $class = get_class($this);
        $json = array();
        $properties = get_class_vars($class);
        $keys = array_keys($properties);
        $plength = count($keys);
        for($i=0;$i<$plength;$i++){
            $method =  "get".$keys[$i];
            if(method_exists ($this,$method)){
                $json[$keys[$i]] = $this->$method();
            }
        }
return $json;
}

public function convertToJson($object){    
/*approch by using object methods*/
        $class = get_class($object);
        $json = array();
        $methods = get_class_methods($class);
        $plength = count($methods);
        $json = array();
        for($i=0;$i<$plength;$i++){
            if(stripos($methods[$i], "get")!==FALSE){
                $property = mb_substr($methods[$i], 3,mb_strlen($methods[$i],'UTF-8'),'UTF-8');
                $setter = "set".mb_substr($methods[$i], 3,mb_strlen($methods[$i],'UTF-8'),'UTF-8');
                if(method_exists($object,$setter)){
                    $json[$property] = $object->$methods[$i]();
                }
               
            }
        }
       
        return $json;
    }

By using this method the result will be a json with value for properties initialized according to each method.

Things to note
1.if you are using the reading properties approach the code cant' work outside of the class for private properties, because they are nto visible, you have to put it the code directly to public function jsonSerialize() {} in order to work.
2.For both approaches has method seems not to be case sensitive else you are going to have problems, i strongly suggest to pay attention in naming convention between property names and method names idPort =>setIdPort() =>getIdPort() (i know my class is done not that way).
3.both approaches since you call method without knowing the arguments you need to pay attention in arguments for getter methods where applicable, check my example
public function getPortLanguageAtIndex($index=false){
        if(!$index){
            $index=0;
        }
        return $this->portLanguages[$index];
    }
that's why i have set it to optional argument. If you don't do that php will complain about missing argument parameter in method XXX.
up
-2
simonsimcity at gmail dot com
5 months ago
You can't throw exceptions in here. If you do, you'll get an exception with the message "Failed calling FooClass::jsonSerialize()" and the stacktrace will start at where you called the json_encode() method.

Here's a code-example:

class Foo implements JsonSerializable {
    private $triggerError = true;

    public function jsonSerialize()
    {
        if ($this->triggerError) {
            throw new RuntimeException("It failed!");
        }

        return (array)$this;
    }
}

// Will throw an exception like new Exception("Failed calling Foo::jsonSerialize()")
json_encode(new Foo());
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