MongoDB\BSON\Serializable::bsonSerialize

Provides an array or document to serialize as BSON

&reftitle.description; abstract public ``array``stdClass``MongoDB\BSON\Document``MongoDB\BSON\PackedArray```MongoDB\BSON\Serializable::bsonSerialize`

Called during serialization of the object to BSON. The method must return an `array`, `stdClass`, `MongoDB\BSON\Document`, or `MongoDB\BSON\PackedArray`.

Root documents (e.g. a MongoDB\BSON\Serializable passed to `MongoDB\BSON\fromPHP`) will always be serialized as a BSON document. For field values, associative arrays and `stdClass` instances will be serialized as a BSON document and sequential arrays (i.e. sequential, numeric indexes starting at `0`) will be serialized as a BSON array.

Users are encouraged to include an `_id` property (e.g. a `MongoDB\BSON\ObjectId` initialized in your constructor) when returning data for a BSON root document; otherwise, the driver or database will need to generate a `MongoDB\BSON\ObjectId` when inserting or upserting the document, respectively.

&reftitle.parameters; &no.function.parameters;
&reftitle.returnvalues;

An `array`, `stdClass`, `MongoDB\BSON\Document`, or `MongoDB\BSON\PackedArray` to be serialized as a BSON array or document.

&reftitle.changelog;

&Version; | &Description;
PECL mongodb 1.17.0 | The return type was changed from ``array``object``. Instead of `object`, the return type now specifies `stdClass`. Classes that implement this interface must be changed to no longer declare an `object` return type. As the return type is tentative, a deprecation warning is emitted on PHP 8.1 and newer. In addition to the changes above, the driver now also supports returning instances of `MongoDB\BSON\Document` and `MongoDB\BSON\PackedArray`. Please note that any `MongoDB\BSON\PackedArray` instances returned are silently converted to objects when stored as root documents. They are stored as arrays when used as an embedded field value.

&reftitle.examples;

### `MongoDB\BSON\Serializable::bsonSerialize` returning an associative array for root document

    <?php

    class MyDocument implements MongoDB\BSON\Serializable
    {
        private $id;

        function __construct()
        {
            $this->id = new MongoDB\BSON\ObjectId;
        }

        function bsonSerialize(): array
        {
            return ['_id' => $this->id, 'foo' => 'bar'];
        }
    }

    $bson = MongoDB\BSON\fromPHP(new MyDocument);
    echo MongoDB\BSON\toJSON($bson), "\n";

    ?>

&example.outputs.similar;

    { "_id" : { "$oid" : "56cccdcada14d8755a58c591" }, "foo" : "bar" }

### `MongoDB\BSON\Serializable::bsonSerialize` returning a sequential array for root document

    <?php

    class MyArray implements MongoDB\BSON\Serializable
    {
        function bsonSerialize(): array
        {
            return [1, 2, 3];
        }
    }

    $bson = MongoDB\BSON\fromPHP(new MyArray);
    echo MongoDB\BSON\toJSON($bson), "\n";

    ?>

&example.outputs;

    { "0" : 1, "1" : 2, "2" : 3 }

### `MongoDB\BSON\Serializable::bsonSerialize` returning an associative array for document field

    <?php

    class MyDocument implements MongoDB\BSON\Serializable
    {
        function bsonSerialize(): array
        {
            return ['foo' => 'bar'];
        }
    }

    $value = ['document' => new MyDocument];
    $bson = MongoDB\BSON\fromPHP($value);
    echo MongoDB\BSON\toJSON($bson), "\n";

    ?>

&example.outputs;

    { "document" : { "foo" : "bar" } }

### `MongoDB\BSON\Serializable::bsonSerialize` returning a sequential array for document field

    <?php

    class MyArray implements MongoDB\BSON\Serializable
    {
        function bsonSerialize(): array
        {
            return [1, 2, 3];
        }
    }

    $value = ['array' => new MyArray];
    $bson = MongoDB\BSON\fromPHP($value);
    echo MongoDB\BSON\toJSON($bson), "\n";

    ?>

&example.outputs;

    { "array" : [ 1, 2, 3 ] }

&reftitle.seealso;

- `MongoDB\BSON\Unserializable::bsonUnserialize`
- MongoDB\BSON\Persistable
- mongodb.persistence