Structure

A structure (or 'struct') is a composite of primitive types that always takes the same form.

To define a struct, create a class that implements the StageRightLabs\PhpXdr\Interfaces\XdrStruct interface. This interface has two methods:

• toXdr(XDR &$xdr): void: Use an XDR buffer to compose the data that makes up the structure.
• static newFromXdr(XDR &$xdr): static: Read data from an XDR buffer and return a new instance of the class.

NB: unlike other composite type interfaces, this package cannot encode and decode the value of a struct automatically. Instead you must implement this in the methods described above. Both methods are given a reference to an XDR buffer from which you can read and write as needed.

For example:

use StageRightLabs\PhpXdr\XDR;
use StageRightLabs\PhpXdr\Interfaces\XdrStruct;

class HighScore implements XdrStruct
{
    public function __construct(public int $score, public string $name)
    {
        $this->score = $score;
        $this->name = $name;
    }
    
    public function toXdr(XDR &$xdr): void {
        $xdr->write($this->score, XDR::INT);
        $xdr->write($this->name, XDR::STRING);
    }

    public static function newFromXdr(XDR &$xdr): static
    {
        $score = $xdr->read(XDR::INT);
        $name = $xdr->read(XDR::STRING);
        return new static($score, $name);
    }
}

To encode a struct:

use StageRightLabs\PhpXdr\XDR;

$highScore = new HighScore(score: 256, name: 'Hiro Protagonist');
$xdr = XDR::fresh()->write($highScore, XDR::STRUCT);

To decode a struct:

$highScore = $xdr->read(XDR::STRUCT, HighScore::class);
$highScore->score == 256; // true
$highScore->name == 'Hiro Protagonist'; // true