BarcodeService.php

<?php

namespace Barcode;

use Traversable;
use Barcode\Builder\ObjectBuilderInterface as ObjectBuilder;
use Barcode\Builder\RendererBuilderInterface as RendererBuilder;
use Barcode\Object\SpecificationInterface as ObjectSpecification;
use Barcode\Renderer\SpecificationInterface as RenderSpecification;

/**
 * The application service should provide a simple interface which hides the
 * domain-specific implementation details.
 */
interface ServiceInterface
{
    /**
     * Encode the text into a rendered barcode
     *
     * @param  string                                $text       the text to encode
     * @param  ObjectSpecification|array|Traversable $objectSpec the object specification
     * @param  RenderSpecification|array|Traversable $renderSpec the render specification
     * @return mixed
     */
    public function encode($text, $objectSpec, $renderSpec);

    /**
     * Get the object builder
     *
     * @return ObjectBuilder
     */
    public function objectBuilder();

    /**
     * Get the renderer builder
     *
     * @return RendererBuilder
     */
    public function rendererBuilder();
}

Format.php

<?php

namespace Barcode;

use Util\ValueTrait;

final class Format
{
    use ValueTrait;
    
    const ASCII = 'ascii';
    const GIF   = 'gif';
    const JPEG  = 'jpeg';
    const PDF   = 'pdf';
    const PNG   = 'png';
    const SVG   = 'svg';
    
    protected static $validValues = [
        self::ASCII,
        self::GIF,
        self::JPEG,
        self::PDF,
        self::PNG,
        self::SVG
    ];
}

ObjectBuilder.php

<?php

namespace Barcode\Builder;

use Traversable;
use Barcode\Object\ObjectInterface;
use Barcode\Object\SpecificationInterface;

interface ObjectBuilderInterface extends BuilderInterface
{
    /**
     * Build a barcode object
     *
     * @param  SpecificationInterface|array|Traversable $objectSpec the object specification
     * @param  string|null                              $text       optional barcode text
     * @return ObjectInterface
     */
    public function build($objectSpec, $text = null);
}

RendererBuilder.php

<?php

namespace Barcode\Builder;

use Traversable;
use Barcode\Renderer\RendererInterface;
use Barcode\Renderer\SpecificationInterface;

interface RendererBuilderInterface extends BuilderInterface
{
    /**
     * Build a barcode renderer
     *
     * @param  SpecificationInterface|array|Traversable $renderSpec the render specification
     * @return RendererInterface
     */
    public function build($renderSpec);
}

Type.php

<?php

namespace Barcode;

use Util\ValueTrait;

final class Type
{
    use ValueTrait;
    
    const CODABAR = 'codabar';
    const CODE25  = 'code25';
    const CODE25I = 'code25i';
    const CODE39  = 'code39';
    const CODE128 = 'code128';
    const EAN2    = 'ean2';
    const EAN8    = 'ean8';
    const EAN13   = 'ean13';
    // etc.
    
    protected static $validValues = [
        self::CODABAR,
        self::CODE25,
        self::CODE25I,
        self::CODE39,
        self::CODE128,
        self::EAN2,
        self::EAN8,
        self::EAN13,
        // etc.
    ];
}

ValueTrait.php

<?php

namespace Util;

use DomainException;

trait ValueTrait
{
    private $value;
    
    public function __construct($value)
    {
        if (!in_array($values, static::$validValues)) {
            throw new DomainException("Invalid value [$value]");
        }
        $this->value = $value;
    }
    
    public static function __callStatic($value, array $arguments = [])
    {
        return new static(strtolower($value));
    }
    
    public function is($other)
    {
        if (is_string($other)) {
            $other = static::__callStatic($other);
        }
        return $this == $other;
    }
    
    public function value()
    {
        return $this->value;
    }
    
    public function __toString()
    {
        return $this->value();
    }
}