invoiceninja/app/Utils/Traits/MakesInvoiceHtml.php

<?php
/**
 * Invoice Ninja (https://invoiceninja.com)
 *
 * @link https://github.com/invoiceninja/invoiceninja source repository
 *
 * @copyright Copyright (c) 2019. Invoice Ninja LLC (https://invoiceninja.com)
 *
 * @license https://opensource.org/licenses/AAL
 */

namespace App\Utils\Traits;

use Illuminate\Support\Facades\Blade;
use Symfony\Component\Debug\Exception\FatalThrowableError;


/**
 * Class MakesInvoiceHtml.
 */
trait MakesInvoiceHtml
{

    /**
     * Generate the HTML invoice parsing variables 
     * and generating the final invoice HTML
     *     
     * @param  string $design either the path to the design template, OR the full design template string
     * @param  Collection $invoice  The invoice object
     * 
     * @return string           The invoice string in HTML format
     */
    public function generateInvoiceHtml($design, $invoice) :string
    {

        $variables = array_merge($invoice->makeLabels(), $invoice->makeValues());
        $design = str_replace(array_keys($variables), array_values($variables), $design);

        $data['invoice'] = $invoice;

        return $this->renderView($design, $data);

        //return view($design, $data)->render();

    }

    /**
     * Parses the blade file string and processes the template variables
     * 
     * @param  string $string The Blade file string
     * @param  array $data   The array of template variables
     * @return string         The return HTML string
     * 
     */
    public function renderView($string, $data) :string
    {
        if (!$data) {
        $data = [];
        }

        $data['__env'] = app(\Illuminate\View\Factory::class);

        $php = Blade::compileString($string);

        $obLevel = ob_get_level();
        ob_start();
        extract($data, EXTR_SKIP);

        try {
            eval('?' . '>' . $php);
        } catch (\Exception $e) {
            while (ob_get_level() > $obLevel) {
                ob_end_clean();
            }

            throw $e;
        } catch (\Throwable $e) {
            while (ob_get_level() > $obLevel) {
                ob_end_clean();
            }

            throw new FatalThrowableError($e);
        }

        return ob_get_clean();
    }

}