Source of file TwigLayout.php

<?php

namespace BWF\DocumentTemplates\Layouts;

use BWF\DocumentTemplates\EditableTemplates\EditableTemplate;

use BWF\DocumentTemplates\EditableTemplates\EditableTemplateInterface;

use BWF\DocumentTemplates\EditableTemplates\HtmlTemplate;

use BWF\DocumentTemplates\Sandbox\SecurityPolicy;

use Twig\Environment;

use Twig\Extension\SandboxExtension;

use Twig\Loader\ArrayLoader;

use Twig\Loader\FilesystemLoader;

class TwigLayout extends Layout implements LayoutInterface

{

    /**

     * @var Environment

     */

    protected $twig;

    /**

     * @var \Twig\Extension\SandboxExtension

     */

    protected $sandbox;

    /**

     * @var \Twig\TemplateWrapper

     */

    protected $layout;

    /**

     * @var string Base path for template loading

     */

    protected $basePath;

    /**

     * TwigLayout constructor.

     */

    public function __construct()

    {

        $this->basePath = config('document_templates.layout_path');

        $this->createEnvironment();

    }

    /**

     * Creates the twig environment and sets the sets up the security policy.

     */

    private function createEnvironment(){

        $loader = new FilesystemLoader($this->basePath);

        $this->twig = new Environment($loader, config('document_templates.twig.environment'));

        $policy = new SecurityPolicy(

            config('document_templates.template_sandbox.allowedTags'),

            config('document_templates.template_sandbox.allowedFilters'),

            config('document_templates.template_sandbox.allowedMethods'),

            config('document_templates.template_sandbox.allowedProperties'),

            config('document_templates.template_sandbox.allowedFunctions')

        );

        $this->sandbox = new \Twig\Extension\SandboxExtension($policy);

        $this->twig->addExtension($this->sandbox);

    }

    /**

     * @param string $template

     * @return mixed|void

     * @throws \Twig\Error\LoaderError

     * @throws \Twig\Error\RuntimeError

     * @throws \Twig\Error\SyntaxError

     */

    public function load($template)

    {

        $this->createEnvironment();

        $templateName = basename($template);

        $this->setName($templateName);

        $this->layout = $this->twig->load($templateName);

    }

    /**

     * return string[]

     */

    public function getAvailableLayouts()

    {

        $files = [];

        $iterator = new \DirectoryIterator($this->basePath);

        /** @var \SplFileInfo $fileinfo */

        foreach ($iterator as $fileinfo) {

            if (!$fileinfo->isDot() && $fileinfo->getExtension() === 'twig') {

                $files[] = $fileinfo->getBasename();

            }

        }

        return collect($files);

    }

    public function getTemplates()

    {

        $templates = [];

        if(!$this->layout) {

            throw new \Exception('Layout is not loaded!');

        }

        //It is necessary to load the template again, without this, the rendering fails when used with Laravel queues.

        $this->load($this->name);

        $context = $this->layout->getSourceContext();

        $blocks = $this->layout->getBlockNames([$context]);

        foreach ($blocks as $block) {

            $template = new EditableTemplate();

            $template->setName($block);

            $templates[] = $template;

        }

        return collect($templates);

    }

    protected function renderWithSandbox(EditableTemplateInterface $template, $templateData)

    {

        $this->sandbox->enableSandbox();

        $templateName = 'template_' . $template->getName();

        $loader = new ArrayLoader([

            $templateName => $template->getContent()

        ]);

        $this->twig->setLoader($loader);

        $rendered = $this->twig->render($templateName, $templateData);

        $this->sandbox->disableSandbox();

        return $rendered;

    }

    /**

     * Generates a new template by extending the layout with the given templates

     *

     * @param array $templates

     * @param  array $templateData

     * @return string

     */

    protected function extendLayout($templates, $templateData)

    {

        $extendedTemplate = '{% extends layout %}';

        foreach ($templates as $template) {

            $extendedTemplate .= sprintf(

                '{%% block %1$s %%}%2$s{%% endblock %1$s %%}',

                $template->getName(),

                $this->renderWithSandbox($template, $templateData)

            );

        }

        return $extendedTemplate;

    }

    /**

     * @param \BWF\DocumentTemplates\TemplateDataSources\TemplateDataSourceInterface[] $dataSources

     * @return array

     */

    protected function generateTemplateData($dataSources)

    {

        $templateData = [];

        foreach ($dataSources as $dataSource) {

            $templateData = array_merge($templateData, $dataSource->getTemplateData());

        }

        return $templateData;

    }

    /**

     * @param \BWF\DocumentTemplates\EditableTemplates\EditableTemplate[] $templates

     * @param \BWF\DocumentTemplates\TemplateDataSources\TemplateDataSourceInterface[] $dataSources

     * @return string

     * @throws \Twig\Error\LoaderError

     * @throws \Twig\Error\RuntimeError

     * @throws \Twig\Error\SyntaxError

     */

    public function render($templates, $dataSources)

    {

        $templateData = $this->generateTemplateData($dataSources);

        $templateData['layout'] = $this->layout;

        $loader = new ArrayLoader([

            'extendedLayout' => $this->extendLayout($templates, $templateData),

        ]);

        $this->twig->setLoader($loader);

        return $this->twig->render('extendedLayout', $templateData);

    }

    public function renderSingle(EditableTemplateInterface $template, $dataSources)

    {

        return $this->renderWithSandbox($template, $this->generateTemplateData($dataSources));

    }

}