Magento 2.4 get template file in data patch

Question

I'm trying to insert a template file as the content for the block I'm adding programmatically, but I'm not sure how this can be done. I've added the template file in view/frontend/templates/template-file.phtml

    public function __construct(
        BlockFactory $blockFactory,
        Block $blockResourceModel
    ) {
        $this->blockFactory = $blockFactory;
        $this->blockResourceModel = $blockResourceModel;
    }

    /**
     * {@inheritdoc}
     *
     * @return void
     * @throws \Exception
     */
    public function apply()
    {
        $cmsBlock = [
            'title' => 'Footer content',
            'identifier' => 'footer_content',
            'content' => <How to insert template file here?>,
            'is_active' => 1,
            'store_id' => [9]
        ];
        $block = $this->blockFactory->create();
        $block->setData($cmsBlock);
        $this->blockResourceModel->save($block);
    }

Answer 1

I guess you need to check how the block is binding with template file and how layout file works.

Check it out in the following article.

https://www.mageplaza.com/magento-2-module-development/view-block-layout-template-magento-2.html#step-3-create-block

Answer 2

Ended up with using Magento\Framework\Filesystem\Driver\File

    public function __construct(
        BlockFactory $blockFactory,
        Block $blockResourceModel,
        File $filesystemDriver
    ) {
        $this->blockFactory = $blockFactory;
        $this->blockResourceModel = $blockResourceModel;
        $this->filesystemDriver = $filesystemDriver;
    }

    /**
     * {@inheritdoc}
     *
     * @return void
     * @throws \Exception
     */
    public function apply()
    {
        $fileContents = $this->filesystemDriver->fileGetContents(
            'app/code/Vendor/Module/view/frontend/templates/template-file.phtml'
        );
        $cmsBlock = [
            'title' => 'Footer content',
            'identifier' => 'footer_content',
            'content' => $fileContents,
            'is_active' => 1,
            'store_id' => [9]
        ];
        $block = $this->blockFactory->create();
        $block->setData($cmsBlock);
        $this->blockResourceModel->save($block);
    }

Answer 3

I ended up emulating the admin area and getting the contents of the template file within there.

/**
 * @return string
 * @throws \Exception
 */
private function getCmsBlockContent(): string
{
    $content = $this->state->emulateAreaCode(Area::AREA_ADMINHTML, function () {
        $layout = ObjectManager::getInstance()->get(LayoutInterface::class);
        return $layout->createBlock(Template::class)->setTemplate(self::TEMPLATE_FILE)->toHtml();
    });

    return (string) $content;
}