How to render a Twig template in the element-api plugin (v2.5)

Question

I want to render a Twig template in an API endpoint. Specifically I need HTML for the JSON Feed field "content_html".

My attempts until now (inside the transformer function):

$view = Craft::$app->getView();
$template = $view->resolveTemplate('_blog-entry');

// first attempt:
$html = $view->render($template, ['entry' => $blogpost]);

// second attempt:
$controller = Craft::$app->createController('templates/render')[0];

$html = $controller->render($template, ['entry' => $blogpost])

But in both ways it says "Template not found" even if the path after the "resolveTemplate" is correct.

Has anybody an idea how to do it? Thanks!

Answer 1

You didn’t tell where that Twig file is located, but I assume your issue has to do with being in the wrong “Template Mode”.

Here’s how you can switch mode:

Craft::$app->view->setTemplateMode()

Documentation: https://docs.craftcms.com/v3/extend/updating-plugins.html#rendering-plugin-templates-on-front-end-requests

Answer 2

You're using $view->resolveTemplate('_blog-entry') which is returning the absolute path to the template as a string, and then passing that to $view->render which is expecting a relative path, not an absolute one. Internally I expect it's trying to run resolveTemplate on its argument, and it isn't sophisticated enough to recognize that a path is already absolute.

From your comment on the other answer it looks like you solved this, though didn't highlight it as the solution: just pass the relative template path straight to render; no need to use resolveTemplate first.

So corrected full code might be:

$view = Craft::$app->getView();
$html = $view->render('_blog-entry', ['entry' => $blogpost]);

I don't believe switching the template mode, as suggested in the other answer, is actually required, at least not under all circumstances.

Answer 3

I wrote a transformer class that does exactly this:

namespace your\awesome\namespace;

use Craft;
use craft\elements\Entry;
use League\Fractal\TransformerAbstract;
use craft\web\View;

/**
 * Class TwigTransformer
 * Renders a TWIG entry for each item
 */

class TwigTransformer extends TransformerAbstract
{
    private $twigTemplateFilePath;

    public function __construct($twigTemplateFilePath)
    {
        $this->twigTemplateFilePath = $twigTemplateFilePath;
    }

    public function transform(Entry $entry)
    {
        $oldMode = Craft::$app->view->getTemplateMode();
        Craft::$app->view->setTemplateMode(View::TEMPLATE_MODE_SITE);
        $html = Craft::$app->view->renderTemplate( $this->twigTemplateFilePath, ['entry' => $entry]);
        Craft::$app->view->setTemplateMode($oldMode);

        return [
            'id' => $entry->id,
            'html' => $html
        ];
    }
}

You could use the class likes this:

'transformer' => new TwigTransformer('includes/_overview-entry.twig'),