Rendering Content-Elements¶

Retrieving pre-rendered, translated content-elements¶

Let's imagine you are creating a SPA / frontend-application in VueJS, React or Angular and are using TYPO3 as a backend.

In your application you have various texts and labels, for example in dialog-modals, on the onboarding screen, the privacy policy, imprint and so on. Of course, all of these texts are translated in to multiple languages.

Wouldn't it be great to keep these texts editable in the TYPO3 backend and load them dynamically in the language the user has his browser set to?

The following example illustrates, how easy it is to get pre-rendered and localized content-elements from an endpoint.

Want to render all content-elements of a page?

Then check out how to render a complete column.

Step-by-step¶

Creating the class

After installing the nnrestapi extension, let's start by creating the Content class.

Your Api classes can be located anywhere inside the Classes folder of your extension. We would recommend placing them in a folder named Classes/Api/....

Here is what you need to get started:
```
<?php
namespace My\Extension\Api;

use Nng\Nnrestapi\Annotations as Api;
use Nng\Nnrestapi\Api\AbstractApi;

/**
 * @Api\Endpoint()
 */
class Content extends AbstractApi {
}
```
Defining the GET-method

The idea is to be able to get any content-element by its uid by sending a GET-request to the endpoint:
```
https://www.mysite.com/api/content/{uid}
```
Reminder: If no Routing by custom Routes is defined for the method, the first part of the URL-path after api/ will be interpreted as the controller-name of your endpoint. In this case content automatically will route to methods in your class Content.

If the next part of the URL is an integer. This will automatically be mapped to the request argument $uid and will call the indexAction of your class.

As we want a GET request here, all we need to do is define a method called getIndexAction().

To get the uid, let's use Dependency Injection:
```
<?php
namespace My\Extension\Api;

use Nng\Nnrestapi\Annotations as Api;
use Nng\Nnrestapi\Api\AbstractApi;

/**
 * @Api\Endpoint()
 */
class Content extends AbstractApi
{
   /**
    * @Api\Access("public")
    * @Api\Localize()
    *
    * @param int $uid
    * @return array
    */
   public function getIndexAction( int $uid = null )
   {
      $html = \nn\t3::Content()->render( $uid );
      return ['html'=>$html];
   }
}
```
The two things to pay attention to here are:
```
@Api\Access("public")
```
This says, that anybody can access this endpoint. No authentication required. No need to be logged in. You probably will want to change this.
```
@Api\Localize()
```
Defines, that the nnrestapi will "pay attention" to the requested language and translate the content-element (if a translation exists for it in the backend).
Test it!

Create a content-element in the backend, translate it and then enter the URL in the browser to see the result. Replace 123 in the example with the uid of your content-element in the default language:
```
https://www.mysite.com/api/content/123
```
This should give you a JSON with the rendered content element in your default language. To get the localized version you have 3 possibilities:

1. Send the "Accept-Language" header

Send a Accept-Language header with your request as described in this chapter. The nnrestapi will automatically "listen" to this header and make sure that the data returned will be localized.
```
Accept-Language: en-US
```
2. Use the language path in the URL

Call the endpoint, but add the language prefix to the URL like you would when doing standard requests to TYPO3 pages.
```
https://www.mysite.com/en/api/content/123
```
Getting translations, even with no language path set? Simple explanation: You are currently testing things by entering the URL in the browser. Your browser might automatically be sending an Accept-Language-header, e.g. en-DE. The nnrestapi falls back to the Accept-Language header, if no other language path is set in the URL. This can be changed by removing Accept-Language as a field to check in the TypoScript setup.

3. Use the "L"-parameter in the URL

Last option: add the famous "L"-parameter with the language-uid to the URL. This option was actually removed in one of the last TYPO3 versions - but we are "reintroducing" it because it might make life a little easier:
```
https://www.mysite.com/api/content/123?L=1
```

Tip

Test it in the backend!

Testing the localization can also be done using the "RestApi" backend module: Use the tab "Language" below the input field for the URL to modify the "Accept-Language" header that is sent when making the request.