I have a custom entity, with a controller class that extends
EntityViewController much like the node module does in core. The
view method in this class returns a render array
$build and it is called by the router for my entity.
I would now like to attach some more content to this render array, specifically some articles from another site. I have a class of my own that I am able to implement like this inside the
$client = new FrontpageArticlesBuilder(); $articles = $client->toRenderArray();
$articles is a render array. I would like to know how I can append this render array to my existing
$build render array returned by
view() method in my controller.