Programmatic blocks
The demo website has two blocks defined by modules: one that renders a random quote and one that renders the weather forecast of the next hour for the origin location of a trip.
Blocks are defined as plugins and must follow a set of rules to be available on the frontend, but in the end, a block will return a render array exactly as a controller does.
Both blocks are already available in the alps_quote and alps_weather modules. The weather forecast one, for example, returns this render array:
$build['content'] = [
'#theme' => 'alps_weather_forecast_single',
'#forecast' => $forecast['list'][0],
'#city' => $city,
'#units' => $this->config
->get('alps_weather.settings')->get('units'),
'#cache' => [
'max-age' => 10800...