Drupal 8 Module Development

Using the cache metadata

Now that we have looked at the three main cache properties, we need to consider creating render arrays, so let's revisit some of our previous work and apply this in practice as needed.

Quite often you'll see the CacheableMetadata object being used and passed around in Drupal 8 core code. This is simply used to represent cache metadata and also provides some handy methods to apply that metadata to a render array, statically instantiate itself from one, or from a CacheableDependencyInterface object, as well as merge itself with another CacheableMetadata object.

The render array we will look at is inside the HelloWorldSalutation::getSalutationComponent() service and is used to render the salutation message. We are building ...