Disable cache a custom block for anonymous user

Question

I have a custom block, it displays in every pages with dynamic data calculates in every refresh, How can I disable cache for this block for anonymous users?

I try with:

public function build() {
  return [
    '#markup' => time(),
    '#cache' => [
      'max-age' => 0,
    ],
  ];
}

It won't work.

Edit: I don't want to disable the cache for the entire page, I just need a specific block not to be cache.

Answer 1

If you want to completely disable caching for the block, use this function in your block class:

  public function getCacheMaxAge() {
    return 0;
  }

I've never found in the documentation why

'#cache' => [
      'max-age' => 0,
    ],

doesn't work with blocks but, like you discovered, it doesn't seem to.