Is it possible or/and how to restrict access to the block on th certain page using route name?

Question

I am trying to restrict access to the block to be accessible only on the route:entity.user.canonical route.

Is it possible to define that on the block edit form?

Answer 1

There is no UI for it, but you can either write your own condition plugin to do that or implement hook_block_access() like this:

function yourmodule_user_block_access(BlockInterface $block, $operation, AccountInterface $account) {

  $hidden_blocks = ['yourtheme_block_id'];
  $hidden_routes = ['entity.user.canonical'];

  if ($operation == 'view' && in_array($block->id(), $hidden_blocks) && in_array(\Drupal::routeMatch()->getRouteName(), $hidden_routes)) {
    return AccessResult::forbidden();
  }
}