Preprocess language switcher block

Question

I'm trying to modify the output of the language switcher block to make the output more inline with other menu styles on my site. However, I can't figure out how to modify the output.

I'm attempting to use the following:

function my_module_preprocess_block(&$variables) {
  var_dump($variables['elements']['#id'];
}

This gets every block on the page except for the language switcher.

How can I preprocess or modify this?

Answer 1

We added a filter to drop the languages that did not have translations from the language switcher. Here's the code from that:

/**
 * Implements hook_block_view_BASE_BLOCK_ID_alter().
 */
function mymodule_block_view_language_block_alter(array &$build, BlockPluginInterface $block) {
  $build['#pre_render'][] = '_mymodule_language_block_prerender';
}

FYI - Used pre_render because I was removing links from the [content][[#links] element.