Set GeneratePress logos based on Polylang current language

generatepress_polylang_logo.php

/**
 * Set GeneratePress site logo based on Polylang current language 
 *
 * This example function allows for the default logo to be set by the English choice, and supports
 * Polish, Dutch and German language-specific logos
 */
if ( ! function_exists( 'generate_construct_logo' ) || ! function_exists( 'pll_current_language' ) ) {
	// Change logo depending on the language
  	// An improvemnt to this would be to not set the array of logos, but check for a logo/language match
	function mattrad_default_logo( $url ) {
		$current_lang = pll_current_language();
		$assets_url = get_stylesheet_directory_uri() . '/assets/images/';
		$url = $assets_url . 'logo-en.png';

		if ( $current_lang !== pll_default_language() ) {
			$logos = [
				'pl' => 'logo-pl.png',
				'nl' => 'logo-nl.png',
				'de' => 'logo-de.png',
			];
			if ( isset( $logos[ $current_lang ] ) ) {
				$url = $assets_url . $logos[ $current_lang ];
			}
		}
		return esc_url( $url );
	}
	add_filter( 'generate_logo', 'mattrad_default_logo' );

  	// Set the logo's width and height
  	// Otherwise, these are not set unless there's an image set in Customizer
	function mattrad_default_logo_attrs( $attr ) {
		$attr['width']  = '212';
		$attr['height'] = '150';
		return $attr;
	}
	add_filter( 'generate_logo_attributes', 'mattrad_default_logo_attrs' );
}