Getting language from path

I was looking into a similar solution, just a simple query override. Here is my attempt w/the information you’ve provided Chouby. The majority of this code is just checking the query against known supported languages before making the override.

This doesn’t work 100%, 100% of the time – but it get’s pretty close.

The goal would be for anyone, even an FB crawler to specify a locale when linking to a page like https://black-buddha.com/?locale=zh_TW or https://black-buddha.com/zh_tw/watch/mott32-2/?fb_locale=en_US. I’ve been seeing a lot of log entries from facebook.com/externalhit_uatext.php lately and I wonder if this might be helpful.

Either way, I just want to solve this translation override for the login form, so here is a start.

Cheers

/* ==================================================
* OVERRIDE CURRENT PLL LANGUAGE
* ==================================================*/

/**
 * HiJack the pll_language_defined action and override the current language.
 * @param string $slug
 * @param PLL_Language $curlang
 * @example https://black-buddha.com/?l=zh_TW
 * @example https://black-buddha.com/zh_tw/city/臺北/?locale=en_US
 * @example https://black-buddha.com/watch/flask/?fb_locale=zh_TW
 * @example https://black-buddha.com/?lang=zh_TW
 */
function ___pll_language_defined ( $slug, $curlang ) {
	static $override_language = FALSE;
	global $polylang;

	if ( ! $polylang ) {
		return;
	}

	if ( ! $override_language ) {
		$reqs = array( $_GET, $_POST );
		$params = array( 'lang', 'locale', 'l' , 'fb_locale' );

		foreach ( $reqs as $req ) {
			if ( $override_language ) break;

			foreach ( $params as $param ) {
				if ( $override_language ) break;

				if ( ! empty( $req[ $param ] ) ) {
					$override_language = sanitize_key( $req [ $param ] );
					break;
				}
			}
		}
	}

	if ( $override_language ) {

		// validate against known languages
		$supported_languages = $polylang->model->get_languages_list ( );
		foreach ($supported_languages as $lang) {
			if ( FALSE != preg_match( "/($override_language)/i", $lang->locale )) {
				$override_language = $lang->slug;
				break;
			}
		}

		if ( ! $override_language) {
			error_log ( 'FAILED to find language support for ' . $override_language );
			$override_language = FALSE;
			return;
		}

		// try to get the language
		$nLanguage = $polylang->model->get_language( $override_language );
		if ( $nLanguage ) {
			$polylang->curlang = $nLanguage;
			$GLOBALS [ 'text_direction' ] = $polylang->curlang->is_rtl ? 'rtl' : 'ltr';
			stop_checking_language_code_in_url ( );

			// NOTE: setcookie has been called already
			// (PLL_Choose_Lang)$this->maybe_setcookie();
		} else {
			error_log ( 'FAILED to change language to ' . $override_language );
			$override_language = FALSE;
		}
	}
}

// NOTE: do_action called from wp-content/plugins/polylang/frontend/choose-lang.php
add_action('pll_language_defined', '___pll_language_defined', 0, 2);

function stop_checking_language_code_in_url ( ) {
	global $polylang;
	if ( $polylang ) {
		remove_action('wp', array ( $polylang->choose_lang, 'check_language_code_in_url' ));
	}
}
// WARNING: Stops working well when you remove the code in url check...
// if(did_action('plugins_loaded')) stop_checking_language_code_in_url();
// add_action( 'plugins_loaded', 'stop_checking_language_code_in_url', 10 );