lbineau

Ok I found how to do it, you have to call admin-ajax.php?lang=code.
So I have to wait pll_current_language() to be available with pll_language_defined action.
Then the ajax function was called with the right language.

function.php

add_action('pll_language_defined', 'on_language_defined');
// Set some JS variables
function on_language_defined()
{
    if ($GLOBALS['pagenow'] != 'wp-login.php' && !is_admin()) {

        // write variables into DOM
        global $wp_query;
        wp_localize_script( 'ajax-pagination', 'ajaxpagination', array(
            'ajaxurl' => admin_url( 'admin-ajax.php' ) . '?lang='.pll_current_language(), // the language parameters is usefull to call ajax function with language set
            'query_vars' => json_encode( $wp_query->query )
        ));

    }
}

Same here with a fresh install and last versions of WordPress SEO and Polylang.
I have also the following fatal error : ( ! ) Fatal error: Call to undefined method stdClass::canonical() in ***\wp-content\plugins\wordpress-seo\inc\wpseo-non-ajax-functions.php on line 227

Same here with a fresh install and last versions of WordPress SEO and Polylang.
I have also the following fatal error : ( ! ) Fatal error: Call to undefined method stdClass::canonical() in ***\wp-content\plugins\wordpress-seo\inc\wpseo-non-ajax-functions.php on line 227

I don’t think so. I never actived it on my own. How can I check that ?

Yep I am on version 3.4.2