unique identifier for the same pages in a multilanguage/site context

Question

I've got always the same problem. If I program a multisite for multilanguage purposes, I cannot find a way to not change the page links in every language. I mean, suppose I've got a page named 'Activity' in the english version. Then got the Italian version, and the same page is called 'Attività'. If I've got a manually-setted link outside the menus, say:

get_page_by_title('Activity')

Then I've got to translate it in the IT theme:

get_page_by_title('Actività')

And so on for all the other languages.

So, is there a way to avoid having to check for all links in every language?

Thank you

Answer 1

For people, as me, that comes to this thread, looking for a solution, pll_get_post() is your function. I think this is the easiest solution for this problem.

    $the_translated_page = get_page_by_title( 'Custom page' );
    $the_translated_page = pll_get_post( $the_translated_page->ID );
    $the_translated_page_URL = get_permalink( $the_translated_page );

I'm pretty sure that this function (pll_get_post) was recently included in the plugin, or at least, it didn't exists in 2013...

Hope it helps!

Answer 2

Translate the title before you query for it:

get_page_by_title( __( 'Activity', 'your_text_domain' ) );

Or store the relationship between posts in a separate table like Multilingual Press does it. Then look up that table for the associated post.

Answer 3

My solution to my problem: custom fields. Basically, you can create a custom field (with the default admin tool) and call it say, "class", or whatever you want. You can then assign it a value that will be the same for all languages of the same page. What is good is that in fact, if you use the default xml export>import tool to copy the page structure in all the languages/sites, the custom field will be retained, so you have to write it only once per page.

That said, I also made 2 raw and small functions and I want to share them.

I use this one instead of is_page(), to set different css and js files:

function has_page_class($page_class){
global $wpdb;
$id = get_queried_object_id();

$check = $wpdb->get_var($wpdb->prepare(
"SELECT COUNT(*)  
FROM $wpdb->postmeta m 
WHERE m.post_id = %d and m.meta_key = 'class' and m.meta_value = %s",
$id, $page_class));

if($check) return true;

return false;
}

And I use this one instead of get_permalink() or get_page_by_title():

function get_link_by_page_class($page_class){
global $wpdb;
    //Since the meta SHOULD be unique once per language I could use get_var.
    //But I keep get_results and take the first found page with that meta for programming reasons.
$pages = $wpdb->get_results($wpdb->prepare( "SELECT post_id FROM $wpdb->postmeta m WHERE m.meta_key = 'class' AND m.meta_value= %s", $page_class));

if($pages && isset($pages[0])){
    $p = $pages[0];
    echo get_permalink($p->post_id);
}
}

By assigning the 'class' custom field to the pages of one language and then using these functions in the theme code, I can duplicate the theme for all languages (or maybe in some cases just use the same..) without worring about switching page names in functions that use them.

Answer 4

UPDATE (polylang plugin):

Here's a revised version of the original function, this time for use with polylang plugin:

//assume polylang as multilingual plugin
function get_link_by_template($template,$lang_slug = null){
    global $wpdb;
    $joins = "";
    $wh = "";

    if($lang_slug){
        $joins = " INNER JOIN $wpdb->term_relationships tr ON meta.post_id = tr.object_id
        INNER JOIN $wpdb->term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id
        INNER JOIN $wpdb->terms t ON tt.term_id = t.term_id ";

        $wh = " AND t.slug = %s";
    }

    $pages = $wpdb->get_results($wpdb->prepare(
        "SELECT post_id
        FROM $wpdb->postmeta meta " . $joins . "
        WHERE meta.meta_key = %s AND meta.meta_value= %s" . $wh,
            '_wp_page_template',
            $template,
            $lang_slug
    ));

    if($pages && isset($pages[0])){
      $p = $pages[0];
      echo get_permalink($p->post_id);
    }

}//get_link_by_template

usage:

//no language
get_link_by_template('contacts.php');

//current language
get_link_by_template('contacts.php',pll_current_language());

//manual language
get_link_by_template('contacts.php','it');

pll_current_language() returns the current language. See polylang codex.

---

OLD (for wpml):

I add another answer, to solve also the problem of linking. I've made another function to use with the 'is_page_template' way:

 //assume wpml as multilingual plugin
function get_link_by_template($template,$check_lang = false){
    global $wpdb;

    //if there's the need of adding lang vars on the URL
    $lang_join_string = (!$check_lang) ? "" : " left join ". $wpdb->prefix ."icl_translations tr on meta.post_id = tr.element_id ";
    $lang_where_string =  (!$check_lang) ? "" : " AND tr.language_code = '" . ICL_LANGUAGE_CODE . "'";

    $pages = $wpdb->get_results($wpdb->prepare(
        "SELECT post_id 
        FROM $wpdb->postmeta meta" . $lang_join_string . "
        WHERE meta.meta_key = '_wp_page_template' AND meta.meta_value= %s" . $lang_where_string, 
    $template));

    if($pages && isset($pages[0])){
        $p = $pages[0];
        echo get_permalink($p->post_id);
    }
}//get_link_by_template

Answer 5

I've found out that another answer could be to just use the is_page_template tag.

Since I'm preatty sure that the NAME of the php template file that needs custom css and/or js will be the same through all the languages (both using the multisite way or things like WPML), I can say

if(is_page_template('that-page.php')) do this..

Simple and fast.