I’m making a new language selector field type which creates a <select> field from all languages present in a given WPML instance. It’s based on this:
https://www.advancedcustomfields.com/resources/creating-a-new-field-type/.
I was able to follow the instructions fairly well: created the field type, populated it with all the language data from WPML, and made the <select> field appear when editing posts. But I can’t save the selected value to the database.
There’s probably something very basic missing here, but I can’t figure out what it is. Below is what I wrote in the files which in the starter kit is called acf-FIELD_NAME-v5.php. (The part about constructing the array of languages, it works fine. Please just assume that this returns a run-of-the-mill PHP array.)
<?php
if( ! defined( 'ABSPATH' ) ) exit;
if( !class_exists('acf_field_wpml_languages') ) :
class acf_field_wpml_languages extends acf_field {
function __construct( $settings ) {
$this->name = 'wpml_languages';
$this->label = __('WPML Languages', 'acf-wpml_languages');
$this->category = 'choice';
$this->settings = $settings;
parent::__construct();
}
function render_field( $field ) {
global $wpdb;
function get_all_langs_names( $lang, $wpdb ) {
$lang_data = array();
$languages = $wpdb -> get_results(
$wpdb -> prepare( "
SELECT code, english_name, active, tag, name
FROM {$wpdb -> prefix}icl_languages lang
INNER JOIN {$wpdb -> prefix}icl_languages_translations trans
ON lang.code = trans.language_code
AND trans.display_language_code=%s",
$lang )
);
foreach( $languages as $l ) {
$lang_data[$l -> code] = array(
'english_name' => $l -> english_name,
'active' => $l -> active,
'tag' => $l -> tag,
'name' => $l -> name,
);
}
return $lang_data;
}
// get language tag of current site locale...
$code = ICL_LANGUAGE_CODE;
$lang_tag = $wpdb -> get_var("
SELECT tag
FROM {$wpdb -> prefix}icl_languages
WHERE code='{$code}'"
);
// ... and then get language names associated with that tag
$languages = get_all_langs_names( $lang_tag, $wpdb );
// sort language array alphabetically, or however current language orders words
function sort_languages( $a, $b ) {
return strcmp( $a['name'], $b['name'] );
}
usort( $languages, 'sort_languages' );
?>
<select>
<?php
foreach ($languages as $language) {
?><option value=<?php echo '"' . $language['tag'] . '"'; ?>><?php echo $language['name']; ?></option><?php
}
?>
</select>
<?php
}
}
new acf_field_wpml_languages( $this->settings );
endif;
?>
