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Multilingual & Translations

Alfa Commerce stores translatable content (product names, aliases, descriptions, meta) in per-language auxiliary tables, not in the main entity table.

Data model​

For every translatable entity there is one aux table per installed content language, named #__alfa_<entity>_<langtag>, sharing the parent's id:

#__alfa_items            (structural columns only: id, sku, stock, prices…)
#__alfa_items_en_gb      (id_item, name, alias, short_desc, meta_title, …)
#__alfa_items_el_gr      (id_item, name, alias, short_desc, meta_title, …)

The main table keeps only non-translatable columns. (Joomla's Table::bind() ignores keys with no matching column, so passing translatable keys in the main $data is harmless.) These tables are created automatically — lazily on first save, or up-front by ensureLangSchema() (the installer and the admin Resync languages tool call it; the system/alfasync plugin calls it when you add a new content language).

How a translatable field flows​

  • Form fields use the fieldName_langCode convention (name_en_gb, alias_el_gr, …) — generated by the MultilingualText field type.
  • Save → MultilingualHelper::saveMultilingualData() splits the flat keys per language and upserts a row into each #__alfa_<entity>_<langtag> table inside one transaction (missing tables/columns are created on the fly).
  • Read into the edit form → bindMultilingualToItem($item, $id, $primaryColumn, $table) in the model's getItem().
  • List queries → addMultilingualJoinToQuery() LEFT-JOINs the current (and default) language table and selects each field via COALESCE(NULLIF(current), NULLIF(default), '') — records without a translation still appear, and the value is read only from language tables.
  • Related entities → addRelatedIdsToQuery() adds correlated GROUP_CONCAT subqueries (no outer GROUP BY, so pagination totals stay correct), then loadRelated() batch-loads the translated related records after pagination.

Aliases​

The alias is fully translatable — each language keeps its own URL slug in its language table, and there is no alias column on the main table (and no fallback to it). Blank aliases are generated from the name, sanitised, and made unique per language, appending -2, -3, … on collision. Uniqueness scope is configurable (aliasUniqueScope): e.g. a category alias is unique within its parent_id, while an item alias is globally unique (items belong to many categories and need an unambiguous site-wide slug).

For language-switch / association links, getTranslatedValue($id, $table, $primaryColumn, 'alias', $langTag) returns a single field in a specific language, so a &lang=xx URL emits that language's alias.

Kept in sync​

The system/alfasync plugin is the runtime bridge that mirrors Joomla users/usergroups into the Alfa shadow tables and, on adding a new content language, runs ensureLangSchema() so the new #__alfa_<entity>_<langtag> tables exist immediately. Keep it enabled — without it, a newly added language has nowhere to store its translations, and new/edited Joomla users won't be mirrored into #__alfa_users.

Reference: administrator/src/Helper/MultilingualHelper.php.