>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3620865. --> Reported by: [heddn](https://www.drupal.org/user/1463982) Related to !63 >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p><code>_potx_get_plural_form()</code> carries a hardcoded array of about 35 language codes. Every language outside it exports a header of <code>"Plural-Forms: nplurals=INTEGER; plural=EXPRESSION;"</code>, which translators fix by hand. Each missing language becomes its own issue and its own one-line patch:</p> <ul> <li><span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3404056" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3404056</a></span> Catalan (RTBC)</li> <li><span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3525791" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3525791</a></span> Basque (RTBC)</li> <li><span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3525822" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3525822</a></span> and <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3176864" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3176864</a></span> Galician (RTBC, Needs review &mdash; duplicates)</li> <li><span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3427108" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3427108</a></span> pt-pt (RTBC)</li> <li><span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3028920" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3028920</a></span> custom language prefixes such as <code>en-GB</code> (Needs work, Major)</li> </ul> <p>Two defects underneath are not fixed by adding more languages.</p> <p><strong>Regional langcodes cannot match.</strong> The array&rsquo;s only regional key is <code>pt_BR</code>, but Drupal langcodes are lower case and hyphenated (<code>pt-br</code>). That entry has never been reachable, and no regional langcode can be. This is the root cause of <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3427108" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3427108</a></span> and <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3028920" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3028920</a></span>.</p> <p><strong>The two halves of the header disagree.</strong> <code>_potx_get_header()</code> takes <code>nplurals</code> from <code>locale.plural.formula</code>, which only learns a plural count from an imported .po file and otherwise returns 2, while the formula comes from the array. Russian exports as <code>nplurals=2</code> next to a formula returning three positions; Japanese, as 2 next to a one-form formula. This is the <code>INTEGER</code> half of <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3028920" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3028920</a></span>.</p> <p>Core has nothing to delegate to. <code>PoHeader</code> only parses a formula it is given, and <code>PluralFormula</code> only learns formulas at runtime from imported headers. Neither ships per-language data, and <code>PluralFormulaInterface::getFormula()</code> returns an element stack rather than arithmetic (<span class="drupalorg-gitlab-issue-link project-issue-status-info project-issue-status-13"><a href="https://www.drupal.org/project/drupal/issues/2882617" title="Status: Needs work">#2882617: String version of plural formula is not available, exported .po files contain an incorrect default</a></span>).</p> <h3 id="summary-steps-to-reproduce">Steps to reproduce</h3> <ol> <li>Install Drupal and enable potx.</li> <li>Add Catalan and make it the default language.</li> <li>At <code>/admin/config/regional/translate/extract</code>, extract "Template file for Catalan translations" for any directory.</li> <li>The header reads <code>nplurals=INTEGER; plural=EXPRESSION;</code>.</li> </ol> <p>For the second defect, add Russian instead. The header reads <code>nplurals=2</code> beside a three-form formula.</p> <h3 id="summary-proposed-resolution">Proposed resolution</h3> <ul> <li>Add a <code>plural_forms</code> key to <code>potx.settings</code> mapping a langcode to its Gettext formula, shipping the 45 languages the current array covers plus the ones above. Adding a language becomes a YAML edit rather than a patch.</li> <li>Derive <code>nplurals</code> from the formula with <code>PoHeader::parsePluralForms()</code>, the same class that reads the header back on import, instead of storing it alongside where it can drift.</li> <li>Normalise langcodes on both sides of the lookup, so <code>pt_BR</code> and <code>pt-br</code> resolve alike.</li> <li>Fall back through subtags, so <code>en-GB</code> uses <code>en</code> and <code>zh-hant-hk</code> uses <code>zh-hant</code>. Only languages differing from their base need an entry.</li> <li>Report and skip a formula <code>PoHeader</code> cannot parse, or one containing characters that are not Gettext arithmetic. The formula is written into the header verbatim.</li> <li>Ship defaults in <code>config/install/</code> and add an update hook that unions them into an existing <code>potx.settings</code>, so sites keep anything they configured.</li> </ul> <p>Gained: <code>ca</code>, <code>eu</code>, <code>gl</code>, <code>th</code>, <code>zh-hans</code> and <code>zh-hant</code> as entries; <code>pt-pt</code>, <code>es-la</code>, <code>en-GB</code> and every other regional variant through the fallback. <code>pt-br</code> becomes reachable for the first time.</p> <p>Plural forms and the header had no test coverage, so a kernel test is added alongside.</p> <h3 id="summary-remaining-tasks">Remaining tasks</h3> <ul> <li>Review.</li> <li>Renumber the update hook against <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3169135" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3169135</a></span>, which introduces <code>potx.settings</code> separately and also claims <code>potx_update_10201()</code>. Whichever lands second rebases.</li> <li>Close <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3404056" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3404056</a></span>, <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3525791" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3525791</a></span>, <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3525822" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3525822</a></span>, <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3176864" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3176864</a></span>, <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3427108" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3427108</a></span> and <span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/potx/-/work_items/3028920" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/potx/-/work_items/3028920</a></span> once this lands.</li> <li><code>potx_update_10201()</code> has no test of its own; update path testing in contrib needs a database fixture.</li> <li>Follow-up for a settings form, for sites that would rather not edit YAML.</li> </ul> <h3 id="summary-ui-changes">User interface changes</h3> <p>None. Configuration only, via YAML, <code>drush config:set</code> or config import.</p> <h3 id="summary-api-changes">API changes</h3> <p><code>_potx_get_plural_form()</code> returns an array with <code>nplurals</code> and <code>formula</code> keys, or NULL, rather than a formula string. Internal API; <code>_potx_get_header()</code> is its only caller. Adds <code>_potx_normalize_langcode()</code> and <code>_potx_parse_plural_form()</code>.</p> <h3 id="summary-data-model-changes">Data model changes</h3> <p>New <code>potx.settings</code> config object with a <code>plural_forms</code> sequence of formulas keyed by langcode, plus schema. <code>potx_update_10201()</code> adds the defaults to existing sites, unioning so configured languages are kept.</p>