Flapping lang for multiple instance elements between a localized language and the default language

Root Cause

this.lang resets to the default language ("en") of boundElement at rendering if any of the extended elements has not updated lang property with <html lang>

Reproducible Code

demo/src/clock.js for live-localizer, which is rendered within the polymer template for my-view1.js
- Not reproducible with i18n-element/demo/clock/clock.js

Fix

Skip updating boundElement.lang by this.lang if boundElement.lang has already been synchronized with <html lang>


diff --git a/i18n-core.js b/i18n-core.js
index 9052605..4247339 100644
--- a/i18n-core.js
+++ b/i18n-core.js
@@ -327,7 +327,9 @@ export const i18n = (base) => mixinMethods(I18nControllerCoreMixin, class I18nBa
   // bound element
   let boundElement = this.getBoundElement(name, meta);
   if (boundElement.lang !== this.lang) {

boundElement.lang = this.lang;
if (!(boundElement.observeHtmlLang && boundElement._html.lang === boundElement.lang)) {
boundElement.lang = this.lang;
} } if (boundElement.templateDefaultLang !== this.templateDefaultLang) { boundElement.templateDefaultLang = this.templateDefaultLang; diff --git a/i18n.js b/i18n.js index 89c05bb..5a8b420 100644 --- a/i18n.js +++ b/i18n.js @@ -332,7 +332,9 @@ export const i18n = (base) => mixinMethods(I18nControllerMixin, class I18nBaseEl // bound element let boundElement = this.getBoundElement(name, meta); if (boundElement.lang !== this.lang) {
boundElement.lang = this.lang;
if (!(boundElement.observeHtmlLang && boundElement._html.lang === boundElement.lang)) {
boundElement.lang = this.lang;
} } if (boundElement.templateDefaultLang !== this.templateDefaultLang) { boundElement.templateDefaultLang = this.templateDefaultLang;

Workaround

Explicitly specify lang property or attribute for each item

class ContainerElement extends i18n(HTMLElement) {
render() {
return html`${bind(this)}
  <multiple-element .lang=${this.lang}></multiple-element>
  <multiple-element .lang=${this.lang}></multiple-element>`;
}
...
}

t2ym / i18n-element

Flapping lang for multiple instance elements between a localized language and the default language #92

Root Cause

Reproducible Code

Fix

Workaround