feat: Add og:locale support & fix i18n.seo component option

This apply changes from PR #75 to add support for og:locale meta tags and fixes an issue where SEO
plugin would be unable to access page-specific options

Author: paulgv

src/plugins/seo.js

@@ -3,45 +3,60 @@ import Vue from 'vue'
 Vue.mixin({
   head () {
     if (
-      this.$i18n &&
-      this.$i18n.locales &&
-      this.i18n !== false &&
-      (typeof this.i18n === 'undefined' || this.i18n.seo !== false) &&
-      this._hasMetaInfo
+      !this._hasMetaInfo ||
+      !this.$i18n ||
+      !this.$i18n.locales ||
+      this.$options.i18n === false ||
+      (this.$options.i18n && this.$options.i18n.seo === false)
     ) {
-      const LOCALE_CODE_KEY = '<%= options.LOCALE_CODE_KEY %>'
-      const LOCALE_ISO_KEY = '<%= options.LOCALE_ISO_KEY %>'
+      return {};
+    }
+    const LOCALE_CODE_KEY = '<%= options.LOCALE_CODE_KEY %>'
+    const LOCALE_ISO_KEY = '<%= options.LOCALE_ISO_KEY %>'
 
-      // Prepare html lang attribute
-      const currentLocaleData = this.$i18n.locales.find(l => l[LOCALE_CODE_KEY] === this.$i18n.locale)
-      const htmlAttrs = {}
-      if (currentLocaleData && currentLocaleData[LOCALE_ISO_KEY]) {
-        htmlAttrs.lang = currentLocaleData[LOCALE_ISO_KEY]
-      }
+    // Prepare html lang attribute
+    const currentLocaleData = this.$i18n.locales.find(l => l[LOCALE_CODE_KEY] === this.$i18n.locale)
+    const htmlAttrs = {}
+    if (currentLocaleData && currentLocaleData[LOCALE_ISO_KEY]) {
+      htmlAttrs.lang = currentLocaleData[LOCALE_ISO_KEY]
+    }
 
-      // hreflang tags
-      const link = this.$i18n.locales
-        .map(locale => {
-          if (locale[LOCALE_ISO_KEY]) {
-            return {
-              hid: 'alternate-hreflang-' + locale[LOCALE_ISO_KEY],
-              rel: 'alternate',
-              href: this.switchLocalePath(locale.code),
-              hreflang: locale[LOCALE_ISO_KEY]
-            }
-          } else {
-            console.warn('[<%= options.MODULE_NAME %>] Locale ISO code is required to generate alternate link')
-            return null
+    // hreflang tags
+    const link = this.$i18n.locales
+      .map(locale => {
+        if (locale[LOCALE_ISO_KEY]) {
+          return {
+            hid: 'alternate-hreflang-' + locale[LOCALE_ISO_KEY],
+            rel: 'alternate',
+            href: this.switchLocalePath(locale.code),
+            hreflang: locale[LOCALE_ISO_KEY]
           }
-        })
-      .filter(item => !!item)
+        } else {
+          console.warn('[<%= options.MODULE_NAME %>] Locale ISO code is required to generate alternate link')
+          return null
+        }
+      })
+    .filter(item => !!item)
+
+    // og:locale meta
+    const meta = [
+      // Replace dash with underscore as defined in spec: language_TERRITORY
+      { hid: 'og:locale', name: 'og:locale', property: 'og:locale', content: currentLocaleData[LOCALE_ISO_KEY].replace(/-/g, '_') },
+      ...this.$i18n.locales
+        .filter(l => l[LOCALE_ISO_KEY] !== currentLocaleData[LOCALE_ISO_KEY])
+        .map(locale => ({
+          hid: 'og:locale:alternate-' + locale[LOCALE_ISO_KEY],
+          name: 'og:locale:alternate',
+          property: 'og:locale:alternate',
+          content: locale[LOCALE_ISO_KEY].replace(/-/g, '_')
+        }))
+    ]
 
-      return {
-        htmlAttrs,
-        link
-      }
+    return {
+      htmlAttrs,
+      link,
+      meta
     }
-    return {}
   }
 })