[i18n] Separate .json translation files for themes

pull request TryGhost#8437

- for .hbs templates in content/themes, using translation files:
content/themes/mytheme/assets/translations/mytheme_en.json,
mytheme_es.json, mytheme_en-US.json, etc. (replacing "mytheme" with the
active theme, such as casper, etc.)
- during Ghost's initialization, first default internationalization just
for core briefly until settings for language and theme are available;
then full internationalization for core and theme
- files are read into memory just when needed
- included comments with next changes when language will be in settings
- there is a complementary commit for Casper default theme's PR
TryGhost/Casper#306

core/server/index.js

@@ -39,9 +39,10 @@ function init() {
 
     var ghostServer, parentApp;
 
-    // Initialize Internationalization
+    // Initialize default internationalization, just for core now
+    // (settings for language and theme not yet available here)
     common.i18n.init();
-    debug('I18n done');
+    debug('Default i18n done for core');
     models.init();
     debug('models done');
 
@@ -52,6 +53,11 @@ function init() {
         return settings.init();
     }).then(function () {
         debug('Update settings cache done');
+        // Initialize full internationalization for core and theme
+        // (settings for language and theme available here)
+        return i18n.init();
+    }).then(function () {
+        debug('Full i18n done for core and theme');
         // Initialize the permissions actions and objects
         return permissions.init();
     }).then(function () {

core/server/lib/common/i18n.js

@@ -9,11 +9,20 @@ var supportedLocales = ['en'],
     logging = require('./logging'),
     errors = require('./errors'),
     jp = require('jsonpath'),
+    path = require('path'),
+    settingsCache = require('./settings/cache'),
 
-    // You can choose the current locale here. E.g.: en = English (default), es = Spanish, etc.
-    // The corresponding translation file (en.json, es.json...) should be at core/server/translations/
+    // For now, you can choose the current locale here. E.g.: en = English (default), es = Spanish, en-US = American English, etc.
+    // The corresponding translation files should be at core/server/translations/en.json, es.json, en-US.json... and
+    // content/themes/mytheme/assets/translations/mytheme_en.json, mytheme_es.json, mytheme_en-US.json...
     // TODO: fetch this dynamically based on overall blog settings (`key = "default_locale"`) in the `settings` table
+    // (settings not available here during Ghost's initialization but inside i18n functions, see TODO comments below
+    // and file core/server/index.js)
     currentLocale = 'en',
+    activeTheme,
+    blosCoreDefault,
+    blosCore,
+    blosTheme,
     blos,
     I18n;
 
@@ -30,6 +39,9 @@ I18n = {
         var string = I18n.findString(path),
             msg;
 
+        // TODO: When language will be in settings:
+        // currentLocale = settingsCache.get('default_lang') || 'en';
+
         // If the path returns an array (as in the case with anything that has multiple paragraphs such as emails), then
         // loop through them and return an array of translated/formatted strings. Otherwise, just return the normal
         // translated/formatted string.
@@ -126,15 +138,56 @@ I18n = {
      *  - Polyfill node.js if it does not have Intl support or support for a particular locale
      */
     init: function init() {
-        // read file for current locale and keep its content in memory
-        blos = fs.readFileSync(path.join(__dirname, '..', '..', 'translations', currentLocale + '.json'));
-
-        // if translation file is not valid, you will see an error
-        try {
-            blos = JSON.parse(blos);
-        } catch (err) {
-            blos = undefined;
-            throw err;
+        // TODO: When language will be in settings:
+        // currentLocale = settingsCache.get('default_lang') || 'en';
+
+        activeTheme = settingsCache.get('active_theme') || '';
+
+        // read files for current locale and active theme and keep their content in memory
+        if (activeTheme) {
+            // Initialize full internationalization for core and theme
+            // (settings for language and theme available here)
+            if (blosCore === undefined) {
+                blosCoreDefault = {};
+                blosCore = fs.readFileSync(path.join(__dirname, '..', '..', 'translations', currentLocale + '.json'));
+            }
+            if (blosTheme === undefined) {
+                // Compatibility with both old themes and i18n-capable themes.
+                try {
+                    blosTheme = fs.readFileSync(path.join(__dirname, '..', '..', '..', '..', 'content', 'themes', activeTheme, 'assets', 'translations', activeTheme + '_' + currentLocale + '.json'));
+                } catch (err) {
+                    blosTheme = undefined;
+                    if (err.code === 'ENOENT') {
+                        console.log('File ' + activeTheme + '_' + currentLocale + '.json not found!');
+                    } else {
+                        throw err;
+                    }
+                }
+            }
+            // if translation files are not valid, you will see an error
+            try {
+                if (blosTheme === undefined) {
+                    blos = JSON.parse(blosCore);
+                } else {
+                    blos = _.merge(JSON.parse(blosCore), JSON.parse(blosTheme));
+                }
+            } catch (err) {
+                blos = undefined;
+                throw err;
+            }
+        } else {
+            // Initialize default internationalization, just for core now
+            // (settings for language and theme not yet available here)
+            if (blosCoreDefault === undefined) {
+                blosCoreDefault = fs.readFileSync(path.join(__dirname, '..', '..', 'translations', currentLocale + '.json'));
+            }
+            // if translation file is not valid, you will see an error
+            try {
+                blos = JSON.parse(blosCoreDefault);
+            } catch (err) {
+                blos = undefined;
+                throw err;
+            }
         }
 
         if (global.Intl) {
@@ -164,6 +217,8 @@ I18n = {
      * such as core/server/helpers/date.js and core/server/helpers/t_css.js
      */
     locale: function locale() {
+        // TODO: When language will be in settings:
+        // currentLocale = settingsCache.get('default_lang') || 'en';
         return currentLocale;
     }
 };

core/server/translations/en.json

@@ -611,28 +611,5 @@
         "with the email address": "with the email address",
         "Your email address": "Your email address",
         "You've successfully subscribed to": "You've successfully subscribed to"
-    },
-    "casper": {
-        "A 1-post collection": "A 1-post collection",
-        "A %-post collection": "A %-post collection",
-        "by this author": "by this author",
-        "Close": "Close",
-        "Get the latest posts delivered right to your inbox": "Get the latest posts delivered right to your inbox",
-        "Menu": "Menu",
-        "more posts": "more posts",
-        "No posts": "No posts",
-        "on": "on",
-        "or subscribe": "or subscribe",
-        "Proudly published with {ghostLink}": "Proudly published with {ghostLink}",
-        "Read": "Read",
-        "Scroll Down": "Scroll Down",
-        "Share this post": "Share this post",
-        "Subscribe": "Subscribe",
-        "Subscribe to": "Subscribe to",
-        "via RSS": "via RSS",
-        "with Feedly!": "with Feedly!",
-        "Your email address": "Your email address",
-        "1 post": "1 post",
-        "% posts": "% posts"
     }
 }

core/server/translations/es.json

@@ -590,28 +590,5 @@
         "with the email address": "con el correo electrónico",
         "Your email address": "Tu correo electrónico",
         "You've successfully subscribed to": "Te has suscrito con éxito a"
-    },
-    "casper": {
-        "A 1-post collection": "Una colección de 1 artículo",
-        "A %-post collection": "Una colección de % artículos",
-        "by this author": "de este autor",
-        "Close": "Cerrar",
-        "Get the latest posts delivered right to your inbox": "Recibe los últimos artículos directamente en tu buzón",
-        "Menu": "Menú",
-        "more posts": "más artículos",
-        "No posts": "No hay artículos",
-        "on": "en",
-        "or subscribe": "¡O suscríbete",
-        "Proudly published with {ghostLink}": "Publicado con {ghostLink}",
-        "Read": "Lee",
-        "Scroll Down": "Bajar",
-        "Share this post": "Comparte",
-        "Subscribe": "Suscríbete",
-        "Subscribe to": "Suscríbete a",
-        "via RSS": "por RSS",
-        "with Feedly!": "con Feedly!",
-        "Your email address": "Tu correo electrónico",
-        "1 post": "1 artículo",
-        "% posts": "% artículos"
     }
 }

core/test/unit/server_helpers/t_spec.js

@@ -14,29 +14,33 @@ describe('{{t}} helper', function () {
             should.exist(rendered);
             rendered.string.should.equal(expected);
         });
-        it('returns correct default theme text string', function () {
-            var expected = 'Proudly published with <a href="https://ghost.org">Ghost</a>',
-                rendered = helpers.t.call({}, 'casper', 'Proudly published with \{ghostLink\}', {
-                    hash: {
-                        ghostLink: '<a href="https://ghost.org">Ghost</a>'
-                    }
-                });
-            should.exist(rendered);
-            rendered.string.should.equal(expected);
-        });
+        // Removed for compatibility with both old themes and i18n-capable themes:
+        //
+        // it('returns correct default theme text string', function () {
+        //     var expected = 'Proudly published with <a href="https://ghost.org">Ghost</a>',
+        //         rendered = helpers.t.call({}, 'casper', 'Proudly published with \{ghostLink\}', {
+        //             hash: {
+        //                 ghostLink: '<a href="https://ghost.org">Ghost</a>'
+        //             }
+        //         });
+        //     should.exist(rendered);
+        //     rendered.string.should.equal(expected);
+        // });
     } else {
         it('returns frontend text string translation', function () {
             var rendered = helpers.t.call({}, 'frontend', 'Page', {});
             should.exist(rendered);
         });
-        it('returns default theme text string translation', function () {
-            var rendered = helpers.t.call({}, 'casper', 'Proudly published with \{ghostLink\}', {
-                    hash: {
-                        ghostLink: '<a href="https://ghost.org">Ghost</a>'
-                    }
-                });
-            should.exist(rendered);
-            rendered.string.should.match(/<a href\=\"https\:\/\/ghost\.org\">Ghost<\/a>/);
-        });
+        // Removed for compatibility with both old themes and i18n-capable themes:
+        //
+        // it('returns default theme text string translation', function () {
+        //     var rendered = helpers.t.call({}, 'casper', 'Proudly published with \{ghostLink\}', {
+        //             hash: {
+        //                 ghostLink: '<a href="https://ghost.org">Ghost</a>'
+        //             }
+        //         });
+        //     should.exist(rendered);
+        //     rendered.string.should.match(/<a href\=\"https\:\/\/ghost\.org\">Ghost<\/a>/);
+        // });
     }
 });