Add i18n support

Author: saxxi

README.md

@@ -136,6 +136,50 @@ Frappe Gantt exposes a few helpful methods for you to interact with the chart:
 | `.scroll_current` | Scrolls to the current date | No parameters. |
 | `.update_task` | Re-renders a specific task bar alone | `task_id` - id of task and `new_details` - object containing the task properties to be updated. |
 
+## Internationalization (i18n)
+
+The Gantt chart supports multiple languages. By default, it's in English, but you can easily switch to other languages:
+
+### Basic usage
+
+```javascript
+import Gantt from 'frappe-gantt';
+
+// Create Gantt chart with English (default)
+const gantt = new Gantt('#gantt', tasks);
+```
+
+### Using a specific language
+
+```javascript
+import Gantt from 'frappe-gantt';
+
+const gantt = new Gantt('#gantt', tasks, {
+  language: 'it', // or 'it-IT'
+});
+```
+
+### Adding custom translations
+
+You can also create your own translations:
+
+```javascript
+import Gantt from 'frappe-gantt';
+
+const myEoLocale = {
+  Mode: 'Modo',
+  Today: 'Hodiaŭ',
+  Year: 'Jaro',
+  // ...
+};
+
+const gantt = new Gantt('#gantt', tasks, {
+  language: 'eo',
+  locales: {
+    'eo': myEoLocale,
+  },
+});
+
 ## Development Setup
 If you want to contribute enhancements or fixes:
 

src/defaults.js

@@ -1,4 +1,5 @@
 import date_utils from './date_utils';
+import { gettext } from './i18n';
 
 function getDecade(d) {
     const year = d.getFullYear();
@@ -130,19 +131,24 @@ const DEFAULT_OPTIONS = {
         if (ctx.task.description) ctx.set_subtitle(ctx.task.description);
         else ctx.set_subtitle('');
 
+        const lang = ctx.chart.options.language;
         const start_date = date_utils.format(
             ctx.task._start,
             'MMM D',
-            ctx.chart.options.language,
+            lang
         );
         const end_date = date_utils.format(
             date_utils.add(ctx.task._end, -1, 'second'),
             'MMM D',
-            ctx.chart.options.language,
+            lang
         );
 
+        const excluded_text = ctx.task.ignored_duration
+            ? ` + ${ctx.task.ignored_duration} ${gettext('excluded', lang)}`
+            : '';
+
         ctx.set_details(
-            `${start_date} - ${end_date} (${ctx.task.actual_duration} days${ctx.task.ignored_duration ? ' + ' + ctx.task.ignored_duration + ' excluded' : ''})<br/>Progress: ${Math.floor(ctx.task.progress * 100) / 100}%`,
+            `${gettext('Dates', lang)}: ${start_date} - ${end_date} (${ctx.task.actual_duration} ${gettext(ctx.task.actual_duration === 1 ? 'day' : 'days', lang)}${excluded_text})<br/>${gettext('Progress', lang)}: ${Math.floor(ctx.task.progress * 100) / 100}%`
         );
     },
     popup_on: 'click',

src/i18n.js

@@ -0,0 +1,109 @@
+// Import all locale files directly
+import en_US from './locales/en-US.json';
+import it_IT from './locales/it-IT.json';
+import fr_FR from './locales/fr-FR.json';
+import es_ES from './locales/es-ES.json';
+import de_DE from './locales/de-DE.json';
+
+// Static map of all available locales
+const locales = {
+  'en': en_US,
+  'en-US': en_US,
+  'it': it_IT,
+  'it-IT': it_IT,
+  'fr': fr_FR,
+  'fr-FR': fr_FR,
+  'es': es_ES,
+  'es-ES': es_ES,
+  'de': de_DE,
+  'de-DE': de_DE
+};
+
+/**
+ * Add custom locales to the available locales
+ * @param {Object} customLocales - Object containing custom locale translations
+ */
+export function addLocales(customLocales) {
+  if (!customLocales) return;
+
+  // Merge custom locales with existing ones
+  Object.keys(customLocales).forEach(langCode => {
+    locales[langCode] = customLocales[langCode];
+  });
+}
+
+/**
+ * Get a translation for a key in the specified language
+ * @param {string} key - The translation key
+ * @param {string} lang - The language code (defaults to 'en')
+ * @param {Object} params - Parameters to replace in the translation
+ * @returns {string} The translated text or the key if not found
+ */
+export function translate(key, lang = 'en', params = {}) {
+  // Get the appropriate locale or fall back to English
+  const langCode = normalizeLangCode(lang);
+  const locale = locales[langCode] || locales['en'];
+
+  if (!locale) {
+    return key;
+  }
+
+  let text = locale[key] || key;
+
+  // Replace any parameters in the text
+  if (params && Object.keys(params).length > 0) {
+    Object.keys(params).forEach(param => {
+      text = text.replace(new RegExp(`{${param}}`, 'g'), params[param]);
+    });
+  }
+
+  return text;
+}
+
+/**
+ * Alias for translate function for backward compatibility
+ */
+export function gettext(key, lang, params) {
+  return translate(key, lang, params);
+}
+
+/**
+ * Normalize language code to find the most appropriate match
+ * @param {string} langCode - The language code to normalize
+ * @returns {string} The normalized language code
+ */
+function normalizeLangCode(langCode) {
+  if (!langCode) return 'en';
+
+  // First check exact match
+  if (locales[langCode]) return langCode;
+
+  // Check language part only (e.g., 'en' from 'en-US')
+  const mainLang = langCode.split('-')[0];
+  if (locales[mainLang]) return mainLang;
+
+  // Check for any variant of the language
+  const allKeys = Object.keys(locales);
+  for (let i = 0; i < allKeys.length; i++) {
+    if (allKeys[i].startsWith(mainLang + '-')) {
+      return allKeys[i];
+    }
+  }
+
+  return 'en';
+}
+
+/**
+ * Get all available languages
+ * @returns {Object} An object with language codes as keys
+ */
+export function getAvailableLanguages() {
+  return Object.keys(locales);
+}
+
+export default {
+  translate,
+  gettext,
+  getAvailableLanguages,
+  addLocales
+};

src/index.js

@@ -1,4 +1,5 @@
 import date_utils from './date_utils';
+import { gettext, addLocales } from './i18n';
 import { $, createSVG } from './svg_utils';
 
 import Arrow from './arrow';
@@ -13,6 +14,9 @@ export default class Gantt {
     constructor(wrapper, tasks, options) {
         this.setup_wrapper(wrapper);
         this.setup_options(options);
+        if (options.locales) {
+            addLocales(options.locales);
+        }
         this.setup_tasks(tasks);
         this.change_view_mode();
         this.bind_events();
@@ -26,7 +30,7 @@ export default class Gantt {
             let el = document.querySelector(element);
             if (!el) {
                 throw new ReferenceError(
-                    `CSS selector "${element}" could not be found in DOM`,
+                    `CSS selector "${element}" could not be found in DOM`
                 );
             }
             element = el;
@@ -41,7 +45,7 @@ export default class Gantt {
         } else {
             throw new TypeError(
                 'Frappe Gantt only supports usage of a string CSS selector,' +
-                    " HTML DOM element or SVG DOM element for the 'element' parameter",
+                    " HTML DOM element or SVG DOM element for the 'element' parameter"
             );
         }
 
@@ -124,7 +128,7 @@ export default class Gantt {
             .map((task, i) => {
                 if (!task.start) {
                     console.error(
-                        `task "${task.id}" doesn't have a start date`,
+                        gettext('task_no_start_date', this.options.language, { id: task.id || '' })
                     );
                     return false;
                 }
@@ -141,23 +145,25 @@ export default class Gantt {
                     });
                 }
                 if (!task.end) {
-                    console.error(`task "${task.id}" doesn't have an end date`);
+                    console.error(
+                        gettext('task_no_end_date', this.options.language, { id: task.id || '' })
+                    );
                     return false;
                 }
                 task._end = date_utils.parse(task.end);
 
                 let diff = date_utils.diff(task._end, task._start, 'year');
                 if (diff < 0) {
                     console.error(
-                        `start of task can't be after end of task: in task "${task.id}"`,
+                        gettext('task_start_after_end', this.options.language, { id: task.id || '' })
                     );
                     return false;
                 }
 
                 // make task invalid if duration too large
                 if (date_utils.diff(task._end, task._start, 'year') > 10) {
                     console.error(
-                        `the duration of task "${task.id}" is too long (above ten years)`,
+                        gettext('task_duration_too_long', this.options.language, { id: task.id || '' })
                     );
                     return false;
                 }
@@ -476,13 +482,13 @@ export default class Gantt {
             const $el = document.createElement('option');
             $el.selected = true;
             $el.disabled = true;
-            $el.textContent = 'Mode';
+            $el.textContent = gettext('Mode', this.options.language);
             $select.appendChild($el);
 
             for (const mode of this.options.view_modes) {
                 const $option = document.createElement('option');
                 $option.value = mode.name;
-                $option.textContent = mode.name;
+                $option.textContent = gettext(mode.name, this.options.language);
                 if (mode.name === this.config.view_mode.name)
                     $option.selected = true;
                 $select.appendChild($option);
@@ -501,7 +507,7 @@ export default class Gantt {
         if (this.options.today_button) {
             let $today_button = document.createElement('button');
             $today_button.classList.add('today-button');
-            $today_button.textContent = 'Today';
+            $today_button.textContent = gettext('Today', this.options.language);
             $today_button.onclick = this.scroll_current.bind(this);
             this.$side_header.prepend($today_button);
             this.$today_button = $today_button;

src/locales/de-DE.json

@@ -0,0 +1,31 @@
+{
+  "Mode": "Modus",
+  "Today": "Heute",
+  "Year": "Jahr",
+  "Month": "Monat",
+  "Week": "Woche",
+  "Day": "Tag",
+  "Hour": "Stunde",
+  "Quarter Day": "Viertel Tag",
+  "Half Day": "Halber Tag",
+  "year": "Jahr",
+  "years": "Jahre",
+  "month": "Monat",
+  "months": "Monate",
+  "day": "Tag",
+  "days": "Tage",
+  "hour": "Stunde",
+  "hours": "Stunden",
+  "minute": "Minute",
+  "minutes": "Minuten",
+  "second": "Sekunde",
+  "seconds": "Sekunden",
+  "Progress": "Fortschritt",
+  "Duration": "Dauer",
+  "Dates": "Termine",
+  "excluded": "ausgeschlossen",
+  "task_no_start_date": "Aufgabe \"{id}\" hat kein Startdatum",
+  "task_no_end_date": "Aufgabe \"{id}\" hat kein Enddatum",
+  "task_start_after_end": "Der Start der Aufgabe kann nicht nach dem Ende der Aufgabe liegen: in Aufgabe \"{id}\"",
+  "task_duration_too_long": "Die Dauer der Aufgabe \"{id}\" ist zu lang (über zehn Jahre)"
+}

src/locales/en-UK.json

@@ -0,0 +1,31 @@
+{
+  "Mode": "Mode",
+  "Today": "Today",
+  "Year": "Year",
+  "Month": "Month",
+  "Week": "Week",
+  "Day": "Day",
+  "Hour": "Hour",
+  "Quarter Day": "Quarter Day",
+  "Half Day": "Half Day",
+  "year": "year",
+  "years": "years",
+  "month": "month",
+  "months": "months",
+  "day": "day",
+  "days": "days",
+  "hour": "hour",
+  "hours": "hours",
+  "minute": "minute",
+  "minutes": "minutes",
+  "second": "second",
+  "seconds": "seconds",
+  "Progress": "Progress",
+  "Duration": "Duration",
+  "Dates": "Dates",
+  "excluded": "excluded",
+  "task_no_start_date": "task \"{id}\" doesn't have a start date",
+  "task_no_end_date": "task \"{id}\" doesn't have an end date",
+  "task_start_after_end": "start of task can't be after end of task: in task \"{id}\"",
+  "task_duration_too_long": "the duration of task \"{id}\" is too long (above ten years)"
+}

src/locales/en-US.json

@@ -0,0 +1,31 @@
+{
+  "Mode": "Mode",
+  "Today": "Today",
+  "Year": "Year",
+  "Month": "Month",
+  "Week": "Week",
+  "Day": "Day",
+  "Hour": "Hour",
+  "Quarter Day": "Quarter Day",
+  "Half Day": "Half Day",
+  "year": "year",
+  "years": "years",
+  "month": "month",
+  "months": "months",
+  "day": "day",
+  "days": "days",
+  "hour": "hour",
+  "hours": "hours",
+  "minute": "minute",
+  "minutes": "minutes",
+  "second": "second",
+  "seconds": "seconds",
+  "Progress": "Progress",
+  "Duration": "Duration",
+  "Dates": "Dates",
+  "excluded": "excluded",
+  "task_no_start_date": "task \"{id}\" doesn't have a start date",
+  "task_no_end_date": "task \"{id}\" doesn't have an end date",
+  "task_start_after_end": "start of task can't be after end of task: in task \"{id}\"",
+  "task_duration_too_long": "the duration of task \"{id}\" is too long (above ten years)"
+}