client,server: Add first day of week option

src/public/app/widgets/buttons/calendar.js

@@ -206,4 +206,11 @@ export default class CalendarWidget extends RightDropdownButtonWidget {
         this.$monthSelect.val(this.date.getMonth());
         this.$yearSelect.val(this.date.getFullYear());
     }
+
+    async entitiesReloadedEvent({loadResults}) {
+        if (loadResults.getOptionNames().includes("firstDayOfWeek")) {
+            this.init();
+        }
+    }
+
 }

src/public/app/widgets/type_widgets/options/appearance/i18n.js

@@ -12,6 +12,14 @@ const TPL = `
             <label>${t("i18n.language")}</label>
             <select class="locale-select form-control"></select>
         </div>
+
+        <div class="col-6">
+            <label>First day of the week</label>
+            <select class="first-day-of-week-select form-control">
+                <option value="0">Sunday</option>
+                <option value="1">Monday</option>
+            </select>
+        </div>
     </div>
 </div>
 `;
@@ -19,12 +27,18 @@ const TPL = `
 export default class LocalizationOptions extends OptionsWidget {
     doRender() {
         this.$widget = $(TPL);
+        
         this.$localeSelect = this.$widget.find(".locale-select");
         this.$localeSelect.on("change", async() => {
             const newLocale = this.$localeSelect.val();
             await server.put(`options/locale/${newLocale}`);
             utils.reloadFrontendApp("locale change");
         });
+
+        this.$firstDayOfWeek = this.$widget.find(".first-day-of-week-select");
+        this.$firstDayOfWeek.on("change", () => {
+            this.updateOption("firstDayOfWeek", this.$firstDayOfWeek.val());
+        });
     }
 
     async optionsLoaded(options) {
@@ -38,5 +52,6 @@ export default class LocalizationOptions extends OptionsWidget {
         }
 
         this.$localeSelect.val(options.locale);
+        this.$firstDayOfWeek.val(options.firstDayOfWeek);
     }
 }

src/routes/api/options.ts

@@ -59,7 +59,8 @@ const ALLOWED_OPTIONS = new Set([
     'customSearchEngineUrl',
     'promotedAttributesOpenInRibbon',
     'editedNotesOpenInRibbon',
-    'locale'
+    'locale',
+    'firstDayOfWeek'
 ]);
 
 function getOptions() {

src/services/options_init.ts

@@ -95,7 +95,10 @@ const defaultOptions: DefaultOption[] = [
     { name: 'customSearchEngineUrl', value: 'https://duckduckgo.com/?q={keyword}', isSynced: true },
     { name: 'promotedAttributesOpenInRibbon', value: 'true', isSynced: true },
     { name: 'editedNotesOpenInRibbon', value: 'true', isSynced: true },
-    { name: 'locale', value: 'en', isSynced: true }
+
+    // Internationalization
+    { name: 'locale', value: 'en', isSynced: true },
+    { name: 'firstDayOfWeek', value: '1', isSynced: true }
 ];
 
 function initStartupOptions() {