fix(module:date-picker): support changing language at runtime

components/date-picker/abstract-picker.component.ts

@@ -2,13 +2,16 @@ import {
   EventEmitter,
   Input,
   OnChanges,
+  OnDestroy,
   OnInit,
   Output,
   SimpleChanges,
   ViewChild
 } from '@angular/core';
 import { ControlValueAccessor } from '@angular/forms';
 
+import { Subject } from 'rxjs';
+import { takeUntil } from 'rxjs/operators';
 import { InputBoolean } from '../core/util/convert';
 import { NzDatePickerI18nInterface } from '../i18n/nz-i18n.interface';
 import { NzI18nService } from '../i18n/nz-i18n.service';
@@ -20,7 +23,7 @@ const POPUP_STYLE_PATCH = { 'position': 'relative' }; // Aim to override antd's
 /**
  * The base picker for all common APIs
  */
-export abstract class AbstractPickerComponent implements OnInit, OnChanges, ControlValueAccessor {
+export abstract class AbstractPickerComponent implements OnInit, OnChanges, OnDestroy, ControlValueAccessor {
   // --- Common API
   @Input() @InputBoolean() nzAllowClear: boolean = true;
   @Input() @InputBoolean() nzAutoFocus: boolean = false;
@@ -52,28 +55,42 @@ export abstract class AbstractPickerComponent implements OnInit, OnChanges, Cont
     this.nzValue = this.isRange ? [] : null;
   }
 
+  protected destroyed$: Subject<void> = new Subject();
+  protected isCustomPlaceHolder: boolean = false;
+
   constructor(protected i18n: NzI18nService) {
   }
 
   ngOnInit(): void {
-    // Default locale (NOTE: Place here to assign default value due to the i18n'locale may change before ngOnInit)
+    // Subscribe the every locale change if the nzLocale is not handled by user
     if (!this.nzLocale) {
-      this.nzLocale = this.i18n.getLocaleData('DatePicker', {});
+      this.i18n.localeChange
+        .pipe(takeUntil(this.destroyed$))
+        .subscribe(() => this.setLocale());
     }
 
     // Default value
     this.initValue();
-
-    // Default placeholder
-    if (!this.nzPlaceHolder) {
-      this.nzPlaceHolder = this.isRange ? this.nzLocale.lang.rangePlaceholder : this.nzLocale.lang.placeholder;
-    }
   }
 
   ngOnChanges(changes: SimpleChanges): void {
     if (changes.nzPopupStyle) { // Always assign the popup style patch
       this.nzPopupStyle = this.nzPopupStyle ? { ...this.nzPopupStyle, ...POPUP_STYLE_PATCH } : POPUP_STYLE_PATCH;
     }
+
+    // Mark as customized placeholder by user once nzPlaceHolder assigned at the first time
+    if (changes.nzPlaceHolder && changes.nzPlaceHolder.firstChange && typeof this.nzPlaceHolder !== 'undefined') {
+      this.isCustomPlaceHolder = true;
+    }
+
+    if (changes.nzLocale) { // The nzLocale is currently handled by user
+      this.setDefaultPlaceHolder();
+    }
+  }
+
+  ngOnDestroy(): void {
+    this.destroyed$.next();
+    this.destroyed$.complete();
   }
 
   closeOverlay(): void {
@@ -138,6 +155,18 @@ export abstract class AbstractPickerComponent implements OnInit, OnChanges, Cont
   // | Internal methods
   // ------------------------------------------------------------------------
 
+  // Reload locale from i18n with side effects
+  private setLocale(): void {
+    this.nzLocale = this.i18n.getLocaleData('DatePicker', {});
+    this.setDefaultPlaceHolder();
+  }
+
+  private setDefaultPlaceHolder(): void {
+    if (!this.isCustomPlaceHolder && this.nzLocale) {
+      this.nzPlaceHolder = this.isRange ? this.nzLocale.lang.rangePlaceholder : this.nzLocale.lang.placeholder;
+    }
+  }
+
   private formatDate(date: CandyDate): string {
     return date ? this.i18n.formatDateCompatible(date.nativeDate, this.nzFormat) : '';
   }

components/date-picker/date-picker.component.spec.ts

@@ -10,6 +10,9 @@ import { NoopAnimationsModule } from '@angular/platform-browser/animations';
 import * as isSameDay from 'date-fns/is_same_day';
 
 import { dispatchKeyboardEvent, dispatchMouseEvent } from '../core/testing';
+import en_US from '../i18n/languages/en_US';
+import { NzI18nModule } from '../i18n/nz-i18n.module';
+import { NzI18nService } from '../i18n/nz-i18n.service';
 import { NzDatePickerModule } from './date-picker.module';
 import { PickerResultSingle } from './standard-types';
 
@@ -21,10 +24,11 @@ describe('NzDatePickerComponent', () => {
   let debugElement: DebugElement;
   let overlayContainer: OverlayContainer;
   let overlayContainerElement: HTMLElement;
+  let i18nService: NzI18nService;
 
   beforeEach(fakeAsync(() => {
     TestBed.configureTestingModule({
-      imports     : [ FormsModule, NoopAnimationsModule, NzDatePickerModule ],
+      imports     : [ FormsModule, NoopAnimationsModule, NzDatePickerModule, NzI18nModule ],
       providers   : [],
       declarations: [
         NzTestDatePickerComponent
@@ -40,9 +44,10 @@ describe('NzDatePickerComponent', () => {
     debugElement = fixture.debugElement;
   });
 
-  beforeEach(inject([ OverlayContainer ], (oc: OverlayContainer) => {
+  beforeEach(inject([ OverlayContainer, NzI18nService ], (oc: OverlayContainer, i18n: NzI18nService) => {
     overlayContainer = oc;
     overlayContainerElement = oc.getContainerElement();
+    i18nService = i18n;
   }));
 
   afterEach(() => {
@@ -67,6 +72,21 @@ describe('NzDatePickerComponent', () => {
       expect(getPickerContainer()).toBeNull();
     }));
 
+    it('should support changing language at runtime', fakeAsync(() => {
+      fixture.detectChanges();
+      expect(getPickerTrigger().placeholder).toBe('请选择日期');
+      i18nService.setLocale(en_US);
+      fixture.detectChanges();
+      expect(getPickerTrigger().placeholder).toBe('Select date');
+
+      dispatchMouseEvent(getPickerTrigger(), 'click');
+      fixture.detectChanges();
+      tick(500);
+      fixture.detectChanges();
+      expect((queryFromOverlay('.ant-calendar-date-input-wrap input.ant-calendar-input') as HTMLInputElement).placeholder).toBe('Select date');
+      expect(queryFromOverlay('.ant-calendar-table .ant-calendar-column-header-inner').textContent).toContain('Su');
+    }));
+
     /* Issue https://github.com/NG-ZORRO/ng-zorro-antd/issues/1539 */
     it('should be openable after closed by "Escape" key', fakeAsync(() => {
       fixture.detectChanges();

components/date-picker/demo/basic.ts

@@ -1,5 +1,6 @@
 import { Component } from '@angular/core';
 import * as getISOWeek from 'date-fns/get_iso_week';
+import { en_US, zh_CN, NzI18nService } from 'ng-zorro-antd';
 
 @Component({
   selector: 'nz-demo-date-picker-basic',
@@ -11,6 +12,8 @@ import * as getISOWeek from 'date-fns/get_iso_week';
     <nz-range-picker [(ngModel)]="dateRange" (ngModelChange)="onChange($event)" nzShowTime></nz-range-picker>
     <br>
     <nz-week-picker [(ngModel)]="date" (ngModelChange)="getWeek($event)" nzPlaceHolder="Select week"></nz-week-picker>
+    <br>
+    <button nz-button nzType="default" (click)="changeLanguage()">Switch language for all pickers</button>
   `,
   styles  : [ `
     nz-date-picker, nz-month-picker, nz-range-picker, nz-week-picker {
@@ -22,6 +25,9 @@ import * as getISOWeek from 'date-fns/get_iso_week';
 export class NzDemoDatePickerBasicComponent {
   date = null; // new Date();
   dateRange = []; // [ new Date(), addDays(new Date(), 3) ];
+  isEnglish = false;
+
+  constructor(private i18n: NzI18nService) {}
 
   onChange(result: Date): void {
     console.log('onChange: ', result);
@@ -30,4 +36,9 @@ export class NzDemoDatePickerBasicComponent {
   getWeek(result: Date): void {
     console.log('week: ', getISOWeek(result));
   }
+
+  changeLanguage(): void {
+    this.i18n.setLocale(this.isEnglish ? zh_CN : en_US);
+    this.isEnglish = !this.isEnglish;
+  }
 }