feat: add change emitters to the Intl providers

Since we're switching all components to OnPush change detection, they won't necessarily react to dynamic changes in the i18n labels. These changes add an `EventEmitter` per provider that allow for components to react to those types of changes. Note that it's up to the consumer to call `provider.changes.emit()` in order to trigger the re-render.

Fixes angular#5738.

src/lib/datepicker/calendar.spec.ts

@@ -1,4 +1,4 @@
-import {async, ComponentFixture, TestBed} from '@angular/core/testing';
+import {async, ComponentFixture, inject, TestBed} from '@angular/core/testing';
 import {Component} from '@angular/core';
 import {MdCalendar} from './calendar';
 import {By} from '@angular/platform-browser';
@@ -148,6 +148,18 @@ describe('MdCalendar', () => {
       expect(testComponent.selected).toEqual(new Date(2017, JAN, 31));
     });
 
+    it('should re-render when the i18n labels have changed',
+      inject([MdDatepickerIntl], (intl: MdDatepickerIntl) => {
+        const button = fixture.debugElement.nativeElement
+            .querySelector('.mat-calendar-period-button');
+
+        intl.switchToYearViewLabel = 'Go to year view?';
+        intl.changes.emit();
+        fixture.detectChanges();
+
+        expect(button.getAttribute('aria-label')).toBe('Go to year view?');
+      }));
+
     describe('a11y', () => {
       describe('calendar body', () => {
         let calendarBodyEl: HTMLElement;

src/lib/datepicker/calendar.ts

@@ -17,7 +17,9 @@ import {
   NgZone,
   Optional,
   Output,
-  ViewEncapsulation
+  ViewEncapsulation,
+  ChangeDetectorRef,
+  OnDestroy,
 } from '@angular/core';
 import {
   DOWN_ARROW,
@@ -36,6 +38,7 @@ import {createMissingDateImplError} from './datepicker-errors';
 import {MD_DATE_FORMATS, MdDateFormats} from '../core/datetime/date-formats';
 import {MATERIAL_COMPATIBILITY_MODE} from '../core';
 import {first} from '../core/rxjs/index';
+import {Subscription} from 'rxjs/Subscription';
 
 
 /**
@@ -53,7 +56,9 @@ import {first} from '../core/rxjs/index';
   encapsulation: ViewEncapsulation.None,
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class MdCalendar<D> implements AfterContentInit {
+export class MdCalendar<D> implements AfterContentInit, OnDestroy {
+  private _intlChanges: Subscription;
+
   /** A date representing the period (month or year) to start the calendar in. */
   @Input() startAt: D;
 
@@ -123,13 +128,18 @@ export class MdCalendar<D> implements AfterContentInit {
               private _ngZone: NgZone,
               @Optional() @Inject(MATERIAL_COMPATIBILITY_MODE) public _isCompatibilityMode: boolean,
               @Optional() private _dateAdapter: DateAdapter<D>,
-              @Optional() @Inject(MD_DATE_FORMATS) private _dateFormats: MdDateFormats) {
+              @Optional() @Inject(MD_DATE_FORMATS) private _dateFormats: MdDateFormats,
+              changeDetectorRef: ChangeDetectorRef) {
+
     if (!this._dateAdapter) {
       throw createMissingDateImplError('DateAdapter');
     }
+
     if (!this._dateFormats) {
       throw createMissingDateImplError('MD_DATE_FORMATS');
     }
+
+    this._intlChanges = _intl.changes.subscribe(() => changeDetectorRef.markForCheck());
   }
 
   ngAfterContentInit() {
@@ -138,6 +148,10 @@ export class MdCalendar<D> implements AfterContentInit {
     this._monthView = this.startView != 'year';
   }
 
+  ngOnDestroy() {
+    this._intlChanges.unsubscribe();
+  }
+
   /** Handles date selection in the month view. */
   _dateSelected(date: D): void {
     if (!this._dateAdapter.sameDate(date, this.selected)) {

src/lib/datepicker/datepicker-intl.ts

@@ -6,12 +6,18 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Injectable} from '@angular/core';
+import {Injectable, EventEmitter} from '@angular/core';
 
 
 /** Datepicker data that requires internationalization. */
 @Injectable()
 export class MdDatepickerIntl {
+  /**
+   * Stream that emits whenever the labels here are changed. Use this to notify
+   * components if the labels have changed after initialization.
+   */
+  changes: EventEmitter<void> = new EventEmitter<void>();
+
   /** A label for the calendar popup (used by screen readers). */
   calendarLabel = 'Calendar';
 

src/lib/datepicker/datepicker-toggle.ts

@@ -6,10 +6,18 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {ChangeDetectionStrategy, Component, Input, ViewEncapsulation} from '@angular/core';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  Input,
+  ViewEncapsulation,
+  OnDestroy,
+  ChangeDetectorRef,
+} from '@angular/core';
 import {MdDatepicker} from './datepicker';
 import {MdDatepickerIntl} from './datepicker-intl';
 import {coerceBooleanProperty} from '@angular/cdk';
+import {Subscription} from 'rxjs/Subscription';
 
 
 @Component({
@@ -27,7 +35,9 @@ import {coerceBooleanProperty} from '@angular/cdk';
   encapsulation: ViewEncapsulation.None,
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class MdDatepickerToggle<D> {
+export class MdDatepickerToggle<D> implements OnDestroy {
+  private _intlChanges: Subscription;
+
   /** Datepicker instance that the button will toggle. */
   @Input('mdDatepickerToggle') datepicker: MdDatepicker<D>;
 
@@ -45,7 +55,13 @@ export class MdDatepickerToggle<D> {
   }
   private _disabled: boolean;
 
-  constructor(public _intl: MdDatepickerIntl) {}
+  constructor(public _intl: MdDatepickerIntl, changeDetectorRef: ChangeDetectorRef) {
+    this._intlChanges = _intl.changes.subscribe(() => changeDetectorRef.markForCheck());
+  }
+
+  ngOnDestroy() {
+    this._intlChanges.unsubscribe();
+  }
 
   _open(event: Event): void {
     if (this.datepicker && !this.disabled) {

src/lib/datepicker/datepicker.spec.ts

@@ -3,7 +3,7 @@ import {async, ComponentFixture, TestBed, inject} from '@angular/core/testing';
 import {NoopAnimationsModule} from '@angular/platform-browser/animations';
 import {FormControl, FormsModule, ReactiveFormsModule} from '@angular/forms';
 import {By} from '@angular/platform-browser';
-import {MdDatepickerModule} from './index';
+import {MdDatepickerModule, MdDatepickerIntl} from './index';
 import {MdDatepicker} from './datepicker';
 import {MdDatepickerInput} from './datepicker-input';
 import {MdInputModule} from '../input/index';
@@ -498,6 +498,17 @@ describe('MdDatepicker', () => {
 
         expect(document.activeElement).toBe(toggle, 'Expected focus to be restored to toggle.');
       });
+
+      it('should re-render when the i18n labels change',
+        inject([MdDatepickerIntl], (intl: MdDatepickerIntl) => {
+          const toggle = fixture.debugElement.query(By.css('button')).nativeElement;
+
+          intl.openCalendarLabel = 'Open the calendar, perhaps?';
+          intl.changes.emit();
+          fixture.detectChanges();
+
+          expect(toggle.getAttribute('aria-label')).toBe('Open the calendar, perhaps?');
+        }));
     });
 
     describe('datepicker inside input-container', () => {

src/lib/paginator/paginator-intl.ts

@@ -6,14 +6,20 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Injectable} from '@angular/core';
+import {Injectable, EventEmitter} from '@angular/core';
 
 /**
  * To modify the labels and text displayed, create a new instance of MdPaginatorIntl and
  * include it in a custom provider
  */
 @Injectable()
 export class MdPaginatorIntl {
+  /**
+   * Stream that emits whenever the labels here are changed. Use this to notify
+   * components if the labels have changed after initialization.
+   */
+  changes: EventEmitter<void> = new EventEmitter<void>();
+
   /** A label for the page size selector. */
   itemsPerPageLabel = 'Items per page:';
 

src/lib/paginator/paginator.spec.ts

@@ -1,4 +1,4 @@
-import {async, ComponentFixture, TestBed} from '@angular/core/testing';
+import {async, ComponentFixture, TestBed, inject} from '@angular/core/testing';
 import {MdPaginatorModule} from './index';
 import {MdPaginator, PageEvent} from './paginator';
 import {Component, ElementRef, ViewChild} from '@angular/core';
@@ -90,6 +90,17 @@ describe('MdPaginator', () => {
       const nextButton = fixture.nativeElement.querySelector('.mat-paginator-navigation-next');
       expect(nextButton.getAttribute('aria-label')).toBe('Next page');
     });
+
+    it('should re-render when the i18n labels change',
+      inject([MdPaginatorIntl], (intl: MdPaginatorIntl) => {
+        const label = fixture.nativeElement.querySelector('.mat-paginator-page-size-label');
+
+        intl.itemsPerPageLabel = '1337 items per page';
+        intl.changes.emit();
+        fixture.detectChanges();
+
+        expect(label.textContent).toBe('1337 items per page');
+      }));
   });
 
   describe('when navigating with the navigation buttons', () => {

src/lib/paginator/paginator.ts

@@ -13,10 +13,13 @@ import {
   Input,
   OnInit,
   Output,
-  ViewEncapsulation
+  ViewEncapsulation,
+  ChangeDetectorRef,
+  OnDestroy,
 } from '@angular/core';
 import {MdPaginatorIntl} from './paginator-intl';
 import {MATERIAL_COMPATIBILITY_MODE} from '../core';
+import {Subscription} from 'rxjs/Subscription';
 
 /**
  * Change event object that is emitted when the user selects a
@@ -52,8 +55,9 @@ export class PageEvent {
   changeDetection: ChangeDetectionStrategy.OnPush,
   encapsulation: ViewEncapsulation.None,
 })
-export class MdPaginator implements OnInit {
+export class MdPaginator implements OnInit, OnDestroy {
   private _initialized: boolean;
+  private _intlChanges: Subscription;
 
   /** The zero-based page index of the displayed list of items. Defaulted to 0. */
   @Input() pageIndex: number = 0;
@@ -85,13 +89,19 @@ export class MdPaginator implements OnInit {
   /** Displayed set of page size options. Will be sorted and include current page size. */
   _displayedPageSizeOptions: number[];
 
-  constructor(public _intl: MdPaginatorIntl) { }
+  constructor(public _intl: MdPaginatorIntl, changeDetectorRef: ChangeDetectorRef) {
+    this._intlChanges = _intl.changes.subscribe(() => changeDetectorRef.markForCheck());
+  }
 
   ngOnInit() {
     this._initialized = true;
     this._updateDisplayedPageSizeOptions();
   }
 
+  ngOnDestroy() {
+    this._intlChanges.unsubscribe();
+  }
+
   /** Advances to the next page if it exists. */
   nextPage() {
     if (!this.hasNextPage()) { return; }

src/lib/sort/sort-header-intl.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Injectable} from '@angular/core';
+import {Injectable, EventEmitter} from '@angular/core';
 import {SortDirection} from './sort-direction';
 
 /**
@@ -15,6 +15,13 @@ import {SortDirection} from './sort-direction';
  */
 @Injectable()
 export class MdSortHeaderIntl {
+  /**
+   * Stream that emits whenever the labels here are changed. Use this to notify
+   * components if the labels have changed after initialization.
+   */
+  changes: EventEmitter<void> = new EventEmitter<void>();
+
+  /** ARIA label for the sorting button. */
   sortButtonLabel = (id: string) => {
     return `Change sorting for ${id}`;
   }

src/lib/sort/sort-header.ts

@@ -16,6 +16,7 @@ import {CdkColumnDef} from '@angular/cdk';
 import {coerceBooleanProperty} from '../core';
 import {getMdSortHeaderNotContainedWithinMdSortError} from './sort-errors';
 import {Subscription} from 'rxjs/Subscription';
+import {merge} from 'rxjs/observable/merge';
 
 /**
  * Applies sorting behavior (click to change sort) and styles to an element, including an
@@ -39,8 +40,7 @@ import {Subscription} from 'rxjs/Subscription';
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class MdSortHeader implements MdSortable {
-  /** @docs-private  */
-  sortSubscription: Subscription;
+  private _rerenderSubscription: Subscription;
 
   /**
    * ID of this sort header. If used within the context of a CdkColumnDef, this will default to
@@ -65,14 +65,16 @@ export class MdSortHeader implements MdSortable {
   set _id(v: string) { this.id = v; }
 
   constructor(public _intl: MdSortHeaderIntl,
-              private _changeDetectorRef: ChangeDetectorRef,
+              changeDetectorRef: ChangeDetectorRef,
               @Optional() public _sort: MdSort,
               @Optional() public _cdkColumnDef: CdkColumnDef) {
     if (!_sort) {
       throw getMdSortHeaderNotContainedWithinMdSortError();
     }
 
-    this.sortSubscription = _sort.mdSortChange.subscribe(() => _changeDetectorRef.markForCheck());
+    this._rerenderSubscription = merge(_sort.mdSortChange, _intl.changes).subscribe(() => {
+      changeDetectorRef.markForCheck();
+    });
   }
 
   ngOnInit() {
@@ -85,7 +87,7 @@ export class MdSortHeader implements MdSortable {
 
   ngOnDestroy() {
     this._sort.deregister(this);
-    this.sortSubscription.unsubscribe();
+    this._rerenderSubscription.unsubscribe();
   }
 
   /** Whether this MdSortHeader is currently sorted in either ascending or descending order. */

src/lib/sort/sort.spec.ts

@@ -1,6 +1,7 @@
-import {async, ComponentFixture, TestBed} from '@angular/core/testing';
+import {async, ComponentFixture, TestBed, inject} from '@angular/core/testing';
 import {Component, ElementRef, ViewChild} from '@angular/core';
-import {MdSort, MdSortHeader, Sort, SortDirection, MdSortModule} from './index';
+import {By} from '@angular/platform-browser';
+import {MdSort, MdSortHeader, Sort, SortDirection, MdSortModule, MdSortHeaderIntl} from './index';
 import {CdkTableModule, DataSource, CollectionViewer} from '@angular/cdk';
 import {Observable} from 'rxjs/Observable';
 import {dispatchMouseEvent} from '@angular/cdk/testing';
@@ -126,6 +127,18 @@ describe('MdSort', () => {
     const button = fixture.nativeElement.querySelector('#defaultSortHeaderA button');
     expect(button.getAttribute('aria-label')).toBe('Change sorting for defaultSortHeaderA');
   });
+
+  it('should re-render when the i18n labels have changed',
+    inject([MdSortHeaderIntl], (intl: MdSortHeaderIntl) => {
+      const header = fixture.debugElement.query(By.directive(MdSortHeader)).nativeElement;
+      const button = header.querySelector('.mat-sort-header-button');
+
+      intl.sortButtonLabel = () => 'Sort all of the things';
+      intl.changes.emit();
+      fixture.detectChanges();
+
+      expect(button.getAttribute('aria-label')).toBe('Sort all of the things');
+    }));
 });
 
 /**