Set selected state of list option item in selection list OnInit. (#7189)

src/lib/list/selection-list.spec.ts

@@ -219,6 +219,34 @@ describe('MatSelectionList', () => {
     });
   });
 
+  describe('with list option selected', () => {
+    let fixture: ComponentFixture<SelectionListWithListOptions>;
+    let listItemEl: DebugElement;
+    let selectionList: DebugElement;
+
+    beforeEach(async(() => {
+      TestBed.configureTestingModule({
+        imports: [MdListModule],
+        declarations: [SelectionListWithSelecedOption],
+      });
+
+      TestBed.compileComponents();
+    }));
+
+    beforeEach(async(() => {
+      fixture = TestBed.createComponent(SelectionListWithSelecedOption);
+      listItemEl = fixture.debugElement.query(By.directive(MdListOption));
+      selectionList = fixture.debugElement.query(By.directive(MdSelectionList));
+      fixture.detectChanges();
+    }));
+
+    it('should set its initial selected state in the selectedOptions', () => {
+      let optionEl = listItemEl.injector.get(MdListOption);
+      let selectedOptions = selectionList.componentInstance.selectedOptions;
+      expect(selectedOptions.isSelected(optionEl)).toBeTruthy();
+    });
+  });
+
   describe('with single option', () => {
     let fixture: ComponentFixture<SelectionListWithOnlyOneOption>;
     let listOption: DebugElement;
@@ -456,6 +484,13 @@ class SelectionListWithDisabledOption {
   disableItem: boolean = false;
 }
 
+@Component({template: `
+  <mat-selection-list>
+    <md-list-option [selected]="true">Item</md-list-option>
+  </mat-selection-list>`})
+class SelectionListWithSelecedOption {
+}
+
 @Component({template: `
   <mat-selection-list id = "selection-list-4">
     <mat-list-option checkboxPosition = "after" class="test-focus" id="123">

src/lib/list/selection-list.ts

@@ -23,6 +23,7 @@ import {
   Inject,
   Input,
   OnDestroy,
+  OnInit,
   Optional,
   Output,
   QueryList,
@@ -82,8 +83,7 @@ const FOCUSED_STYLE: string = 'mat-list-item-focus';
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class MatListOption extends _MatListOptionMixinBase
-    implements AfterContentInit, OnDestroy, FocusableOption, CanDisableRipple {
-
+    implements AfterContentInit, OnInit, OnDestroy, FocusableOption, CanDisableRipple {
   private _lineSetter: MatLineSetter;
   private _selected: boolean = false;
   private _disabled: boolean = false;
@@ -129,6 +129,12 @@ export class MatListOption extends _MatListOptionMixinBase
     super();
   }
 
+  ngOnInit() {
+    if (this.selected) {
+      this.selectionList.selectedOptions.select(this);
+    }
+  }
+
   ngAfterContentInit() {
     this._lineSetter = new MatLineSetter(this._lines, this._renderer, this._element);