nit

Author: sllethe

src/lib/list/selection-list.ts

@@ -9,29 +9,22 @@
 import {
   AfterContentInit,
   Component,
-  ContentChild,
   ContentChildren,
-  Directive,
   ElementRef,
   Input,
   Optional,
-  QueryList,
-  Renderer2,
   ViewEncapsulation,
   ChangeDetectionStrategy,
   OnDestroy,
-  EventEmitter,
-  Output,
-  ChangeDetectorRef
+  EventEmitter
 } from '@angular/core';
-import {coerceBooleanProperty, MdLine, MdLineSetter, SelectionModel} from '../core';
+import {coerceBooleanProperty, SelectionModel} from '../core';
 import {FocusKeyManager} from '../core/a11y/focus-key-manager';
 import {Subscription} from 'rxjs/Subscription';
 import {SPACE} from '../core/keyboard/keycodes';
 import {Focusable} from '../core/a11y/focus-key-manager';
 import {MdListOption} from './list-option';
 import {CanDisable, mixinDisabled} from '../core/common-behaviors/disabled';
-import {RxChain, switchMap, first, filter} from '../core/rxjs/index';
 import 'rxjs/add/observable/merge';
 import 'rxjs/add/observable/fromEvent';
 import 'rxjs/add/operator/filter';
@@ -71,11 +64,11 @@ export class MdSelectionList extends _MdSelectionListMixinBase
   /** Subscription to tabbing out from the selection-list. */
   private _tabOutSubscription: Subscription;
 
-  /** Subscription to option changes from the selection-list. */
-  private _optionsChangeSubscription: Subscription;
-
+  /** Subscription to all list options' onFocus events */
   private _optionsChangeSubscriptionOnFocus: Subscription;
-  private _optionsChangeSubscriptionDestory: Subscription;
+
+  /** Subscription to all list options' destroy events  */
+  private _optionsChangeSubscriptionDestroy: Subscription;
 
   /** The FocusKeyManager which handles focus. */
   _keyManager: FocusKeyManager;
@@ -106,25 +99,32 @@ export class MdSelectionList extends _MdSelectionListMixinBase
     }
 
     this._optionsChangeSubscriptionOnFocus = this.onFocusSubscription();
-    this._optionsChangeSubscriptionDestory = this.onDestorySubscription();
+    this._optionsChangeSubscriptionDestroy = this.onDestorySubscription();
   }
 
   ngOnDestroy(): void {
     if (this._tabOutSubscription) {
       this._tabOutSubscription.unsubscribe();
     }
 
-    if (this._optionsChangeSubscription) {
-      this._optionsChangeSubscription.unsubscribe();
+    if (this._optionsChangeSubscriptionDestroy) {
+      this._optionsChangeSubscriptionDestroy.unsubscribe();
+    }
+
+    if (this._optionsChangeSubscriptionOnFocus) {
+      this._optionsChangeSubscriptionOnFocus.unsubscribe();
     }
   }
 
   focus() {
     this._element.nativeElement.focus();
   }
 
+  /**
+   * Map all the options' destroy event subscriptions and merge them into one stream.
+   */
   onDestorySubscription(): Subscription {
-    return this.options.changes.startWith(this.options).switchMap((options) => {
+    let subscription = this.options.changes.startWith(this.options).switchMap((options) => {
       return Observable.merge(...options.map(option => option.destroy));
     }).subscribe(e => {
       let optionIndex: number = this.options.toArray().indexOf(e.option);
@@ -138,15 +138,20 @@ export class MdSelectionList extends _MdSelectionListMixinBase
       }
       e.option.destroy.unsubscribe();
     });
+    return subscription;
   }
 
+  /**
+   * Map all the options' onFocus event subscriptions and merge them into one stream.
+   */
   onFocusSubscription(): Subscription {
-    return this.options.changes.startWith(this.options).switchMap((options) => {
+    let subscription =  this.options.changes.startWith(this.options).switchMap((options) => {
       return Observable.merge(...options.map(option => option.onFocus));
     }).subscribe(e => {
       let optionIndex: number = this.options.toArray().indexOf(e.option);
       this._keyManager.updateActiveItemIndex(optionIndex);
     });
+    return subscription;
   }
 
   /** Passes relevant key presses to our key manager. */