Add beforeClose feature to dialog demo

Author: willshowell

src/demo-app/dialog/dialog-demo.html

@@ -75,7 +75,8 @@ <h2>Other options</h2>
   </md-card-content>
 </md-card>
 
-<p>Last close result: {{lastCloseResult}}</p>
+<p>Last afterClosed result: {{lastAfterClosedResult}}</p>
+<p>Last beforeClose result: {{lastBeforeCloseResult}}</p>
 
 <ng-template>
   I'm a template dialog. I've been opened {{numTemplateOpens}} times!

src/demo-app/dialog/dialog-demo.ts

@@ -11,7 +11,8 @@ import {MdDialog, MdDialogRef, MD_DIALOG_DATA} from '@angular/material';
 })
 export class DialogDemo {
   dialogRef: MdDialogRef<JazzDialog> | null;
-  lastCloseResult: string;
+  lastAfterClosedResult: string;
+  lastBeforeCloseResult: string;
   actionsAlignment: string;
   config = {
     disableClose: false,
@@ -51,8 +52,11 @@ export class DialogDemo {
   openJazz() {
     this.dialogRef = this.dialog.open(JazzDialog, this.config);
 
+    this.dialogRef.beforeClose().subscribe((result: string) => {
+      this.lastBeforeCloseResult = result;
+    });
     this.dialogRef.afterClosed().subscribe((result: string) => {
-      this.lastCloseResult = result;
+      this.lastAfterClosedResult = result;
       this.dialogRef = null;
     });
   }