Angular 2 doesn't update my view after I add or edit item - user-interface

Question

I've finally made my app in angular 2. Everything is solved, except one thing. When I add item into my table or edited it, I can't see the change until I refresh page or click for example next page button (I have implemented pagination). I included:
<script src="node_modules/systemjs/dist/system-polyfills.js"></script>
<script src="node_modules/angular2/bundles/angular2-polyfills.js"></script>
in this order. My method for adding item is very simple:
addDepartment(item){
this._departmentService.addDepartment(item)
.subscribe(departments => this.department = departments.json());
this.getAll();}
Whhen I add item, and put breakpoint on get method, It is called correctly and I get right information from my DB, but I don't know why view isn't refreshed then. Do you have any idea why is it happened? Thanks for suggestions!
EDIT: department is just department: Department, where Department is interface with properties (departmentNo, departmentName, departmentLocation). The view for adding item looks like:
<form [ngFormModel]="myForm"
(ngSubmit)="addDepartment(newItem); showAddView=false" [hidden]="!showAddView" align="center">
<div>
<label for="editAbrv">Department name:</label><br>
<input type="text" [(ngModel)]="newItem.departmentName" [ngFormControl]="myForm.controls['departmentName']" >
<div *ngIf="myForm.controls['departmentName'].hasError('required')" class="ui error message"><b style="color:red;">Name is required</b></div>
</div>
<br/>
<div>
<label for="editAbrv">Department Location:</label><br>
<input type="text" [(ngModel)]="newItem.departmentLocation" [ngFormControl]="myForm.controls['departmentLocation']" >
<div *ngIf="myForm.controls['departmentLocation'].hasError('required')" class="ui error message"><b style="color:red;">Location is required</b></div>
</div>
<br/>
<div>
<button type="submit" [disabled]="!myForm.valid" class="ui button">Add item</button>
<button><a href="javascript:void(0);" (click)="showHide($event)" >
Cancel
</a></button>
</div>
</form>
and my department table is:
<table align="center">
<thead>
<tr>
<td>#</td>
<td><strong>Department</strong></td>
<td><strong>Department Location</strong></td>
<td><strong>Edit</strong></td>
<td><strong>Delete</strong></td>
</tr>
</thead>
<tbody>
<tr *ngFor="#department of departments | searchString:filter.value ; #i = index">
<td>{{i + 1}}.</td>
<td> {{department.departmentName}}</td>
<td>{{department.departmentLocation}}</td>
<td>
<button class="btnEdit" (click)="showEdit(department)">Edit</button>
</td>
<td>
<button class="btnDelete" (click)="deleteDepartment(department)" >Delete</button>
</td>
</tr>
</tbody>
</table>

Answer 1

With this code, you don't wait for the response of the addDepartment request and execute the getAll request directly.
addDepartment(item){
this._departmentService.addDepartment(item)
.subscribe(departments => this.department = departments.json());
this.getAll();
}
You should move the call to getAll within the callback registered in subscribe. At this moment, the addDepartment is actually done and you can reload the list...
The code could be refactored like this (it's a guess since I haven't the content of addDepartment and getAll methods):
addDepartment(item){
this._departmentService.addDepartment(item)
.subscribe(addedDepartment => {
this.department = this.getAll();
});
}

Answer 2

This issue occurs because of the way you're using departmant and how change detection works. When you use *ngFor="#department of departments", angular change detection looks for a object reference on departments array. When you update/change one of the items in this array object reference to the array itself doesn't change, so angular doesn't run change detection.
You have few options:
1) change reference of the array by replacing it with new array with updated values
2) tell angular explicitly to run change detection (which I think is easier in your case):
constructor(private _cdRef: ChangeDetectorRef) {...}
addDepartment(item){
this._departmentService.addDepartment(item)
.subscribe(departments => this.department = departments.json());
this.getAll();
this._cdRef.markForCheck();
}