Added progress bar to file downloads

Added two new API calls, to update the server to a particular version and to get the updater status

You can now update through the UI, and a status dialog displays after

src/app/updater/updater.component.html

@@ -0,0 +1,18 @@
+<div style="display: block">
+    <div style="display: inline-block">
+        <ng-container i18n="Select a version">Select a version:</ng-container>
+    </div>
+    <div *ngIf="availableVersions" style="display: inline-block; margin-left: 15px;">
+        <mat-form-field>
+        <mat-select [(ngModel)]="selectedVersion">
+            <mat-option *ngFor="let version of availableVersionsFiltered" [value]="version['tag_name']">
+                {{version['tag_name'] + (version === latestStableRelease ? ' - Latest Stable' : '') + (version['tag_name'] === CURRENT_VERSION ? ' - Current Version' : '')}}
+            </mat-option>
+        </mat-select>
+        </mat-form-field>
+    </div>
+    <div *ngIf="selectedVersion && selectedVersion !== CURRENT_VERSION" style="display: inline-block; margin-left: 15px;">
+        <button (click)="updateServer()" color="accent" mat-raised-button><mat-icon>update</mat-icon>&nbsp;&nbsp;
+            <ng-container *ngIf="selectedVersion > CURRENT_VERSION">Upgrade to</ng-container><ng-container *ngIf="selectedVersion < CURRENT_VERSION">Downgrade to</ng-container>&nbsp;{{selectedVersion}}</button>
+    </div>
+</div>

src/app/updater/updater.component.spec.ts

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+import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+
+import { UpdaterComponent } from './updater.component';
+
+describe('UpdaterComponent', () => {
+  let component: UpdaterComponent;
+  let fixture: ComponentFixture<UpdaterComponent>;
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      declarations: [ UpdaterComponent ]
+    })
+    .compileComponents();
+  }));
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(UpdaterComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+});

src/app/updater/updater.component.ts

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+import { Component, OnInit } from '@angular/core';
+import { PostsService } from 'app/posts.services';
+import { CURRENT_VERSION } from 'app/consts';
+import { MatDialog } from '@angular/material/dialog';
+import { UpdateProgressDialogComponent } from 'app/dialogs/update-progress-dialog/update-progress-dialog.component';
+@Component({
+  selector: 'app-updater',
+  templateUrl: './updater.component.html',
+  styleUrls: ['./updater.component.scss']
+})
+export class UpdaterComponent implements OnInit {
+
+  availableVersions = null;
+  availableVersionsFiltered = [];
+  versionsShowLimit = 5;
+  latestStableRelease = null;
+  selectedVersion = null;
+  CURRENT_VERSION = CURRENT_VERSION;
+
+  constructor(private postsService: PostsService, private dialog: MatDialog) { }
+
+  ngOnInit(): void {
+    this.getAvailableVersions();
+  }
+
+  updateServer() {
+    this.postsService.updateServer(this.selectedVersion).subscribe(res => {
+      if (res['success']) {
+        this.openUpdateProgressDialog();
+      }
+    });
+  }
+
+  getAvailableVersions() {
+    this.availableVersionsFiltered = [];
+    this.postsService.getAvailableRelease().subscribe(res => {
+      this.availableVersions = res;
+      for (let i = 0; i < this.availableVersions.length; i++) {
+        const currentVersion = this.availableVersions[i];
+        // if a stable release has not been found and the version is not "rc" (meaning it's stable) then set it as the stable release
+        if (!this.latestStableRelease && !currentVersion.tag_name.includes('rc')) {
+          this.latestStableRelease = currentVersion;
+          this.selectedVersion = this.latestStableRelease.tag_name;
+        }
+
+        if (this.latestStableRelease && i >= this.versionsShowLimit) {
+          break;
+        }
+
+        this.availableVersionsFiltered.push(currentVersion);
+      }
+    });
+  }
+
+  openUpdateProgressDialog() {
+    this.dialog.open(UpdateProgressDialogComponent, {
+      minWidth: '300px',
+      minHeight: '200px'
+    });
+  }
+
+}