diff --git a/src/app/services/backend.service.ts b/src/app/services/backend.service.ts
index 9761298..ef79bad 100644
--- a/src/app/services/backend.service.ts
+++ b/src/app/services/backend.service.ts
@@ -1,282 +1,435 @@
-import { Injectable } from '@angular/core';
-import { HttpClient, HttpResponse } from '@angular/common/http';
-import { Observable } from 'rxjs';
-import { environment } from '../../environments/environment';
-
-@Injectable()
-export class BackendService {
-  constructor(private httpClient: HttpClient) {}
-
-  // Tasks
-  public getTasks(): Observable<HttpResponse<ScrumTask[]>> {
-    const url = `${environment.apiUrl}/tasks`;
-    return this.httpClient.get<ScrumTask[]>(url, { observe: 'response' });
-  }
-
-  public getTask(id: number): Observable<HttpResponse<ScrumTask>> {
-    const url = `${environment.apiUrl}/tasks/${id}`;
-    return this.httpClient.get<ScrumTask>(url, { observe: 'response' });
-  }
-
-  public postTask(task: ScrumTask): Observable<HttpResponse<ScrumTask>> {
-    const url = `${environment.apiUrl}/tasks`;
-    return this.httpClient.post<ScrumTask>(url, task, { observe: 'response' });
-  }
-
-  public putTask(task: ScrumTask): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/tasks/${task.id}`;
-    return this.httpClient.put(url, task, { observe: 'response' });
-  }
-
-  public deleteTask(task: ScrumTask): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/tasks/${task.id}`;
-    return this.httpClient.delete(url, { observe: 'response' });
-  }
-
-  // Userstories
-  public getUserstories(): Observable<HttpResponse<ScrumUserstory[]>> {
-    const url = `${environment.apiUrl}/userstories`;
-    return this.httpClient.get<ScrumUserstory[]>(url, { observe: 'response' });
-  }
-
-  public getUserstory(id: number): Observable<HttpResponse<ScrumUserstory>> {
-    const url = `${environment.apiUrl}/userstories/${id}`;
-    return this.httpClient.get<ScrumUserstory>(url, { observe: 'response' });
-  }
-
-  public postUserstory(
-    userstory: ScrumUserstory
-  ): Observable<HttpResponse<ScrumUserstory>> {
-    const url = `${environment.apiUrl}/userstories`;
-    return this.httpClient.post<ScrumUserstory>(url, userstory, {
-      observe: 'response',
-    });
-  }
-
-  public putUserstory(
-    userstory: ScrumUserstory
-  ): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/userstories/${userstory.id}`;
-    return this.httpClient.put(url, userstory, { observe: 'response' });
-  }
-
-  public deleteUserstory(
-    userstory: ScrumUserstory
-  ): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/userstories/${userstory.id}`;
-    return this.httpClient.delete(url, { observe: 'response' });
-  }
-
-  // Sprints
-  public getSprints(): Observable<HttpResponse<ScrumSprint[]>> {
-    const url = `${environment.apiUrl}/sprints`;
-    return this.httpClient.get<ScrumSprint[]>(url, { observe: 'response' });
-  }
-
-  public getSprint(id: number): Observable<HttpResponse<ScrumSprint>> {
-    const url = `${environment.apiUrl}/sprints/${id}`;
-    return this.httpClient.get<ScrumSprint>(url, { observe: 'response' });
-  }
-
-  public postSprint(
-    sprint: ScrumSprint
-  ): Observable<HttpResponse<ScrumSprint>> {
-    const url = `${environment.apiUrl}/sprints`;
-    return this.httpClient.post<ScrumSprint>(url, sprint, {
-      observe: 'response',
-    });
-  }
-
-  public putSprint(sprint: ScrumSprint): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/sprints/${sprint.id}`;
-    return this.httpClient.put(url, sprint, { observe: 'response' });
-  }
-
-  public deleteSprint(sprint: ScrumSprint): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/sprints/${sprint.id}`;
-    return this.httpClient.delete(url, { observe: 'response' });
-  }
-
-  // Categories
-  public getCategories(): Observable<HttpResponse<ScrumCategory[]>> {
-    const url = `${environment.apiUrl}/categories`;
-    return this.httpClient.get<ScrumCategory[]>(url, { observe: 'response' });
-  }
-
-  public getCategory(id: number): Observable<HttpResponse<ScrumCategory>> {
-    const url = `${environment.apiUrl}/categories/${id}`;
-    return this.httpClient.get<ScrumCategory>(url, { observe: 'response' });
-  }
-
-  public postCategory(
-    category: ScrumCategory
-  ): Observable<HttpResponse<ScrumCategory>> {
-    const url = `${environment.apiUrl}/categories`;
-    return this.httpClient.post<ScrumCategory>(url, category, {
-      observe: 'response',
-    });
-  }
-
-  public putCategory(category: ScrumCategory): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/categories/${category.id}`;
-    return this.httpClient.put(url, category, { observe: 'response' });
-  }
-
-  public deleteCategory(
-    category: ScrumCategory
-  ): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/categories/${category.id}`;
-    return this.httpClient.delete(url, { observe: 'response' });
-  }
-
-  // Status
-  public getAllStatus(): Observable<HttpResponse<ScrumStatus[]>> {
-    const url = `${environment.apiUrl}/status`;
-    return this.httpClient.get<ScrumStatus[]>(url, { observe: 'response' });
-  }
-
-  public getStatus(id: number): Observable<HttpResponse<ScrumStatus>> {
-    const url = `${environment.apiUrl}/status/${id}`;
-    return this.httpClient.get<ScrumStatus>(url, { observe: 'response' });
-  }
-
-  public postStatus(
-    status: ScrumStatus
-  ): Observable<HttpResponse<ScrumStatus>> {
-    const url = `${environment.apiUrl}/status`;
-    return this.httpClient.post<ScrumStatus>(url, status, {
-      observe: 'response',
-    });
-  }
-
-  public putStatus(status: ScrumStatus): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/status/${status.id}`;
-    return this.httpClient.put(url, status, { observe: 'response' });
-  }
-
-  public deleteStatus(status: ScrumStatus): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/status/${status.id}`;
-    return this.httpClient.delete(url, { observe: 'response' });
-  }
-
-  // Users
-  public getUsers(): Observable<HttpResponse<ScrumUser[]>> {
-    const url = `${environment.apiUrl}/users`;
-    return this.httpClient.get<ScrumUser[]>(url, { observe: 'response' });
-  }
-
-  public getUser(id: number): Observable<HttpResponse<ScrumUser>> {
-    const url = `${environment.apiUrl}/users/${id}`;
-    return this.httpClient.get<ScrumUser>(url, { observe: 'response' });
-  }
-
-  public postUser(user: ScrumUser): Observable<HttpResponse<ScrumUser>> {
-    const url = `${environment.apiUrl}/users`;
-    return this.httpClient.post<ScrumUser>(url, user, { observe: 'response' });
-  }
-
-  public putUser(user: ScrumUser): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/users/${user.id}`;
-    return this.httpClient.put(url, user, { observe: 'response' });
-  }
-
-  public deleteUser(user: ScrumUser): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/users/${user.id}`;
-    return this.httpClient.delete(url, { observe: 'response' });
-  }
-
-  // Projects
-  public getProjects(): Observable<HttpResponse<ScrumProject[]>> {
-    const url = `${environment.apiUrl}/projects`;
-    return this.httpClient.get<ScrumProject[]>(url, { observe: 'response' });
-  }
-
-  public getProject(id: number): Observable<HttpResponse<ScrumProject>> {
-    const url = `${environment.apiUrl}/projects/${id}`;
-    return this.httpClient.get<ScrumProject>(url, { observe: 'response' });
-  }
-
-  public postProject(
-    project: ScrumProject
-  ): Observable<HttpResponse<ScrumProject>> {
-    const url = `${environment.apiUrl}/projects`;
-    return this.httpClient.post<ScrumProject>(url, project, {
-      observe: 'response',
-    });
-  }
-
-  public putProject(project: ScrumProject): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/projects/${project.id}`;
-    return this.httpClient.put(url, project, { observe: 'response' });
-  }
-
-  public deleteProject(project: ScrumProject): Observable<HttpResponse<any>> {
-    const url = `${environment.apiUrl}/projects/${project.id}`;
-    return this.httpClient.delete(url, { observe: 'response' });
-  }
-}
-
-export enum Priority {
-  High = 'high',
-  Medium = 'medium',
-  Low = 'low',
-}
-
-export interface ScrumTask {
-  id?: number;
-  title: string;
-  content?: string;
-  statusid?: number;
-  categoryid?: number;
-  assignedtoid?: number;
-  sprintid?: number;
-  projectid?: number;
-  userstoryid?: number;
-  priority?: Priority;
-}
-
-export interface ScrumUserstory {
-  id?: number;
-  title: string;
-  content?: string;
-  priority?: Priority;
-  statusid?: number;
-  categoryid?: number;
-  sprintid?: number;
-  createdbyid?: number;
-  projectid?: number;
-}
-
-export interface ScrumSprint {
-  id?: number;
-  title: string;
-  description?: string;
-  startDate: string;
-  endDate: string;
-  projectid?: number;
-}
-
-export interface ScrumCategory {
-  id?: number;
-  title: string;
-  description?: string;
-  color?: string;
-  project?: number;
-}
-
-export interface ScrumStatus {
-  id?: number;
-  title: string;
-  description: string;
-}
-
-export interface ScrumUser {
-  id?: number;
-  name: string;
-}
-
-export interface ScrumProject {
-  id?: number;
-  title: string;
-  isprivate: boolean;
-}
+import { Injectable } from '@angular/core';
+import { HttpClient, HttpResponse } from '@angular/common/http';
+import { Observable } from 'rxjs';
+import { environment } from '../../environments/environment';
+
+/**
+ * Provides access to the backend via HTTP.
+ */
+@Injectable()
+export class BackendService {
+  constructor(private httpClient: HttpClient) {}
+
+  // Tasks
+
+  /**
+   * Return all tasks.
+   */
+  public getTasks(): Observable<HttpResponse<ScrumTask[]>> {
+    const url = `${environment.apiUrl}/tasks`;
+    return this.httpClient.get<ScrumTask[]>(url, { observe: 'response' });
+  }
+
+  /**
+   * Return the task with a specific id.
+   */
+  public getTask(id: number): Observable<HttpResponse<ScrumTask>> {
+    const url = `${environment.apiUrl}/tasks/${id}`;
+    return this.httpClient.get<ScrumTask>(url, { observe: 'response' });
+  }
+
+  /**
+   * Create a new task, if successful, the newly created task will be returned.
+   */
+  public postTask(task: ScrumTask): Observable<HttpResponse<ScrumTask>> {
+    const url = `${environment.apiUrl}/tasks`;
+    return this.httpClient.post<ScrumTask>(url, task, { observe: 'response' });
+  }
+
+  /**
+   * Replace an existing task with a new one.
+   */
+  public putTask(task: ScrumTask): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/tasks/${task.id}`;
+    return this.httpClient.put(url, task, { observe: 'response' });
+  }
+
+  /**
+   * Delete a task.
+   */
+  public deleteTask(task: ScrumTask): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/tasks/${task.id}`;
+    return this.httpClient.delete(url, { observe: 'response' });
+  }
+
+  // Userstories
+
+  /**
+   * Return all userstories.
+   */
+  public getUserstories(): Observable<HttpResponse<ScrumUserstory[]>> {
+    const url = `${environment.apiUrl}/userstories`;
+    return this.httpClient.get<ScrumUserstory[]>(url, { observe: 'response' });
+  }
+
+  /**
+   * Return the userstory with a specific id.
+   */
+  public getUserstory(id: number): Observable<HttpResponse<ScrumUserstory>> {
+    const url = `${environment.apiUrl}/userstories/${id}`;
+    return this.httpClient.get<ScrumUserstory>(url, { observe: 'response' });
+  }
+
+  /**
+   * Create a new userstory, if successful, the newly created userstory will be returned.
+   */
+  public postUserstory(
+    userstory: ScrumUserstory
+  ): Observable<HttpResponse<ScrumUserstory>> {
+    const url = `${environment.apiUrl}/userstories`;
+    return this.httpClient.post<ScrumUserstory>(url, userstory, {
+      observe: 'response',
+    });
+  }
+
+  /**
+   * Replace an existing userstory with a new one.
+   */
+  public putUserstory(
+    userstory: ScrumUserstory
+  ): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/userstories/${userstory.id}`;
+    return this.httpClient.put(url, userstory, { observe: 'response' });
+  }
+
+  /**
+   * Delete a userstory.
+   */
+  public deleteUserstory(
+    userstory: ScrumUserstory
+  ): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/userstories/${userstory.id}`;
+    return this.httpClient.delete(url, { observe: 'response' });
+  }
+
+  // Sprints
+
+  /**
+   * Return all sprints.
+   */
+  public getSprints(): Observable<HttpResponse<ScrumSprint[]>> {
+    const url = `${environment.apiUrl}/sprints`;
+    return this.httpClient.get<ScrumSprint[]>(url, { observe: 'response' });
+  }
+
+  /**
+   * Return the sprint with a specific id.
+   */
+  public getSprint(id: number): Observable<HttpResponse<ScrumSprint>> {
+    const url = `${environment.apiUrl}/sprints/${id}`;
+    return this.httpClient.get<ScrumSprint>(url, { observe: 'response' });
+  }
+
+  /**
+   * Create a new sprint, if successful, the newly created sprint will be returned.
+   */
+  public postSprint(
+    sprint: ScrumSprint
+  ): Observable<HttpResponse<ScrumSprint>> {
+    const url = `${environment.apiUrl}/sprints`;
+    return this.httpClient.post<ScrumSprint>(url, sprint, {
+      observe: 'response',
+    });
+  }
+
+  /**
+   * Replace an existing sprint with a new one.
+   */
+  public putSprint(sprint: ScrumSprint): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/sprints/${sprint.id}`;
+    return this.httpClient.put(url, sprint, { observe: 'response' });
+  }
+
+  /**
+   * Delete a sprint.
+   */
+  public deleteSprint(sprint: ScrumSprint): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/sprints/${sprint.id}`;
+    return this.httpClient.delete(url, { observe: 'response' });
+  }
+
+  // Categories
+
+  /**
+   * Return all categories.
+   */
+  public getCategories(): Observable<HttpResponse<ScrumCategory[]>> {
+    const url = `${environment.apiUrl}/categories`;
+    return this.httpClient.get<ScrumCategory[]>(url, { observe: 'response' });
+  }
+
+  /**
+   * Return the category with a specific id.
+   */
+  public getCategory(id: number): Observable<HttpResponse<ScrumCategory>> {
+    const url = `${environment.apiUrl}/categories/${id}`;
+    return this.httpClient.get<ScrumCategory>(url, { observe: 'response' });
+  }
+
+  /**
+   * Create a new category, if successful, the newly created category will be returned.
+   */
+  public postCategory(
+    category: ScrumCategory
+  ): Observable<HttpResponse<ScrumCategory>> {
+    const url = `${environment.apiUrl}/categories`;
+    return this.httpClient.post<ScrumCategory>(url, category, {
+      observe: 'response',
+    });
+  }
+
+  /**
+   * Replace an existing category with a new one.
+   */
+  public putCategory(category: ScrumCategory): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/categories/${category.id}`;
+    return this.httpClient.put(url, category, { observe: 'response' });
+  }
+
+  /**
+   * Delete a category.
+   */
+  public deleteCategory(
+    category: ScrumCategory
+  ): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/categories/${category.id}`;
+    return this.httpClient.delete(url, { observe: 'response' });
+  }
+
+  // Status
+
+  /**
+   * Return all status.
+   */
+  public getAllStatus(): Observable<HttpResponse<ScrumStatus[]>> {
+    const url = `${environment.apiUrl}/status`;
+    return this.httpClient.get<ScrumStatus[]>(url, { observe: 'response' });
+  }
+
+  /**
+   * Return the status with a specific id.
+   */
+  public getStatus(id: number): Observable<HttpResponse<ScrumStatus>> {
+    const url = `${environment.apiUrl}/status/${id}`;
+    return this.httpClient.get<ScrumStatus>(url, { observe: 'response' });
+  }
+
+  /**
+   * Create a new status, if successful, the newly created status will be returned.
+   */
+  public postStatus(
+    status: ScrumStatus
+  ): Observable<HttpResponse<ScrumStatus>> {
+    const url = `${environment.apiUrl}/status`;
+    return this.httpClient.post<ScrumStatus>(url, status, {
+      observe: 'response',
+    });
+  }
+
+  /**
+   * Replace an existing status with a new one.
+   */
+  public putStatus(status: ScrumStatus): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/status/${status.id}`;
+    return this.httpClient.put(url, status, { observe: 'response' });
+  }
+
+  /**
+   * Delete a status.
+   */
+  public deleteStatus(status: ScrumStatus): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/status/${status.id}`;
+    return this.httpClient.delete(url, { observe: 'response' });
+  }
+
+  // Users
+
+  /**
+   * Return all users.
+   */
+  public getUsers(): Observable<HttpResponse<ScrumUser[]>> {
+    const url = `${environment.apiUrl}/users`;
+    return this.httpClient.get<ScrumUser[]>(url, { observe: 'response' });
+  }
+
+  /**
+   * Return the user with a specific id.
+   */
+  public getUser(id: number): Observable<HttpResponse<ScrumUser>> {
+    const url = `${environment.apiUrl}/users/${id}`;
+    return this.httpClient.get<ScrumUser>(url, { observe: 'response' });
+  }
+
+  /**
+   * Create a new user, if successful, the newly created user will be returned.
+   */
+  public postUser(user: ScrumUser): Observable<HttpResponse<ScrumUser>> {
+    const url = `${environment.apiUrl}/users`;
+    return this.httpClient.post<ScrumUser>(url, user, { observe: 'response' });
+  }
+
+  /**
+   * Replace an existing user with a new one.
+   */
+  public putUser(user: ScrumUser): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/users/${user.id}`;
+    return this.httpClient.put(url, user, { observe: 'response' });
+  }
+
+  /**
+   * Delete a user.
+   */
+  public deleteUser(user: ScrumUser): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/users/${user.id}`;
+    return this.httpClient.delete(url, { observe: 'response' });
+  }
+
+  // Projects
+
+  /**
+   * Return all projects.
+   */
+  public getProjects(): Observable<HttpResponse<ScrumProject[]>> {
+    const url = `${environment.apiUrl}/projects`;
+    return this.httpClient.get<ScrumProject[]>(url, { observe: 'response' });
+  }
+
+  /**
+   * Return the project with a specific id.
+   */
+  public getProject(id: number): Observable<HttpResponse<ScrumProject>> {
+    const url = `${environment.apiUrl}/projects/${id}`;
+    return this.httpClient.get<ScrumProject>(url, { observe: 'response' });
+  }
+
+  /**
+   * Create a new project, if successful, the newly created project will be returned.
+   */
+  public postProject(
+    project: ScrumProject
+  ): Observable<HttpResponse<ScrumProject>> {
+    const url = `${environment.apiUrl}/projects`;
+    return this.httpClient.post<ScrumProject>(url, project, {
+      observe: 'response',
+    });
+  }
+
+  /**
+   * Replace an existing project with a new one.
+   */
+  public putProject(project: ScrumProject): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/projects/${project.id}`;
+    return this.httpClient.put(url, project, { observe: 'response' });
+  }
+
+  /**
+   * Delete a project.
+   */
+  public deleteProject(project: ScrumProject): Observable<HttpResponse<any>> {
+    const url = `${environment.apiUrl}/projects/${project.id}`;
+    return this.httpClient.delete(url, { observe: 'response' });
+  }
+}
+
+/**
+ * @summary Represents the priority of a task or userstory.
+ */
+export enum Priority {
+  High = 'high',
+  Medium = 'medium',
+  Low = 'low',
+}
+
+/**
+ * @summary Represents a task in an agile work process.
+ * @description A task is a small piece of work, associated with a larger userstory.
+ */
+export interface ScrumTask {
+  id?: number;
+  title: string;
+  content?: string;
+  statusid?: number;
+  categoryid?: number;
+  assignedtoid?: number;
+  sprintid?: number;
+  projectid?: number;
+  userstoryid?: number;
+  priority?: Priority;
+}
+
+/**
+ * @summary Represents a userstory in an agile work process.
+ * @description A userstory is a piece of work that can be done in one sprint.
+ * It can be further divided into multiple tasks.
+ */
+export interface ScrumUserstory {
+  id?: number;
+  title: string;
+  content?: string;
+  priority?: Priority;
+  statusid?: number;
+  categoryid?: number;
+  sprintid?: number;
+  createdbyid?: number;
+  projectid?: number;
+}
+
+/**
+ * @summary Represents an agile sprint.
+ * @description A sprint is typically one to four weeks long.
+ * Userstories are started and completed during one sprint.
+ * </remarks>
+ */
+export interface ScrumSprint{
+    id?: number;
+    title: string;
+    description?: string;
+    startDate: string;
+    endDate: string;
+    projectid?: number;
+}
+
+/**
+ * @summary Represents a category of userstories.
+ * @description Every userstory can optionally be associated with a single category.
+ * This can be helpful to organize work in larger teams.
+ */
+export interface ScrumCategory {
+  id?: number;
+  title: string;
+  description?: string;
+  color?: string;
+  project?: number;
+}
+
+/**
+ * @summary Represents the status of a task or userstory.
+ * @description Classic status are "Backlog", "In Progress" and "Done", but
+ * teams can create others to fit their individual workflow.
+ */
+export interface ScrumStatus {
+  id?: number;
+  title: string;
+  description: string;
+}
+
+/**
+ * @summary Represents a team member that can work on userstories.
+ * @description This allows teams to track who is working on a userstory
+ * at a given time.
+ */
+export interface ScrumUser {
+  id?: number;
+  name: string;
+}
+
+/**
+ * @summary Represents a project that the team works on.
+ * @description Userstories and sprints can be categorized into projects,
+ * to help organization for larger teams.
+ */
+export interface ScrumProject {
+  id?: number;
+  title: string;
+  isprivate: boolean;
+}
diff --git a/src/app/services/sorting.service.ts b/src/app/services/sorting.service.ts
index 7907ad9..a3e471f 100644
--- a/src/app/services/sorting.service.ts
+++ b/src/app/services/sorting.service.ts
@@ -1,24 +1,45 @@
-import { Priority } from './backend.service';
-
-export function sortByNumberAscending<T>(items: T[], key: (T) => number) {
-  return items.sort((a, b) => key(a) - key(b));
-}
-
-export function sortByStringAscending<T>(items: T[], key: (T) => string) {
-  return items.sort((a, b) => key(a).localeCompare(key(b)));
-}
-
-export function sortByDateAscending<T>(items: T[], key: (T) => Date) {
-  return items.sort((a, b) =>  (key(a) as any) - (key(b) as any));
-}
-
-export function getNumberForPriority(priority: Priority): number {
-  switch (priority) {
-    case Priority.High:
-      return 2;
-    case Priority.Medium:
-      return 1;
-    case Priority.Low:
-      return 0;
-  }
-}
+import {Priority} from './backend.service';
+
+/**
+ * Sort an array in place by a number associated with that item.
+ * @param items The items to sort.
+ * @param key Returns the number associated with an item.
+ */
+export function sortByNumberAscending<T>(items: T[], key: (T) => number) {
+  return items.sort((a, b) => key(a) - key(b));
+}
+
+/**
+ * Sort an array in place by a string associated with that item.
+ * Strings will be sorted in alphabetic order.
+ * @param items The items to sort.
+ * @param key Returns the string associated with an item.
+ */
+export function sortByStringAscending<T>(items: T[], key: (T) => string) {
+  return items.sort((a, b) => key(a).localeCompare(key(b)));
+}
+
+/**
+ * Sort an array in place by a date associated with that item.
+ * Dates will be sorted from old to new.
+ * @param items The items to sort.
+ * @param key Returns the date associated with an item.
+ */
+export function sortByDateAscending<T>(items: T[], key: (T) => Date) {
+  return items.sort((a, b) =>  (key(b) as any) - (key(a) as any));
+}
+
+/**
+ * Converts a priority enum member to a number.
+ * @returns high -> 2, medium -> 1, low -> 0
+ */
+export function getNumberForPriority(priority: Priority): number {
+  switch (priority) {
+    case Priority.High:
+      return 2;
+    case Priority.Medium:
+      return 1;
+    case Priority.Low:
+      return 0;
+  }
+}