Merge pull request #48 from crupest/user-details

Add user details.

1 files changed, 30 insertions, 0 deletions

diff --git a/Timeline/Services/DatabaseExtensions.cs b/Timeline/Services/DatabaseExtensions.cs
new file mode 100644
index 00000000..a37cf05b
--- /dev/null
+++ b/Timeline/Services/DatabaseExtensions.cs
@@ -0,0 +1,30 @@
+using Microsoft.EntityFrameworkCore;

+using System;

+using System.Collections.Generic;

+using System.Linq;

+using System.Threading.Tasks;

+using Timeline.Entities;

+

+namespace Timeline.Services

+{

+    public static class DatabaseExtensions

+    {

+        /// <summary>

+        /// Check the existence and get the id of the user.

+        /// </summary>

+        /// <param name="username">The username of the user.</param>

+        /// <returns>The user id.</returns>

+        /// <exception cref="ArgumentException">Thrown if <paramref name="username"/> is null or empty.</exception>

+        /// <exception cref="UserNotExistException">Thrown if user does not exist.</exception>

+        public static async Task<long> CheckAndGetUser(DbSet<User> userDbSet, string username)

+        {

+            if (string.IsNullOrEmpty(username))

+                throw new ArgumentException("Username is null or empty.", nameof(username));

+

+            var userId = await userDbSet.Where(u => u.Name == username).Select(u => u.Id).SingleOrDefaultAsync();

+            if (userId == 0)

+                throw new UserNotExistException(username);

+            return userId;

+        }

+    }

+}