Add Nested example page to basic sample

Author: mrahhal

samples/Basic/Models/User.cs

@@ -10,5 +10,15 @@ public class User
 		public string Name { get; set; }
 
 		public DateTime Created { get; set; }
+
+		public UserDetails Details { get; set; }
+	}
+
+	[Index(nameof(Created))]
+	public class UserDetails
+	{
+		public int Id { get; set; }
+
+		public DateTime Created { get; set; }
 	}
 }

samples/Basic/Pages/Nested.cshtml

@@ -0,0 +1,31 @@
+@page
+@model NestedModel
+
+<div class="text-center">
+    @if (Model.Users.Any())
+    {
+        <div class="users">
+            @foreach (var user in Model.Users)
+            {
+                <div class="user">
+                    @user.Name (@user.Details.Created.ToLongDateString())
+                </div>
+            }
+        </div>
+
+        <div class="mt-3" style="text-align: center">
+            (@Model.Count items) (@Model.Elapsed | total with prev/next: @Model.ElapsedTotal)
+        </div>
+
+        <div class="pagination mt-3">
+            <a asp-page="/Nested" asp-route-first="@true" disabled="@(!Model.HasPrevious ? "disabled" : null)">First</a>
+            <a asp-page="/Nested" asp-route-before="@Model.Users.First().Id" disabled="@(!Model.HasPrevious ? "disabled" : null)">Previous</a>
+            <a asp-page="/Nested" asp-route-after="@Model.Users.Last().Id" disabled="@(!Model.HasNext ? "disabled" : null)">Next</a>
+            <a asp-page="/Nested" asp-route-last="@true" disabled="@(!Model.HasNext ? "disabled" : null)">Last</a>
+        </div>
+    }
+    else
+    {
+        <div>Nothing</div>
+    }
+</div>

samples/Basic/Pages/Nested.cshtml.cs

@@ -0,0 +1,98 @@
+using System.Diagnostics;
+using Basic.Models;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using Microsoft.EntityFrameworkCore;
+using MR.EntityFrameworkCore.KeysetPagination;
+
+namespace Basic.Pages
+{
+	public class NestedModel : PageModel
+	{
+		private readonly AppDbContext _dbContext;
+
+		public NestedModel(
+			AppDbContext dbContext)
+		{
+			_dbContext = dbContext;
+		}
+
+		public int Count { get; set; }
+
+		public List<User> Users { get; set; }
+
+		public bool HasPrevious { get; set; }
+
+		public bool HasNext { get; set; }
+
+		public string Elapsed { get; set; }
+
+		public string ElapsedTotal { get; set; }
+
+		public async Task OnGet(int? after, int? before, bool first = false, bool last = false)
+		{
+			var size = 20;
+
+			var keysetBuilderAction = (KeysetPaginationBuilder<User> b) =>
+			{
+				b.Descending(x => x.Details.Created);
+			};
+
+			var sw = Stopwatch.StartNew();
+
+			var query = _dbContext.Users.AsQueryable();
+			Count = await query.CountAsync();
+			KeysetPaginationContext<User> keysetContext;
+			if (first)
+			{
+				keysetContext = query.KeysetPaginate(keysetBuilderAction, KeysetPaginationDirection.Forward);
+				Users = await keysetContext.Query
+					.Include(x => x.Details)
+					.Take(size)
+					.ToListAsync();
+			}
+			else if (last)
+			{
+				keysetContext = query.KeysetPaginate(keysetBuilderAction, KeysetPaginationDirection.Backward);
+				Users = await keysetContext.Query
+					.Include(x => x.Details)
+					.Take(size)
+					.ToListAsync();
+			}
+			else if (after != null)
+			{
+				var reference = await _dbContext.Users.Include(x => x.Details).FirstOrDefaultAsync(x => x.Id == after.Value);
+				keysetContext = query.KeysetPaginate(keysetBuilderAction, KeysetPaginationDirection.Forward, reference);
+				Users = await keysetContext.Query
+					.Include(x => x.Details)
+					.Take(size)
+					.ToListAsync();
+			}
+			else if (before != null)
+			{
+				var reference = await _dbContext.Users.Include(x => x.Details).FirstOrDefaultAsync(x => x.Id == before.Value);
+				keysetContext = query.KeysetPaginate(keysetBuilderAction, KeysetPaginationDirection.Backward, reference);
+				Users = await keysetContext.Query
+					.Include(x => x.Details)
+					.Take(size)
+					.ToListAsync();
+			}
+			else
+			{
+				keysetContext = query.KeysetPaginate(keysetBuilderAction);
+				Users = await keysetContext.Query
+					.Include(x => x.Details)
+					.Take(size)
+					.ToListAsync();
+			}
+
+			keysetContext.EnsureCorrectOrder(Users);
+
+			Elapsed = sw.ElapsedMilliseconds.ToString();
+
+			HasPrevious = await keysetContext.HasPreviousAsync(Users);
+			HasNext = await keysetContext.HasNextAsync(Users);
+
+			ElapsedTotal = sw.ElapsedMilliseconds.ToString();
+		}
+	}
+}

samples/Basic/Pages/Shared/_Layout.cshtml

@@ -24,6 +24,9 @@
                         <li class="nav-item">
                             <a class="nav-link text-dark" asp-area="" asp-page="/Example2">Example 2</a>
                         </li>
+                        <li class="nav-item">
+                            <a class="nav-link text-dark" asp-area="" asp-page="/Nested">Nested</a>
+                        </li>
                     </ul>
                 </div>
             </div>

samples/Basic/Startup.cs

@@ -41,6 +41,10 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
 						Id = i,
 						Name = i.ToString(),
 						Created = created,
+						Details = new UserDetails
+						{
+							Created = created,
+						},
 					});
 				}
 				_dbContext.AddRange(users);