From c50fe11529c8b0c479ccb3975e519b96f3ce736d Mon Sep 17 00:00:00 2001
From: Drake53 <49623303+Drake53@users.noreply.github.com>
Date: Sat, 2 Apr 2022 10:48:44 +0200
Subject: [PATCH] Fix pager for empty table.

---
 src/BlazorTable/Components/Pager.razor    | 12 ++++++------
 src/BlazorTable/Components/Table.razor.cs | 17 ++++++++++++-----
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/src/BlazorTable/Components/Pager.razor b/src/BlazorTable/Components/Pager.razor
index 8cd3332e..c4a3b238 100644
--- a/src/BlazorTable/Components/Pager.razor
+++ b/src/BlazorTable/Components/Pager.razor
@@ -34,17 +34,17 @@
                 </li>
             }
 
-            <li class="page-item @(Table.PageNumber == 0 ? "disabled": "")" @onclick="@(() => Table.FirstPageAsync())" title="@Localization["PagerFirst"]">
-                <a class="page-link" href="javascript:;" aria-disabled="@(Table.PageNumber == 0 ? "true": null)">@Localization["PagerFirst"]</a>
+            <li class="page-item @(Table.PageNumber <= 0 ? "disabled": "")" @onclick="@(() => Table.FirstPageAsync())" title="@Localization["PagerFirst"]">
+                <a class="page-link" href="javascript:;" aria-disabled="@(Table.PageNumber <= 0 ? "true": null)">@Localization["PagerFirst"]</a>
             </li>
-            <li class="page-item @(Table.PageNumber == 0 ? "disabled": "")" @onclick="@(() => Table.PreviousPageAsync())" title="@Localization["PagerPrevious"]">
-                <a class="page-link" href="javascript:;" aria-disabled="@(Table.PageNumber == 0 ? "true": null)">@Localization["PagerPrevious"]</a>
+            <li class="page-item @(Table.PageNumber <= 0 ? "disabled": "")" @onclick="@(() => Table.PreviousPageAsync())" title="@Localization["PagerPrevious"]">
+                <a class="page-link" href="javascript:;" aria-disabled="@(Table.PageNumber <= 0 ? "true": null)">@Localization["PagerPrevious"]</a>
             </li>
             <li class="page-item @(Table.PageNumber + 1 < Table.TotalPages ? "" : "disabled")" @onclick="@(() => Table.NextPageAsync())" title="@Localization["PagerNext"]">
                 <a class="page-link" href="javascript:;" aria-disabled="@(Table.PageNumber + 1 < Table.TotalPages ? null: "true")">@Localization["PagerNext"]</a>
             </li>
-            <li class="page-item @(Table.PageNumber + 1 != Table.TotalPages ? "" : "disabled")" @onclick="@(() => Table.LastPageAsync())" title="@Localization["PagerLast"]">
-                <a class="page-link" href="javascript:;" aria-disabled="@(Table.PageNumber + 1 != Table.TotalPages ? null : "true")">@Localization["PagerLast"]</a>
+            <li class="page-item @(Table.PageNumber + 1 < Table.TotalPages ? "" : "disabled")" @onclick="@(() => Table.LastPageAsync())" title="@Localization["PagerLast"]">
+                <a class="page-link" href="javascript:;" aria-disabled="@(Table.PageNumber + 1 < Table.TotalPages ? null : "true")">@Localization["PagerLast"]</a>
             </li>
         </ul>
     </div>
diff --git a/src/BlazorTable/Components/Table.razor.cs b/src/BlazorTable/Components/Table.razor.cs
index 57c959c3..fa64b7d9 100644
--- a/src/BlazorTable/Components/Table.razor.cs
+++ b/src/BlazorTable/Components/Table.razor.cs
@@ -186,10 +186,14 @@ private IEnumerable<TableItem> GetData()
             }
 
             // if the current page is filtered out, we should go back to a page that exists
-            if (PageNumber > TotalPages)
+            if (PageNumber >= TotalPages)
             {
                 PageNumber = TotalPages - 1;
             }
+            else if (PageNumber < 0 && TotalPages > 0)
+            {
+                PageNumber = 0;
+            }
 
             // if PageSize is zero, we return all rows and no paging
             return PageSize <= 0 ? ItemsQueryable.ToList() : ItemsQueryable.Skip(PageNumber * PageSize).Take(PageSize).ToList();
@@ -292,7 +296,7 @@ public void RemoveColumn(IColumn<TableItem> column)
         /// </summary>
         public async Task FirstPageAsync()
         {
-            if (PageNumber != 0)
+            if (PageNumber > 0)
             {
                 PageNumber = 0;
                 detailsViewOpen.Clear();
@@ -331,9 +335,12 @@ public async Task PreviousPageAsync()
         /// </summary>
         public async Task LastPageAsync()
         {
-            PageNumber = TotalPages - 1;
-            detailsViewOpen.Clear();
-            await UpdateAsync().ConfigureAwait(false);
+            if (PageNumber + 1 < TotalPages)
+            {
+                PageNumber = TotalPages - 1;
+                detailsViewOpen.Clear();
+                await UpdateAsync().ConfigureAwait(false);
+            }
         }
 
         /// <summary>