Moved DynamoDB items rendering to frontend and added ability to load more items

Author: Visual-Vincent

GuiStack/Controllers/DynamoDB/TablesController.cs

@@ -8,13 +8,18 @@
  */
 
 using System;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
 using System.Net;
 using System.Threading.Tasks;
 using Amazon.DynamoDBv2;
 using GuiStack.Extensions;
 using GuiStack.Models;
 using GuiStack.Repositories;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.WebUtilities;
+using Newtonsoft.Json;
 
 namespace GuiStack.Controllers.DynamoDB
 {
@@ -29,6 +34,40 @@ public TablesController(IDynamoDBRepository dynamodbRepository)
             this.dynamodbRepository = dynamodbRepository;
         }
 
+        private static DynamoDBItemModel DeserializeItem(string data)
+        {
+            using var resultStream = new MemoryStream();
+            using var reader = new StreamReader(resultStream);
+
+            using (var compressedStream = new MemoryStream(WebEncoders.Base64UrlDecode(data)))
+            using (var decompressionStream = new GZipStream(compressedStream, CompressionMode.Decompress))
+            {
+                decompressionStream.CopyTo(resultStream);
+            }
+
+            resultStream.Position = 0;
+
+            var json = reader.ReadToEnd();
+
+            // Utilizing Newtonsoft.Json as it better handles scalar types (string, int, etc.) when the target property is of type System.Object
+            // System.Text.Json deserializes these as JsonElement, which is not ideal
+            return JsonConvert.DeserializeObject<DynamoDBItemModel>(json);
+        }
+
+        private static string SerializeItem(DynamoDBItemModel model)
+        {
+            using var stream = new MemoryStream();
+
+            using (var compressionStream = new GZipStream(stream, CompressionLevel.Fastest))
+            using (var writer = new StreamWriter(compressionStream))
+            {
+                var json = JsonConvert.SerializeObject(model);
+                writer.Write(json);
+            }
+
+            return WebEncoders.Base64UrlEncode(stream.ToArray());
+        }
+
         private ActionResult HandleException(Exception ex)
         {
             if(ex == null)
@@ -85,6 +124,51 @@ public async Task<ActionResult> DeleteTable([FromRoute] string tableName)
             }
         }
 
+        [HttpGet("{tableName}")]
+        [Produces("application/json")]
+        public async Task<ActionResult> GetItems([FromRoute] string tableName, [FromQuery] int limit = 50, [FromQuery(Name = "lastEvaluatedKey")] string lastKey = null)
+        {
+            if(string.IsNullOrWhiteSpace(tableName) || limit < 1 || limit > 500)
+                return StatusCode((int)HttpStatusCode.BadRequest);
+
+            tableName = tableName.DecodeRouteParameter();
+
+            try
+            {
+                var lastKeyItem = !string.IsNullOrWhiteSpace(lastKey)
+                    ? DeserializeItem(lastKey)
+                    : null;
+
+                var table = await dynamodbRepository.GetTableInfoAsync(tableName);
+                var result = await dynamodbRepository.ScanAsync(tableName, limit, lastKeyItem);
+
+                var lastEvaluatedKey = result.LastEvaluatedKey != null
+                    ? SerializeItem(result.LastEvaluatedKey)
+                    : null;
+
+                var attributeNames = new[] { table.PartitionKey.Name, table.SortKey?.Name } // Ensure PartitionKey and SortKey are always first
+                    .Where(name => name != null)
+                    .Concat(result.Items // Join with the rest of the fields
+                        .SelectMany(item => item.Select(kvp => kvp.Key))
+                        .Where(name => name != table.PartitionKey.Name && (table.SortKey == null || name != table.SortKey.Name))
+                        .Distinct()
+                    )
+                    .ToArray();
+
+                return Json(new DynamoDBTableContentsModel() {
+                    PartitionKey = table.PartitionKey,
+                    SortKey = table.SortKey,
+                    AttributeNames = attributeNames,
+                    LastEvaluatedKey = lastEvaluatedKey,
+                    Items = result.Items
+                });
+            }
+            catch(Exception ex)
+            {
+                return HandleException(ex);
+            }
+        }
+
         [HttpPut("{tableName}")]
         [Consumes("application/json")]
         public async Task<ActionResult> PutItem([FromRoute] string tableName, [FromBody] DynamoDBItemModel model)

GuiStack/GuiStack.csproj

@@ -14,6 +14,7 @@
     <PackageReference Include="AWSSDK.SQS" Version="3.7.102.1" />
     <PackageReference Include="Google.Protobuf" Version="3.20.0" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation" Version="6.0.9" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
   </ItemGroup>
 
   <ItemGroup>

GuiStack/Licenses/Newtonsoft.Json.txt

@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2007 James Newton-King
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

GuiStack/Models/DynamoDBTableContentsModel.cs

@@ -0,0 +1,24 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ * 
+ * Copyright © Vincent Bengtsson & Contributors 2022-2024
+ * https://github.com/Visual-Vincent/GuiStack
+ */
+
+using System;
+using System.Collections.Generic;
+
+namespace GuiStack.Models
+{
+    public class DynamoDBTableContentsModel
+    {
+        public DynamoDBAttribute PartitionKey { get; set; }
+        public DynamoDBAttribute SortKey { get; set; }
+        public string[] AttributeNames { get; set; }
+        public string LastEvaluatedKey { get; set; }
+
+        public IEnumerable<DynamoDBItemModel> Items { get; set; }
+    }
+}

GuiStack/Models/DynamoDBTableScanResults.cs

@@ -0,0 +1,19 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ * 
+ * Copyright © Vincent Bengtsson & Contributors 2022-2024
+ * https://github.com/Visual-Vincent/GuiStack
+ */
+
+using System;
+
+namespace GuiStack.Models
+{
+    public class DynamoDBTableScanResults
+    {
+        public DynamoDBItemModel[] Items { get; set; }
+        public DynamoDBItemModel LastEvaluatedKey { get; set; }
+    }
+}

GuiStack/Pages/DynamoDB/Index.cshtml.cs

@@ -8,7 +8,6 @@
  */
 
 using System;
-using System.Threading.Tasks;
 using GuiStack.Repositories;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.RazorPages;
@@ -30,11 +29,5 @@ public IndexModel(IDynamoDBRepository dynamodbRepository)
         public void OnGet()
         {
         }
-
-        public async Task<IActionResult> OnGetRenderTableContentsPartial([FromQuery] int limit = 50)
-        {
-            var items = await DynamoDBRepository.ScanAsync(Table, limit);
-            return Partial("~/Pages/DynamoDB/_TableContentsPartial.cshtml", items);
-        }
     }
 }