Add Api helper methods for POST requests (#9134)

* Add Api helper methods for POST requests

* Support json serializer setting for json requests

* Minor changes and cleanup

* Make ApiConnection disposable

Author: jhonabreul

Api/Api.cs

@@ -207,6 +207,30 @@ public RestResponse AddProjectFile(int projectId, string name, string content)
             return result;
         }
 
+        /// <summary>
+        /// Makes a simple POST request to the specified endpoint with the given payload
+        /// </summary>
+        protected bool TryPost<T>(string endpoint, IEnumerable<KeyValuePair<string, string>> payload, out T result,
+            ApiConnection apiConnection = null, TimeSpan? timeout = null)
+            where T : RestResponse
+        {
+            using var request = ApiUtils.CreatePostRequest(endpoint, payload);
+
+            return (apiConnection ?? ApiConnection).TryRequest(request, out result, timeout);
+        }
+
+        /// <summary>
+        /// Makes a simple POST request to the specified endpoint with the given payload
+        /// </summary>
+        protected bool TryJsonPost<T>(string endpoint, object payload, out T result,
+            ApiConnection apiConnection = null, JsonSerializerSettings jsonSerializerSettings = null, TimeSpan? timeout = null)
+            where T : RestResponse
+        {
+            using var request = ApiUtils.CreateJsonPostRequest(endpoint, payload, jsonSerializerSettings);
+
+            return (apiConnection ?? ApiConnection).TryRequest(request, out result, timeout);
+        }
+
 
         /// <summary>
         /// Update the name of a file
@@ -1487,6 +1511,7 @@ public virtual void Dispose()
                 }
             }
             _clientPool.DisposeSafely();
+            ApiConnection?.DisposeSafely();
         }
 
         /// <summary>

Api/ApiConnection.cs

@@ -30,7 +30,7 @@ namespace QuantConnect.Api
     /// <summary>
     /// API Connection and Hash Manager
     /// </summary>
-    public class ApiConnection
+    public class ApiConnection : IDisposable
     {
         /// <summary>
         /// Authorized client to use for requests.
@@ -118,6 +118,14 @@ public void SetClient(string baseUrl, Dictionary<string, string> defaultHeaders
             }
         }
 
+        /// <summary>
+        /// Disposes of the HTTP client
+        /// </summary>
+        public void Dispose()
+        {
+            _httpClient.Dispose();
+        }
+
         /// <summary>
         /// Place a secure request and get back an object of type T.
         /// </summary>

Api/ApiUtils.cs

@@ -0,0 +1,65 @@
+/*
+ * QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
+ * Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+
+using System.Net.Http;
+using System.Collections.Generic;
+using Newtonsoft.Json;
+using System.Net.Http.Headers;
+using System.Net.Mime;
+
+namespace QuantConnect.Api
+{
+    /// <summary>
+    /// API utility methods
+    /// </summary>
+    public static class ApiUtils
+    {
+        /// <summary>
+        /// Creates a POST <see cref="HttpRequestMessage"/> with the specified endpoint and payload as form url encoded content.
+        /// </summary>
+        /// <param name="endpoint">The request endpoint</param>
+        /// <param name="payload">The request payload</param>
+        /// <returns>The POST request</returns>
+        public static HttpRequestMessage CreatePostRequest(string endpoint, IEnumerable<KeyValuePair<string, string>> payload = null)
+        {
+            var request = new HttpRequestMessage(HttpMethod.Post, endpoint);
+            if (payload != null)
+            {
+                request.Content = new FormUrlEncodedContent(payload);
+            }
+
+            return request;
+        }
+
+        /// <summary>
+        /// Creates a POST <see cref="HttpRequestMessage"/> with the specified endpoint and payload as json body
+        /// </summary>
+        /// <param name="endpoint">The request endpoint</param>
+        /// <param name="payload">The request payload</param>
+        /// <param name="jsonSerializerSettings">Settings for the json serializer</param>
+        /// <returns>The POST request</returns>
+        public static HttpRequestMessage CreateJsonPostRequest(string endpoint, object payload = null, JsonSerializerSettings jsonSerializerSettings = null)
+        {
+            var request = new HttpRequestMessage(HttpMethod.Post, endpoint);
+            if (payload != null)
+            {
+                request.Content = new StringContent(JsonConvert.SerializeObject(payload, jsonSerializerSettings),
+                    new MediaTypeHeaderValue(MediaTypeNames.Application.Json));
+            }
+
+            return request;
+        }
+    }
+}

Brokerages/Authentication/OAuthTokenHandler.cs

@@ -17,6 +17,7 @@
 using RestSharp;
 using QuantConnect.Api;
 using System.Threading;
+using QuantConnect.Util;
 
 namespace QuantConnect.Brokerages.Authentication
 {
@@ -50,6 +51,8 @@ public sealed class OAuthTokenHandler<TRequest, TResponse> : TokenHandler
         /// </summary>
         private TokenCredentials _tokenCredentials;
 
+        private bool _disposed;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="OAuthTokenHandler{TRequest, TResponse}"/> class.
         /// </summary>
@@ -96,5 +99,19 @@ public override TokenCredentials GetAccessToken(CancellationToken cancellationTo
                 throw new InvalidOperationException($"{nameof(OAuthTokenHandler<TRequest, TResponse>)}.{nameof(GetAccessToken)}: {ex.Message}");
             }
         }
+
+        /// <summary>
+        /// Disposes of resources
+        /// </summary>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && !_disposed)
+            {
+                _disposed = true;
+                _apiClient?.DisposeSafely();
+            }
+
+            base.Dispose(disposing);
+        }
     }
 }

Tests/Api/ApiTests.cs

@@ -34,7 +34,7 @@ public class ApiTest : ApiTestBase
         [Test, Explicit("Requires configured api access")]
         public void ApiConnectionWillAuthenticate_ValidCredentials_Successfully()
         {
-            var connection = new ApiConnection(TestAccount, TestToken);
+            using var connection = new ApiConnection(TestAccount, TestToken);
             Assert.IsTrue(connection.Connected);
         }
 
@@ -55,7 +55,7 @@ public void ApiWillAuthenticate_ValidCredentials_Successfully()
         [Test]
         public void ApiConnectionWillAuthenticate_InvalidCredentials_Unsuccessfully()
         {
-            var connection = new ApiConnection(TestAccount, "");
+            using var connection = new ApiConnection(TestAccount, "");
             Assert.IsFalse(connection.Connected);
         }