feat(VisualRecognitionV4): add support for download model file

Author: mamoonraja

Scripts/Services/VisualRecognition/V4/Model/ImageDetails.cs

@@ -1,5 +1,5 @@
 /**
-* Copyright 2018, 2019 IBM Corp. All Rights Reserved.
+* (C) Copyright IBM Corp. 2018, 2020.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -52,7 +52,7 @@ public class ImageDetails
         [JsonProperty("dimensions", NullValueHandling = NullValueHandling.Ignore)]
         public ImageDimensions Dimensions { get; set; }
         /// <summary>
-        /// Gets or Sets Errors
+        /// Details about the errors.
         /// </summary>
         [JsonProperty("errors", NullValueHandling = NullValueHandling.Ignore)]
         public List<Error> Errors { get; set; }

Scripts/Services/VisualRecognition/V4/Model/ObjectTrainingStatus.cs

@@ -45,6 +45,11 @@ public class ObjectTrainingStatus
         [JsonProperty("latest_failed", NullValueHandling = NullValueHandling.Ignore)]
         public bool? LatestFailed { get; set; }
         /// <summary>
+        /// Whether the model can be downloaded after the training status is `ready`.
+        /// </summary>
+        [JsonProperty("rscnn_ready", NullValueHandling = NullValueHandling.Ignore)]
+        public bool? RscnnReady { get; set; }
+        /// <summary>
         /// Details about the training. If training is in progress, includes information about the status. If training
         /// is not in progress, includes a success message or information about why training failed.
         /// </summary>

Scripts/Services/VisualRecognition/V4/VisualRecognitionService.cs

@@ -575,6 +575,84 @@ private void OnDeleteCollectionResponse(RESTConnector.Request req, RESTConnector
                 ((RequestObject<object>)req).Callback(response, resp.Error);
         }
         /// <summary>
+        /// Get a model.
+        ///
+        /// Download a model that you can deploy to detect objects in images. The collection must include a generated
+        /// model, which is indicated in the response for the collection details as `"rscnn_ready": true`. If the value
+        /// is `false`, train or retrain the collection to generate the model.
+        ///
+        /// Currently, the model format is specific to Android apps. For more information about how to deploy the model
+        /// to your app, see the [Watson Visual Recognition on Android](https://github.com/matt-ny/rscnn) project in
+        /// GitHub.
+        /// </summary>
+        /// <param name="callback">The callback function that is invoked when the operation completes.</param>
+        /// <param name="collectionId">The identifier of the collection.</param>
+        /// <param name="feature">The feature for the model.</param>
+        /// <param name="modelFormat">The format of the returned model.</param>
+        /// <returns><see cref="byte[]" />byte[]</returns>
+        public bool GetModelFile(Callback<byte[]> callback, string collectionId, string feature, string modelFormat)
+        {
+            if (callback == null)
+                throw new ArgumentNullException("`callback` is required for `GetModelFile`");
+            if (string.IsNullOrEmpty(collectionId))
+                throw new ArgumentNullException("`collectionId` is required for `GetModelFile`");
+            if (string.IsNullOrEmpty(feature))
+                throw new ArgumentNullException("`feature` is required for `GetModelFile`");
+            if (string.IsNullOrEmpty(modelFormat))
+                throw new ArgumentNullException("`modelFormat` is required for `GetModelFile`");
+
+            RequestObject<byte[]> req = new RequestObject<byte[]>
+            {
+                Callback = callback,
+                HttpMethod = UnityWebRequest.kHttpVerbGET,
+                DisableSslVerification = DisableSslVerification
+            };
+
+            foreach (KeyValuePair<string, string> kvp in customRequestHeaders)
+            {
+                req.Headers.Add(kvp.Key, kvp.Value);
+            }
+
+            ClearCustomRequestHeaders();
+
+            foreach (KeyValuePair<string, string> kvp in Common.GetSdkHeaders("watson_vision_combined", "V4", "GetModelFile"))
+            {
+                req.Headers.Add(kvp.Key, kvp.Value);
+            }
+
+            req.Parameters["version"] = VersionDate;
+            if (!string.IsNullOrEmpty(feature))
+            {
+                req.Parameters["feature"] = feature;
+            }
+            if (!string.IsNullOrEmpty(modelFormat))
+            {
+                req.Parameters["model_format"] = modelFormat;
+            }
+
+            req.OnResponse = OnGetModelFileResponse;
+
+            Connector.URL = GetServiceUrl() + string.Format("/v4/collections/{0}/model", collectionId);
+            Authenticator.Authenticate(Connector);
+
+            return Connector.Send(req);
+        }
+
+        private void OnGetModelFileResponse(RESTConnector.Request req, RESTConnector.Response resp)
+        {
+            DetailedResponse<byte[]> response = new DetailedResponse<byte[]>();
+            foreach (KeyValuePair<string, string> kvp in resp.Headers)
+            {
+                response.Headers.Add(kvp.Key, kvp.Value);
+            }
+            response.StatusCode = resp.HttpResponseCode;
+
+            response.Result = resp.Data;
+
+            if (((RequestObject<byte[]>)req).Callback != null)
+                ((RequestObject<byte[]>)req).Callback(response, resp.Error);
+        }
+        /// <summary>
         /// Add images.
         ///
         /// Add images to a collection by URL, by file, or both.