Downloading attachments from rally using C# and .NET

Question

My ultimate goal in the script I am writing is to download all attachments from rally. I was able to successfully connect to the server, make a request for all attachments in a workspace, and finally, iterate through to retrieve the content of each attachment. This yields a dynamicJsonObject of the AttachmentContent. Being new to any API as well C# and .NET, I am now stuck. I cannot figure out a way to access and download the content of this object to a file on my computer. The line I have commented below is where I am currently getting an error and I am stuck. Any help would be greatly appreciated.

P.S. Here is my main method:

static void Main(string[] args)
    {
        RallyRestApi restApi = new RallyRestApi("[email protected]", "password", "https://rally1.rallydev.com", "1.43");
        Request request = new Request("attachment");
        request.Workspace = "/workspace/186282018";
        request.Fetch = new List<string>() { "Name", "Artifact", "Content", "ContentType" };
        request.Query = new Query("");
        QueryResult queryResult = restApi.Query(request);
        int count = 0;
        foreach (var result in queryResult.Results)
        {     
            DynamicJsonObject content = result["Content"];
            //var binContent = content["Content"];
            count++;
        }
        Console.WriteLine(count);
        Console.ReadLine();
    }

Answer 1

Here's an example that simply writes the content bytes to a File and skips the mime-type checking:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using Rally.RestApi;
using Rally.RestApi.Response;

namespace RestExample_DownloadAttachment
{
    class Program
    {
        static void Main(string[] args)
        {
             //Initialize the REST API
            RallyRestApi restApi;

            // Rally parameters
            String userName = "[email protected]";
            String userPassword = "topsecret";
            String rallyURL = "https://rally1.rallydev.com";
            String wsapiVersion = "1.43";

            restApi = new RallyRestApi(
                userName,
                userPassword,
                rallyURL,
                wsapiVersion
            );


            //Set our Workspace and Project scopings
            String workspaceRef = "/workspace/12345678910";
            String projectRef = "/project/12345678911";
            bool projectScopingUp = false;
            bool projectScopingDown = true;

            // Find User Story that we want to pull attachment from

            // Tee up Story Request
            Request storyRequest = new Request("hierarchicalrequirement");
            storyRequest.Workspace = workspaceRef;
            storyRequest.Project = projectRef;
            storyRequest.ProjectScopeDown = projectScopingDown;
            storyRequest.ProjectScopeUp = projectScopingUp;

            // Fields to Fetch
            storyRequest.Fetch = new List<string>()
                {
                    "Name",
                    "FormattedID",
                    "Attachments"
                };

            // Add a query
            storyRequest.Query = new Query("FormattedID", Query.Operator.Equals, "US163");

            // Query Rally for the Story
            QueryResult queryResult = restApi.Query(storyRequest);

            // Pull reference off of Story fetch
            DynamicJsonObject storyObject = queryResult.Results.First();
            String storyReference = storyObject["_ref"];
            Console.WriteLine("Looking for attachments off of Story: " + storyReference);

            // Grab the Attachments collection
            var storyAttachments = storyObject["Attachments"];
            // Let's download the first attachment for starters
            var myAttachmentFromStory = storyAttachments[0];
            // Pull the ref
            String myAttachmentRef = myAttachmentFromStory["_ref"];
            Console.WriteLine("Found Attachment: " + myAttachmentRef);

            // Fetch fields for the Attachment
            string[] attachmentFetch = { "ObjectID", "Name", "Content", "ContentType", "Size"};

            // Now query for the attachment
            DynamicJsonObject attachmentObject = restApi.GetByReference(myAttachmentRef, "true");

            // Grab the AttachmentContent
            DynamicJsonObject attachmentContentFromAttachment = attachmentObject["Content"];
            String attachmentContentRef = attachmentContentFromAttachment["_ref"];

            // Lastly pull the content
            // Fetch fields for the Attachment
            string[] attachmentContentFetch = { "ObjectID", "Content" };

            // Now query for the attachment
            Console.WriteLine("Querying for Content...");
            DynamicJsonObject attachmentContentObject = restApi.GetByReference(attachmentContentRef, "true");
            Console.WriteLine("AttachmentContent: " + attachmentObject["_ref"]);

            String base64EncodedContent = attachmentContentObject["Content"];

            // File information
            String attachmentSavePath = "C:\\Users\\username\\";
            String attachmentFileName = attachmentObject["Name"];
            String fullAttachmentFile = attachmentSavePath + attachmentFileName; 

            // Determine attachment Content mime-type
            String attachmentContentType = attachmentObject["ContentType"];

            try {

                // Output base64 content to File
                Console.WriteLine("Saving base64 AttachmentContent String to File.");

                File.WriteAllBytes(@fullAttachmentFile, Convert.FromBase64String(base64EncodedContent));
            }
            catch (Exception e)
            {
                Console.WriteLine("Unhandled exception occurred while writing file: " + e.StackTrace);
                Console.WriteLine(e.Message);
            }

            Console.ReadKey();
        }
    }
}