Microsoft Bot Framework: Getting Started – Bot sends an attachment file to the end user

2024-01-17

In the previous article we saw how to send a file to the Bot. There will be cases where the Bot may send some files to the User. For example, if you are building a Payment Bot once the payment is complete the Bot would send back the receipt to the user. This article demonstrates the Bot sending a file to the end user. File exchanges between the Bot and the end user is an important concept and we will be using it when we are building Intelligent Bots that work on files using Cognitive Services in the future articles.

Prerequisites

Before deep diving into this article I would strongly recommend you to go through all the previous articles of this series.
Microsoft Bot Framework : Getting Started - Building the first Hello Bot
Microsoft Bot Framework: Getting Started – Making the Bot Intelligent using Text Analytics Sentiment API from Microsoft Cognitive Services
Microsoft Bot Framework: Getting Started – Understanding Dialogs and Maintaining states between conversations
Microsoft Bot Framework: Getting Started – Sending a File to the Bot
Here in this article we will not be focusing on the basic concepts of Bot Framework. We will concentrate here on how the Bot can send file to the user.

Sending Attachment

Bot sending file to the user can be achieved very easily. The steps demonstrated to achieve this would be one of the easiest steps among all the articles in this series. An Attachment object has to be created and added to the message Activity object. The Attachment object should contain the file type and url.

Step 1

Open Visual Studio and create a project of type Bot Application.

Step 2

Go to Controllers\MessagesController.cs and replace Post method with below.

public async Task<HttpResponseMessage> Post([FromBody]Activity activity)
       {
           if (activity.Type == ActivityTypes.Message)
           {
               //File that Bot will send to the user. You can keep a file in your local directory 
               //and can paste complete path here.
               string filePath = @"C:\BotDirectory\Image\IMG_4821.jpg";
               //Convert to Uri. Bot can send absolute Uri path only as attachment.
               var uri = new  System.Uri(filePath);
               ConnectorClient connector = new  ConnectorClient(new  Uri(activity.ServiceUrl));
               Activity message = activity.CreateReply("Please check the image you have requested for.");
               //Create attachment
               Attachment attachment = new  Attachment();
               attachment.ContentType = "image/jpg";
               //Content Url for the attachment can only be Absolute Uri
               attachment.ContentUrl = uri.AbsoluteUri;
               //Add attachment to the message
               message.Attachments.Add(attachment);
               //Send Reply message along with the attachment
               await connector.Conversations.ReplyToActivityAsync(message);
           }
           else
           {
               HandleSystemMessage(activity);
           }
           var response = Request.CreateResponse(HttpStatusCode.OK);
           return response;
       }

Step 3

Place a file in a local folder. Bot will pick up this file and send to the user. Here I have kept my photo in a local folder that the Bot will send across to the user.

http://i.imgur.com/P4yXFBW.jpg

Step 4

Build the solution and run. The service starts up.

http://i.imgur.com/RsGlpFQ.jpg

Step 5

Open Bot framework emulator and communicate with Bot. User sends Hi to the Bot and the Bot replies back with the image.

http://i.imgur.com/fEAIZvV.jpg

Source Code

This solution is built using Visual Studio 2017 Community Edition. You can get the source from GitHub repository here.

Next Steps

Watch out this step for next set of articles in this series.

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