Bot framework : Detect when the user uploaded a file

Question

I'm trying to create a form in my bot in which the user has to upload a file along with other text inputs. For that i made a ReceiveAttachmentDialog in which it'll verify if the user has uploaded a file or not, the problem is that i can't figure how to detect when the user uploaded a file and thus lunch the ReceiveAttachmentDialo.

The forDialog is this :

[Serializable]
    public class FraisDialog : IDialog<object>
    {

        public async Task StartAsync(IDialogContext context)
        {
            // Root dialog initiates and waits for the next message from the user. 
            // When a message arrives, call MessageReceivedAsync.

            var replyMessage = context.MakeMessage();


            replyMessage.Attachments = new List<Connector.Attachment> { CreateAdaptiveCardwithEntry() };
            await context.PostAsync("Veuillez compléter le formulaire ci-dessous");
            await context.PostAsync(replyMessage, CancellationToken.None);
            context.Wait(this.MessageReceivedAsync);
        }


        public virtual async Task MessageReceivedAsync(IDialogContext context, IAwaitable<IMessageActivity> result)
        {

            context.Wait(MessageReceivedAsync);
            var message = await result;

            if (message.Value != null)
            {
                // Got an Action Submit
                dynamic value = message.Value;
                string submitType = value.Type.ToString();
                switch (submitType)
                {
                    case "SaveFunction":
                        if (value.titre == "")
                        {
                            await context.PostAsync("Veuillez compléter tous les paramètres du formulaire \n");
                        }
                        else
                        {
                            await context.PostAsync($"Vous avez saisie les paramètres suivants : \n titre :  {value.titre} \n date : {value.date} \n montant :  {value.montant}");

                           context.Done<string>(null);
                       }
                       return;
                }
            }
       }

        public Connector.Attachment CreateAdaptiveCardwithEntry()
        {
            var submitActionData = JObject.Parse("{ \"Type\": \"SaveFunction\" }");
            var card = new AdaptiveCard()
            {

                Body = new List<CardElement>()
                {  
                    // Hotels Search form  

                    new TextBlock() { Text = "Titre de la note des frais" },
                    new TextInput()
                    {
                        Id = "titre",
                        Speak = "<s>Veuillez saisir le titre</s>",
                        Placeholder = "Veuillez saisir le titre",
                        Style = TextInputStyle.Text
                    },
                    new TextBlock() { Text = "Date de la note des frais" },
                    new DateInput()
                    {
                        Id = "date",
                        Placeholder ="Veuillez saisir la Date de la note des frais"
                    },

                    new TextBlock() { Text = "Montant en euros de la note de frais" },
                    new NumberInput()
                    {
                        Id = "montant",
                        Speak = "<s>Veuillez saisir le Montant en euros de la note de frais</s>",
                        Placeholder = "Veuillez saisir le Montant de la note de frais",

                    },

                },

                Actions = new List<ActionBase>()
                {
                    new SubmitAction()
                    {
                       Title = "Envoyer",
                       Speak = "<s>Envoyer</s>",
                       DataJson = submitActionData.ToString()

                    }
                }
            };

            Connector.Attachment attachment = new Connector.Attachment()
            {
                ContentType = AdaptiveCard.ContentType,
                Content = card
            };
            return attachment;
        }
    }

My question is how i detect when the user has uploaded a file ? and where exactly should i put await context.Forward(new ReceiveAttachmentDialog(), this.ResumeAfterRecieveDialog, context.Activity, CancellationToken.None);

Answer 1

I suggest you use FormFlow if you aren't already, and check the sample located here and ImagesForm.cs for the form itself.

using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.Serialization;
using System.Threading.Tasks;

using Microsoft.Bot.Builder.Dialogs;
using Microsoft.Bot.Builder.FormFlow;
using Microsoft.Bot.Builder.FormFlow.Advanced;
using Microsoft.Bot.Connector;

namespace Microsoft.Bot.Sample.FormFlowAttachmentsBot
{
    [Serializable]
    public class MyAwaitableImage : AwaitableAttachment
    {
        // Mandatory: you should have this ctor as it is used by the recognizer
        public MyAwaitableImage(Attachment source) : base(source) { }

        // Mandatory: you should have this serialization ctor as well & call base
        protected MyAwaitableImage(SerializationInfo info, StreamingContext context) : base(info, context) { }

        // Optional: here you can check for content-type for ex 'image/png' or other..
        public override async Task<ValidateResult> ValidateAsync<T>(IField<T> field, T state)
        {
            var result = await base.ValidateAsync(field, state);

            if (result.IsValid)
            {
                var isValidForMe = this.Attachment.ContentType.ToLowerInvariant().Contains("image/png");

                if (!isValidForMe)
                {
                    result.IsValid = false;
                    result.Feedback = $"Hey, dude! Provide a proper 'image/png' attachment, not any file on your computer like '{this.Attachment.Name}'!";
                }
            }

            return result;
        }

        // Optional: here you can provide additional or override custom help text completely..
        public override string ProvideHelp<T>(IField<T> field)
        {
            var help = base.ProvideHelp(field);

            help += $"{Environment.NewLine}- Only 'image/png' can be attached to this field.";

            return help;
        }

        // Optional: here you can define your custom logic to get the attachment data or add custom logic to check it, etc..
        protected override async Task<Stream> ResolveFromSourceAsync(Attachment source)
        {
            var result = await base.ResolveFromSourceAsync(source);

            // You can apply custom logic to result or avoid calling base and resolve it yourself
            // For ex. if you plan to use your instance several times you can return a MemoryStream instead

            return result;
        }
    }

    [Serializable]
    public class ImagesForm
    {
        // Attachment field has no validation - any attachment would work
        public AwaitableAttachment BestImage;

        // Attachment field is optional - validation is done through AttachmentContentTypeValidator usage
        [Optional]
        [AttachmentContentTypeValidator(ContentType = "png")]
        public AwaitableAttachment SecondaryImage;

        // You can use an AwaitableAttachment descendant in order to have your own custom logic
        public IEnumerable<MyAwaitableImage> CustomImages;

        public static IForm<ImagesForm> BuildForm()
        {
            OnCompletionAsyncDelegate<ImagesForm> onFormCompleted = async (context, state) =>
            {
                await context.PostAsync("Here is a summary of the data you submitted:");

                var bestImageSize = await RetrieveAttachmentSizeAsync(state.BestImage);
                await context.PostAsync($"Your best image is '{state.BestImage.Attachment.Name}' - Type: {state.BestImage.Attachment.ContentType} - Size: {bestImageSize} bytes");

                if (state.SecondaryImage != null)
                {
                    var secondaryImageSize = await RetrieveAttachmentSizeAsync(state.SecondaryImage);
                    await context.PostAsync($"Your secondary image is '{state.SecondaryImage.Attachment.Name}' - Type: {state.SecondaryImage.Attachment.ContentType} - Size: {secondaryImageSize} bytes");
                }
                else
                {
                    await context.PostAsync($"You didn't submit a secondary image");
                }

                var customImagesTextInfo = string.Empty;
                foreach (var image in state.CustomImages)
                {
                    var imgSize = await RetrieveAttachmentSizeAsync(image);
                    customImagesTextInfo += $"{Environment.NewLine}- Name: '{image.Attachment.Name}' - Type: {image.Attachment.ContentType} - Size: {imgSize} bytes";
                }

                await context.PostAsync($"Here is the info of custom images you submitted: {customImagesTextInfo}");
            };

            // Form localization is done by setting the thread culture
            System.Threading.Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo("en-us");

            return new FormBuilder<ImagesForm>()
                .Message("Welcome, please submit all required images")
                .OnCompletion(onFormCompleted)
                .Build();
        }

        private static async Task<long> RetrieveAttachmentSizeAsync(AwaitableAttachment attachment)
        {
            var stream = await attachment;
            return stream.Length;
        }
    }
}

Answer 2

As @Ali Heikal said formflow is a completely valid option for you. Another option without using formflow is to just check if the Activity the bot recieved from the user has any Attachments . Activity.Attachments is a IList<Attachment> which will contain any file the user has uploaded to the bot. So simply just checking Activity.Attachments.Any() will give you a boolean which will tell you if a user uploaded a file or not.

Here is a simple example inside a RootDialog.cs :

using Microsoft.Bot.Builder.Dialogs;
using Microsoft.Bot.Connector;
using System;
using System.Linq;
using System.Net;
using System.Threading.Tasks;

namespace Bot_Application1.Dialogs
{
    [Serializable]
    public class RootDialog : IDialog<object>
    {
        public Task StartAsync(IDialogContext context)
        {
            context.Wait(MessageReceivedAsync);

            return Task.CompletedTask;
        }

        private async Task MessageReceivedAsync(IDialogContext context, IAwaitable<object> result)
        {
            var activity = await result as Activity;

            if (activity.Attachments.Any())
            {
                //do something with the file
                //it looks like this is where you would put your 
                //context.Forward() 
                await context.Forward(new ReceiveAttachmentDialog(), this.ResumeAfterRecieveDialog, context.Activity, CancellationToken.None);

                await context.PostAsync($"you sent a file");
            }
            else
            {
                await context.PostAsync($"No File received");
            }
            context.Wait(MessageReceivedAsync);
        }
    }
}