Handling Dialog Submissions

Dialogs have a specific TaskSubmit event to handle submissions. When a user submits a form inside a dialog, the app is notified via this event, which is then handled to process the submission values, and can either send a response or proceed to more steps in the dialogs (see Multi-step Dialogs).

Return Type Requirement

Methods decorated with [TaskSubmit] must return Task<Microsoft.Teams.Api.TaskModules.Response>. Every code path must return a Response object containing either a MessageTask (to show a message and close the dialog) or a ContinueTask (to show another dialog). Using just Task or void will compile but fail at runtime when the Teams client expects a Response object.

Basic Example

In this example, we show how to handle dialog submissions from an Adaptive Card form:

using System.Text.Json;
using Microsoft.Teams.Api.TaskModules;
using Microsoft.Teams.Apps;
using Microsoft.Teams.Apps.Activities.Invokes;
using Microsoft.Teams.Apps.Annotations;
using Microsoft.Teams.Common.Logging;

//...

[TaskSubmit]
public async Task<Microsoft.Teams.Api.TaskModules.Response> OnTaskSubmit([Context] Tasks.SubmitActivity activity, [Context] IContext.Client client, [Context] ILogger log)
{
    var data = activity.Value?.Data as JsonElement?;
    if (data == null)
    {
        log.Info("[TASK_SUBMIT] No data found in the activity value");
        return new Microsoft.Teams.Api.TaskModules.Response(
            new Microsoft.Teams.Api.TaskModules.MessageTask("No data found in the activity value"));
    }

    var submissionType = data.Value.TryGetProperty("submissiondialogtype", out var submissionTypeObj) && submissionTypeObj.ValueKind == JsonValueKind.String
        ? submissionTypeObj.ToString()
        : null;


    string? GetFormValue(string key)
    {
        if (data.Value.TryGetProperty(key, out var val))
        {
            if (val is JsonElement element)
                return element.GetString();
            return val.ToString();
        }
        return null;
    }

    switch (submissionType)
    {
        case "simple_form":
            var name = GetFormValue("name") ?? "Unknown";
            await client.Send($"Hi {name}, thanks for submitting the form!");
            return new Microsoft.Teams.Api.TaskModules.Response(
                new Microsoft.Teams.Api.TaskModules.MessageTask("Form was submitted"));
        // More examples below
        default:
            return new Microsoft.Teams.Api.TaskModules.Response(
                new Microsoft.Teams.Api.TaskModules.MessageTask("Unknown submission type"));
    }
}

Similarly, handling dialog submissions from rendered webpages is also possible:

// Add this case to the switch statement in OnTaskSubmit method
case "webpage_dialog":
    var webName = GetFormValue("name") ?? "Unknown";
    var email = GetFormValue("email") ?? "No email";
    await client.Send($"Hi {webName}, thanks for submitting the form! We got that your email is {email}");
    return new Microsoft.Teams.Api.TaskModules.Response(
        new Microsoft.Teams.Api.TaskModules.MessageTask("Form submitted successfully"));

Complete TaskSubmit Handler Example

Here's the complete example showing how to handle multiple submission types:

using System.Text.Json;
using Microsoft.Teams.Api.TaskModules;
using Microsoft.Teams.Apps;
using Microsoft.Teams.Apps.Activities.Invokes;
using Microsoft.Teams.Apps.Annotations;
using Microsoft.Teams.Common.Logging;

//...

[TaskSubmit]
public async Task<Microsoft.Teams.Api.TaskModules.Response> OnTaskSubmit([Context] Tasks.SubmitActivity activity, [Context] IContext.Client client, [Context] ILogger log)
{
    var data = activity.Value?.Data as JsonElement?;
    if (data == null)
    {
        log.Info("[TASK_SUBMIT] No data found in the activity value");
        return new Microsoft.Teams.Api.TaskModules.Response(
            new Microsoft.Teams.Api.TaskModules.MessageTask("No data found in the activity value"));
    }

    var submissionType = data.Value.TryGetProperty("submissiondialogtype", out var submissionTypeObj) && submissionTypeObj.ValueKind == JsonValueKind.String
        ? submissionTypeObj.ToString()
        : null;

    string? GetFormValue(string key)
    {
        if (data.Value.TryGetProperty(key, out var val))
        {
            if (val is JsonElement element)
                return element.GetString();
            return val.ToString();
        }
        return null;
    }

    switch (submissionType)
    {
        case "simple_form":
            var name = GetFormValue("name") ?? "Unknown";
            await client.Send($"Hi {name}, thanks for submitting the form!");
            return new Microsoft.Teams.Api.TaskModules.Response(
                new Microsoft.Teams.Api.TaskModules.MessageTask("Form was submitted"));

        case "webpage_dialog":
            var webName = GetFormValue("name") ?? "Unknown";
            var email = GetFormValue("email") ?? "No email";
            await client.Send($"Hi {webName}, thanks for submitting the form! We got that your email is {email}");
            return new Microsoft.Teams.Api.TaskModules.Response(
                new Microsoft.Teams.Api.TaskModules.MessageTask("Form submitted successfully"));

        default:
            return new Microsoft.Teams.Api.TaskModules.Response(
                new Microsoft.Teams.Api.TaskModules.MessageTask("Unknown submission type"));
    }
}