Azure Bot Service Succinctly^®
by Ed Freitas

CHAPTER 6

Bot Code Structure

Overview

Composer does a lot for us. It acts as an abstraction layer that hides all the underlying code required to create and execute a bot.

Next, we will explore the bot project structure that Composer has bootstrapped and created for us.

Locating the project

If you have Composer running, close and reopen it to locate the folder where Composer has created the bot code. When Composer opens, you will see the name of your bot project and the location on the disk where the project resides.

Composer – Welcome Screen – Location of the Bot Project

Figure 6-a: Composer – Welcome Screen – Location of the Bot Project

Let's navigate to the project's folder (Location) and look at what Composer has created.

Project folder structure

Within the bot project folder, we can find a Visual Studio solution file called ZipcodeBot.sln. We can open it with the latest version of Visual Studio (in my case, the 2019 Community Edition).

Bot Folder Structure and Content

Figure 6-b: Bot Folder Structure and Content

Double-click the ZipcodeBot.sln file to open it. Once it is open, go to Solution Explorer to look at the project structure and files.

Bot Project Structure (Visual Studio)

Figure 6-c: Bot Project Structure (Visual Studio)

As we can see, the ZipcodeBot project contains many folders, each with many files. If we had to create this project structure manually, this would be a significant task; however, Composer took care of this without us noticing.

We won't go through all the details or look at every folder and file. Let's just look at the most critical folders and files.

Bot Project Structure – Most Important Folders and Files

Figure 6-d: Bot Project Structure – Most Important Folders and Files

One of the critical elements of the bot is the controller. The controller—in this case, BotController.cs—is the core engine for processing bot requests to the appropriate route. Let's look at this file.

Code Listing 6-a: BotController.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

using Microsoft.AspNetCore.Mvc;

using Microsoft.Bot.Builder;

using Microsoft.Bot.Builder.Dialogs.Adaptive.Runtime.Settings;

using Microsoft.Bot.Builder.Integration.AspNet.Core;

using Microsoft.Extensions.Configuration;

using Microsoft.Extensions.Logging;

namespace ZipcodeBot.Controllers

{

[ApiController]

public class BotController : ControllerBase

{

private readonly Dictionary<string, IBotFrameworkHttpAdapter>

_adapters = new Dictionary<string, IBotFrameworkHttpAdapter>();

private readonly IBot _bot;

private readonly ILogger<BotController> _logger;

public BotController(

IConfiguration configuration,

IEnumerable<IBotFrameworkHttpAdapter> adapters,

IBot bot,

ILogger<BotController> logger)

{

_bot = bot ?? throw new ArgumentNullException(nameof(bot));

_logger = logger;

var adapterSettings = configuration.GetSection(

AdapterSettings.AdapterSettingsKey).

Get<List<AdapterSettings>>() ??

new List<AdapterSettings>();

adapterSettings.Add(AdapterSettings.CoreBotAdapterSettings);

foreach (var adapter in adapters ??

throw new ArgumentNullException(nameof(adapters)))

{

var settings = adapterSettings.FirstOrDefault(

s => s.Enabled && s.Type == adapter.GetType().FullName);

if (settings != null)

{

_adapters.Add(settings.Route, adapter);

}

[HttpPost]

[HttpGet]

[Route("api/{route}")]

public async Task PostAsync(string route)

{

if (string.IsNullOrEmpty(route))

{

_logger.LogError($"PostAsync: No route provided.");

throw new ArgumentNullException(nameof(route));

}

if (_adapters.TryGetValue(route,

out IBotFrameworkHttpAdapter adapter))

{

if (_logger.IsEnabled(LogLevel.Debug))

{

_logger.LogInformation($"PostAsync: routed '{route}'

to {adapter.GetType().Name}");

}

// Delegating the processing of the HTTP POST to the

// appropriate adapter.

// The adapter will invoke the bot.

await adapter.ProcessAsync(Request,

Response, _bot).ConfigureAwait(false);

}

else

{

_logger.LogError($"PostAsync: No adapter

registered and enabled for route {route}.");

throw new KeyNotFoundException($"No adapter registered

and enabled for route {route}.");

}

Without delving into specific details, the BotController.cs code has two main functionalities. The first is to initialize BotFrameworkHttpAdapter adapters—this occurs within the BotController constructor.

The second functionality is to route incoming requests, which the Postasync method does, by delegating the HTTP request processing to the appropriate adapter.

ZipcodeBot dialog

In Solution Explorer, scroll down, and there you'll find the ZipcodeBot.dialog file, which contains the bot's main logic and rules.

The Project Root Files

Figure 6-e: The Project Root Files

Behind the scenes, the ZipcodeBot.dialog file loads when the bot executes, and this file contains all the main settings that the bot uses to establish the conversation with the user. Let's inspect the contents of this file.

Code Listing 6-b: ZipcodeBot.dialog

{

"$kind": "Microsoft.AdaptiveDialog",

"$designer": {

"name": "ZipcodeBot",

"description": "",

"id": "A79tBe"

"autoEndDialog": true,

"defaultResultProperty": "dialog.result",

"triggers": [

{

"$kind": "Microsoft.OnConversationUpdateActivity",

"$designer": {

"id": "376720"

"actions": [

{

"$kind": "Microsoft.Foreach",

"$designer": {

"id": "518944",

"name": "Loop: for each item"

"itemsProperty": "turn.Activity.membersAdded",

"actions": [

{

"$kind": "Microsoft.IfCondition",

"$designer": {

"id": "641773",

"name": "Branch: if/else"

"condition": "string(dialog.foreach.value.id) !=

string(turn.Activity.Recipient.id)",

"actions": [

{

"$kind": "Microsoft.SendActivity",

"$designer": {

"id": "859266",

"name": "Send a response"

"activity": "${SendActivity_Greeting()}"

}

]

}

]

}

]

{

"$kind": "Microsoft.OnUnknownIntent",

"$designer": {

"id": "mb2n1u"

"actions": [

{

"$kind": "Microsoft.SendActivity",

"$designer": {

"id": "kMjqz1"

"activity": "${SendActivity_DidNotUnderstand()}"

}

]

{

"$kind": "Microsoft.OnIntent",

"$designer": {

"id": "d5ER8p",

"name": "zip"

"intent": "zip",

"actions": [

{

"$kind": "Microsoft.BeginDialog",

"$designer": {

"id": "uvw6RC"

"activityProcessed": true,

"dialog": "get_zip"

}

]

{

"$kind": "Microsoft.OnIntent",

"$designer": {

"id": "RkkXZi",

"name": "cancel"

"intent": "cancel",

"actions": [

{

"$kind": "Microsoft.BeginDialog",

"$designer": {

"id": "KM4gcW"

"activityProcessed": true,

"dialog": "CancelDialog"

}

]

}

"generator": "ZipcodeBot.lg",

"id": "ZipcodeBot",

"recognizer": {

"$kind": "Microsoft.RegexRecognizer",

"intents": [

{

"intent": "zip",

"pattern": "zip"

{

"intent": "cancel",

"pattern": "stop|quit|cancel"

}

]

}

Essentially, we can see that most of the dialog details we created using Composer are here. Notice that in one of the actions, there's a reference to the get_zip dialog. There are references to the Branch: if/else and also the cancel dialog.

The get_zip dialog

Going back to Solution Explorer, double-click the get_zip file to open and inspect it.

Code Listing 6-c: get_zip.dialog

{

"$kind": "Microsoft.AdaptiveDialog",

"$designer": {

"id": "dBaQjz",

"name": "get_zip",

"comment": "Get the zip code"

"autoEndDialog": true,

"defaultResultProperty": "dialog.result",

"triggers": [

{

"$kind": "Microsoft.OnBeginDialog",

"$designer": {

"name": "BeginDialog",

"description": "",

"id": "pCF5nd"

"actions": [

{

"$kind": "Microsoft.SendActivity",

"$designer": {

"id": "J7llQd"

"activity": "${SendActivity_J7llQd()}"

{

"$kind": "Microsoft.TextInput",

"$designer": {

"id": "qJM9qX"

"disabled": false,

"maxTurnCount": 3,

"alwaysPrompt": false,

"allowInterruptions": true,

"prompt": "${TextInput_Prompt_qJM9qX()}",

"unrecognizedPrompt":

"${TextInput_UnrecognizedPrompt_qJM9qX()}",

"property": "user.zip",

"outputFormat": "=trim(this.value)",

"validations": [

"=length(this.value) == 5"

"invalidPrompt": "${TextInput_InvalidPrompt_qJM9qX()}",

"defaultValue": "33165"

{

"$kind": "Microsoft.HttpRequest",

"$designer": {

"id": "itxd2e"

"method": "GET",

"url": "https://app.zipcodebase.com/api/v1/search?

apikey=03b1edc0-2883-11ec-8073-777a767aae15

&codes=${user.zip}&country=US",

"headers": {},

"resultProperty": "dialog.api_response",

"responseType": "json"

{

"$kind": "Microsoft.IfCondition",

"$designer": {

"id": "kOFBrL"

"condition": "=dialog.api_response.statusCode == 200",

"actions": [

{

"$kind": "Microsoft.SetProperties",

"$designer": {

"id": "KhWRrn"

"assignments": [

{

"property": "dialog.postal_code",