Building Workflow Driven .NET Applications With Elsa 2 - Part 7

ConfigureJavaScriptEngineWithCustomFunctions1.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using Elsa.Scripting.JavaScript.Events;
using Elsa.Scripting.JavaScript.Messages;
using MediatR;
using Microsoft.AspNetCore.StaticFiles;

namespace DocumentManagement.Workflows.Scripting.JavaScript
{
    /// <summary>
    /// Registers custom JS functions.
    /// </summary>
    public class ConfigureJavaScriptEngineWithCustomFunctions : INotificationHandler<EvaluatingJavaScriptExpression>
    {
        private readonly IContentTypeProvider _contentTypeProvider;

        public ConfigureJavaScriptEngineWithCustomFunctions(IContentTypeProvider contentTypeProvider)
        {
            _contentTypeProvider = contentTypeProvider;
        }

        public Task Handle(EvaluatingJavaScriptExpression notification, CancellationToken cancellationToken)
        {
            var engine = notification.Engine;

            engine.SetValue("contentTypeFromFileName", (Func<string, string>) GetContentType);

            return Task.CompletedTask;
        }

        private string GetContentType(string fileName) => _contentTypeProvider.TryGetContentType(fileName, out var contentType) ? contentType : "application/octet-stream";
    }
}

ConfigureJavaScriptEngineWithCustomFunctions2.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using Elsa.Scripting.JavaScript.Events;
using Elsa.Scripting.JavaScript.Messages;
using MediatR;
using Microsoft.AspNetCore.StaticFiles;

namespace DocumentManagement.Workflows.Scripting.JavaScript
{
    /// <summary>
    /// Registers custom JS functions and type definitions.
    /// </summary>
    public class ConfigureJavaScriptEngineWithCustomFunctions : INotificationHandler<EvaluatingJavaScriptExpression>, INotificationHandler<RenderingTypeScriptDefinitions>
    {
        private readonly IContentTypeProvider _contentTypeProvider;

        public ConfigureJavaScriptEngineWithCustomFunctions(IContentTypeProvider contentTypeProvider)
        {
            _contentTypeProvider = contentTypeProvider;
        }

        public Task Handle(EvaluatingJavaScriptExpression notification, CancellationToken cancellationToken)
        {
            var engine = notification.Engine;

            engine.SetValue("contentTypeFromFileName", (Func<string, string>) GetContentType);

            return Task.CompletedTask;
        }

        public Task Handle(RenderingTypeScriptDefinitions notification, CancellationToken cancellationToken)
        {
            var output = notification.Output;

            output.AppendLine("declare function contentTypeFromFileName(fileName: string): string");

            return Task.CompletedTask;
        }

        private string GetContentType(string fileName) => _contentTypeProvider.TryGetContentType(fileName, out var contentType) ? contentType : "application/octet-stream";
    }
}

CustomTypeDefinitionProvider.cs

using System;
using System.Collections.Generic;
using DocumentManagement.Workflows.Activities;
using Elsa.Scripting.JavaScript.Services;

namespace DocumentManagement.Workflows.Scripting.JavaScript
{
    /// <summary>
    /// Register .NET types for which we want to include with JS intellisense.
    /// </summary>
    public class CustomTypeDefinitionProvider : TypeDefinitionProvider
    {
        public override IEnumerable<Type> CollectTypes(TypeDefinitionContext context)
        {
            yield return typeof(DocumentFile);
        }
    }
}

DisplaySignalReceivedPage1.cs

using System.Threading;
using System.Threading.Tasks;
using Elsa.Activities.Http.Events;
using MediatR;
using Microsoft.AspNetCore.Http;

namespace DocumentManagement.Web.Handlers
{
    /// <summary>
    /// Responds to the Accept or Reject signal when the user clicks either option from the email.
    /// </summary>
    public class DisplaySignalReceivedPage : INotificationHandler<HttpTriggeredSignal>
    {
        private readonly IHttpContextAccessor _httpContextAccessor;

        public DisplaySignalReceivedPage(IHttpContextAccessor httpContextAccessor)
        {
            _httpContextAccessor = httpContextAccessor;
        }

        public Task Handle(HttpTriggeredSignal notification, CancellationToken cancellationToken)
        {
            var affectedWorkflows = notification.AffectedWorkflows;

            // Exit if no workflows were affected.
            if (affectedWorkflows.Count == 0)
                return Task.CompletedTask;

            var signalName = notification.SignalModel.Name;
            var response = _httpContextAccessor.HttpContext!.Response;

            // Redirect to the appropriate page.
            switch (signalName)
            {
                case "Approve":
                    response.Redirect("/leave-request-approved");
                    break;
                case "Reject":
                    response.Redirect("/leave-request-denied");
                    break;
            }

            return Task.CompletedTask;
        }
    }
}

DisplaySignalReceivedPage2.cs

using System.Threading;
using System.Threading.Tasks;
using Elsa.Activities.Http.Events;
using MediatR;
using Microsoft.AspNetCore.Http;

namespace DocumentManagement.Web.Handlers
{
    /// <summary>
    /// Responds to the Accept or Reject signal when the user clicks either option from the email.
    /// </summary>
    public class DisplaySignalReceivedPage : INotificationHandler<HttpTriggeredSignal>
    {
        private readonly IHttpContextAccessor _httpContextAccessor;

        public DisplaySignalReceivedPage(IHttpContextAccessor httpContextAccessor)
        {
            _httpContextAccessor = httpContextAccessor;
        }

        public Task Handle(HttpTriggeredSignal notification, CancellationToken cancellationToken)
        {
            var affectedWorkflows = notification.AffectedWorkflows;

            // Exit if no workflows were affected.
            if (affectedWorkflows.Count == 0)
                return Task.CompletedTask;

            var signalName = notification.SignalModel.Name;
            var response = _httpContextAccessor.HttpContext!.Response;

            // Redirect to the appropriate page.
            switch (signalName)
            {
                case "Approve":
                    response.Redirect("/leave-request-approved");
                    break;
                case "Reject":
                    response.Redirect("/leave-request-denied");
                    break;
                case "Valid":
                    response.Redirect("/identity-confirmed");
                    break;
                case "Fake":
                    response.Redirect("/identity-theft-confirmed");
                    break;
            }

            return Task.CompletedTask;
        }
    }
}

LeaveRequest-SendEmail-Attachments.js

const fileName = input.Document.FileName;
const contentType = contentTypeFromFileName(fileName);
const attachment = new EmailAttachment(input.FileStream, fileName, contentType);

return attachment;

LeaveRequest-SendEmail.liquid

<p>Please review attached leave request.</p>

<a href="{{ "Approve" | signal_url }}">Appove</a> or <a href="{{ "Reject" | signal_url }}">Reject</a>

LeaveRequestApproved.cshtml

@page "/leave-request-approved"
@{
    ViewData["Title"] = "Leave Request Approved";
}

<div>
    <h1 class="display-4">Leave Request Approved</h1>
    <p>We will let the happy employee know. Thank you!</p>
</div>

LeaveRequestDenied.cshtml

@page "/leave-request-denied"
@{
    ViewData["Title"] = "Leave Request Denied";
}

<div>
    <h1 class="display-4">Leave Request Denied</h1>
    <p>We will let the lazy employee know there's no time for that. Thank you!</p>
</div>