NickSoftware.Switchboard.SourceGenerators 0.1.0-preview.52

Switchboard Source Generators

Roslyn source generators for the Switchboard Amazon Connect framework. Automatically generates FlowBuilder extension methods from attribute-decorated classes.

⚠️ PREVIEW RELEASE: Part of the Switchboard preview release. APIs may change.

Overview

This package provides Roslyn source generators that enable attribute-based flow definitions. Define your custom flow actions using attributes, and the generators create strongly-typed FlowBuilder extension methods automatically.

Features

• Zero Runtime Overhead - Code generated at compile time
• Full IntelliSense - Generated methods appear in IDE autocomplete
• Type-Safe Parameters - Strong typing for all action parameters
• Custom Transitions - Define custom branching logic

Installation

dotnet add package NickSoftware.Switchboard.SourceGenerators --prerelease

This package is typically installed alongside the main Switchboard package:

dotnet add package NickSoftware.Switchboard --prerelease
dotnet add package NickSoftware.Switchboard.SourceGenerators --prerelease

Usage

Define a Custom Flow Action

using Switchboard.SourceGenerators.Attributes;

[FlowAction("VerifyCustomer", Description = "Verifies customer identity")]
public class VerifyCustomerAction
{
    [Parameter("AccountNumber", Required = true)]
    public string AccountNumber { get; set; } = "";

    [Parameter("VerificationType")]
    public string VerificationType { get; set; } = "PIN";

    [Transition("Verified")]
    public string OnVerified { get; set; } = "";

    [Transition("Failed")]
    public string OnFailed { get; set; } = "";

    [Transition("Error")]
    public string OnError { get; set; } = "";
}

Use the Generated Extension Method

var flow = new FlowBuilder()
    .SetName("CustomerVerificationFlow")
    .PlayPrompt("Please enter your account number")
    .VerifyCustomer(action =>
    {
        action.AccountNumber = "$.StoredCustomerInput";
        action.VerificationType = "PIN";
    })
        .OnVerified(b => b.TransferToQueue("Support"))
        .OnFailed(b => b.PlayPrompt("Verification failed").Disconnect())
        .OnError(b => b.PlayPrompt("An error occurred").Disconnect())
    .Build();

Attributes

[FlowAction]

Marks a class as a flow action definition.

[FlowAction("ActionName", Description = "Optional description")]
public class MyAction { }

[Parameter]

Defines an action parameter.

[Parameter("ParameterName", Required = true, DefaultValue = "default")]
public string MyParameter { get; set; }

[Transition]

Defines a transition/branch from the action.

[Transition("TransitionName")]
public string OnTransition { get; set; }

Generated Code

The source generator creates extension methods like:

// Generated code
public static IVerifyCustomerBuilder VerifyCustomer(
    this IFlowBuilder builder,
    Action<VerifyCustomerAction>? configure = null)
{
    // Implementation generated automatically
}

public interface IVerifyCustomerBuilder : IFlowBuilder
{
    IFlowBuilder OnVerified(Action<IFlowBuilder> configure);
    IFlowBuilder OnFailed(Action<IFlowBuilder> configure);
    IFlowBuilder OnError(Action<IFlowBuilder> configure);
}

Viewing Generated Code

In Visual Studio, you can view generated code under:

• Dependencies → Analyzers → NickSoftware.Switchboard.SourceGenerators

Or enable source file output in your project:

<PropertyGroup>
    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
    <CompilerGeneratedFilesOutputPath>Generated</CompilerGeneratedFilesOutputPath>
</PropertyGroup>

Requirements

• .NET Standard 2.0 compatible
• Works with .NET 6.0+ projects

Related Packages

• NickSoftware.Switchboard - Core framework
• NickSoftware.Switchboard.Analyzers - Compile-time validation

Documentation

• 📖 Full Documentation
• 📖 Source Generators Guide
• 🐛 Report Issues

Part of the Switchboard framework for Amazon Connect