DKNet.Svc.Transformation 10.1.17

DKNet.Svc.Transformation

Template-token substitution: fills bracketed tokens ([Name], {Email}, <Amount>, {{Ref}}) in a string from a plain object or a IDictionary<string, string>, with pluggable value formatting. Not an object mapper, and not a template engine — there are no conditionals, loops, or partials.

Features

• ITransformerService — Transform/TransformAsync a template against one or more parameter sources
• Four built-in token styles (square/curly/angle/double-curly brackets), or define your own pair
• Configurable behaviour when a token cannot be resolved (ThrowError, LeaveAsIs, Remove)
• Pluggable IValueFormatter for bool/number/date formatting, invariant-culture by default
• Global parameters shared across every template

Installation

dotnet add package DKNet.Svc.Transformation

Quick Start

using DKNet.Svc.Transformation;
using Microsoft.Extensions.DependencyInjection;

builder.Services.AddTransformerService(); // ITransformerService, transient

public sealed class WelcomeEmailBuilder(ITransformerService transformer)
{
    public Task<string> BuildAsync(User user) =>
        transformer.TransformAsync("Hello [Name], your account [Email] is ready.", user);
}

AddTransformerService(Action<TransformOptions>? optionFactory = null) is the only registration entry point. It builds one TransformOptions, registers it as IOptions<TransformOptions>, and registers ITransformerService → TransformerService as transient. It returns immediately if ITransformerService is already registered, so the first call's options win and a later call's delegate is silently ignored.

Configuration — TransformOptions

Configured in code through the delegate passed to AddTransformerService. There is no IConfiguration binding path for this package.

Built-in definitions, all static readonly on TransformOptions: SquareBrackets ([Token]), CurlyBrackets ({Token}), AngledBrackets (<Token>), DoubleCurlyBrackets ({{Token}}). Define your own with new TokenDefinition(begin, end), which throws ArgumentException for a null or whitespace tag.

ValueFormatter is a public class with virtual members — subclass it to change just the formats:

bool renders as Yes/No; int/long use IntegerFormat; double/decimal/float use NumberFormat; DateTime/DateTimeOffset use DateFormat; anything else falls back to ToString(). All formatting runs against CultureInfo.InvariantCulture.

Public extension points

Documentation

Full feature reference, diagrams, and gotchas: https://github.com/baoduy/DKNet/blob/main/docs/Services/DKNet.Svc.Transformation.md