PosInformatique.Foundations.Text.Templating.Razor 1.0.0

PosInformatique.Foundations.Text.Templating.Razor

Introduction

This package provides a simple way to generate text from Razor components (views) outside of ASP.NET Core MVC/Blazor pages. It is an implementation of the core PosInformatique.Foundations.Text.Templating library.

You define a Razor component with a Model parameter, and the library renders it to a TextWriter by using a RazorTextTemplate<TModel> implementation. The Razor component can also inject any service registered in the application IServiceCollection.

Install

You can install the package from NuGet:

dotnet add package PosInformatique.Foundations.Text.Templating.Razor

Features

• Render text from Razor components (Blazor-style components)
• Strongly-typed model passed via a Model parameter
• Integrates with dependency injection (IServiceCollection / IServiceProvider)
• Ability to inject any registered service directly in the Razor component with @inject
• Simple registration via AddRazorTextTemplating(IServiceCollection)

Basic usage

1. Register the Razor text templating

You must register the Razor text templating rendering infrastructure in your DI container:

var services = new ServiceCollection();

// Register application services
services.AddLogging();

// Register Razor text templating
services.AddRazorTextTemplating();

// Build the service provider used as context
var serviceProvider = services.BuildServiceProvider();

2. Create a Razor component (view)

Create a Razor component that will be used as a template, for example HelloTemplate.razor:

@using System
@using Microsoft.Extensions.Logging

@inherits ComponentBase

@code {
    // The model automatically injected by RazorTextTemplate<TModel>
    [Parameter]
    public MyEmailModel? Model { get; set; }

    protected override void OnInitialized()
    {
        // You can use Blazor event as usual (OnInitialized, OnParametersSet, etc.)
        this.Model.Now = DateTime.UtcNow;
    }
}

Hello this.Model.UserName !
Today is this.Model.Now:U

Key points:

• The model is received via a Model parameter (it is automatically set by the library).
• You can inject any service registered in IServiceCollection using @inject (or [Inject] attribute in code-behind).

3. Use RazorTextTemplate<TModel>.RenderAsync()

You can now create a RazorTextTemplate<TModel> instance, build a rendering context that exposes an IServiceProvider, and call RenderAsync():

using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using PosInformatique.Foundations.Text.Templating;
using PosInformatique.Foundations.Text.Templating.Razor;

// Example of a simple ITextTemplateRenderContext implementation
public class TextTemplateRenderContext : ITextTemplateRenderContext
{
    public TextTemplateRenderContext(IServiceProvider serviceProvider)
    {
        this.ServiceProvider = serviceProvider;
    }

    public IServiceProvider ServiceProvider { get; }
}

public static class RazorTemplateSample
{
    public static async Task GenerateAsync()
    {
        var services = new ServiceCollection();
        services.AddRazorTextTemplating();

        var serviceProvider = services.BuildServiceProvider();

        // Create the Razor text template that uses the HelloTemplate component
        var template = new RazorTextTemplate<MyEmailModel>(typeof(HelloTemplate));

        // Build the context that provides IServiceProvider
        var context = new TextTemplateRenderContext(serviceProvider);

        using var writer = new StringWriter();

        // Render the template with a string model
        var model = new MyEmailModel { UserName = "John" };
        await template.RenderAsync(model, writer, context, CancellationToken.None);

        var result = writer.ToString();
        Console.WriteLine(result);
    }
}

4. Injecting other services in the Razor view

Any service registered in your IServiceCollection and available through IServiceProvider can be injected in the Razor component.

Example:

@using MyApp.Services
@inherits ComponentBase

@code {
    [Parameter]
    public MyEmailModel? Model { get; set; }

    [Inject]
    public IDateTimeProvider DateTimeProvider { get; set; } = default!

    [Inject]
    public IMyFormatter Formatter { get; set; } = default!
}

Hello @Model?.Name,

Current time: @this.DateTimeProvider.UtcNow
Formatted data: @this.Formatter.Format(Model)

As long as IDateTimeProvider and IMyFormatter are registered in the IServiceCollection, they are available during template rendering.

Links

• NuGet package: Emailing.Templates.Razor
• NuGet package: Text.Templating (core library)
• NuGet package: Text.Templating.Razor
• Source code