.NET Coreで記述している.NETコンソールアプリケーションのテンプレートエンジンとしてRazorを使用したいと思います。
私が出会ったスタンドアロンのRazorエンジン(RazorEngine、RazorTemplates)はすべて、完全な.NETを必要とします。 .NET Coreで動作するソリューションを探しています。
最近、 RazorLight というライブラリを作成しました。
ASP.NET MVCパーツのような冗長な依存関係はなく、コンソールアプリケーションで使用できます。現時点では、.NET Core(NetStandard1.6)のみをサポートしていますが、それがまさに必要なものです。
短い例を次に示します。
IRazorLightEngine engine = EngineFactory.CreatePhysical("Path-to-your-views");
// Files and strong models
string resultFromFile = engine.Parse("Test.cshtml", new Model("SomeData"));
// Strings and anonymous models
string stringResult = engine.ParseString("Hello @Model.Name", new { Name = "John" });
Razor(解析およびC#コード生成用)およびRoslyn(C#コードコンパイル用ですが、古いCodeDomも使用できます)のみに依存するサンプルコードを次に示します。
そのコードにはMVCがないため、ビュー、.cshtmlファイル、コントローラー、Razorソースの解析およびコンパイルされたランタイム実行はありません。しかし、まだモデルの概念があります。
追加する必要があるのは、次のnugetパッケージ:Microsoft.AspNetCore.Razor.Language
(v2.1.1)、Microsoft.AspNetCore.Razor.Runtime
(v2.1.1)、およびMicrosoft.CodeAnalysis.CSharp
(v2.8.2)nugetsです。
このC#ソースコードは、NETCore、NETStandard 2、および.NET Frameworkと互換性があります。それをテストするには、.NETフレームワークまたは.NETコアコンソールアプリを作成し、貼り付けて、ナゲットを追加するだけです。
using System;
using System.IO;
using System.Reflection;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Razor.Hosting;
using Microsoft.AspNetCore.Razor.Language;
using Microsoft.AspNetCore.Razor.Language.Extensions;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
namespace RazorTemplate
{
class Program
{
static void Main(string[] args)
{
// points to the local path
var fs = RazorProjectFileSystem.Create(".");
// customize the default engine a little bit
var engine = RazorProjectEngine.Create(RazorConfiguration.Default, fs, (builder) =>
{
InheritsDirective.Register(builder);
builder.SetNamespace("MyNamespace"); // define a namespace for the Template class
});
// get a razor-templated file. My "hello.txt" template file is defined like this:
//
// @inherits RazorTemplate.MyTemplate
// Hello @Model.Name, welcome to Razor World!
//
var item = fs.GetItem("hello.txt");
// parse and generate C# code, outputs it on the console
//var cs = te.GenerateCode(item);
//Console.WriteLine(cs.GeneratedCode);
var codeDocument = engine.Process(item);
var cs = codeDocument.GetCSharpDocument();
// now, use roslyn, parse the C# code
var tree = CSharpSyntaxTree.ParseText(cs.GeneratedCode);
// define the dll
const string dllName = "hello";
var compilation = CSharpCompilation.Create(dllName, new[] { tree },
new[]
{
MetadataReference.CreateFromFile(typeof(object).Assembly.Location), // include corlib
MetadataReference.CreateFromFile(typeof(RazorCompiledItemAttribute).Assembly.Location), // include Microsoft.AspNetCore.Razor.Runtime
MetadataReference.CreateFromFile(Assembly.GetExecutingAssembly().Location), // this file (that contains the MyTemplate base class)
// for some reason on .NET core, I need to add this... this is not needed with .NET framework
MetadataReference.CreateFromFile(Path.Combine(Path.GetDirectoryName(typeof(object).Assembly.Location), "System.Runtime.dll")),
// as found out by @Isantipov, for some other reason on .NET Core for Mac and Linux, we need to add this... this is not needed with .NET framework
MetadataReference.CreateFromFile(Path.Combine(Path.GetDirectoryName(typeof(object).Assembly.Location), "netstandard.dll"))
},
new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary)); // we want a dll
// compile the dll
string path = Path.Combine(Path.GetFullPath("."), dllName + ".dll");
var result = compilation.Emit(path);
if (!result.Success)
{
Console.WriteLine(string.Join(Environment.NewLine, result.Diagnostics));
return;
}
// load the built dll
Console.WriteLine(path);
var asm = Assembly.LoadFile(path);
// the generated type is defined in our custom namespace, as we asked. "Template" is the type name that razor uses by default.
var template = (MyTemplate)Activator.CreateInstance(asm.GetType("MyNamespace.Template"));
// run the code.
// should display "Hello Killroy, welcome to Razor World!"
template.ExecuteAsync().Wait();
}
}
// the model class. this is 100% specific to your context
public class MyModel
{
// this will map to @Model.Name
public string Name => "Killroy";
}
// the sample base template class. It's not mandatory but I think it's much easier.
public abstract class MyTemplate
{
// this will map to @Model (property name)
public MyModel Model => new MyModel();
public void WriteLiteral(string literal)
{
// replace that by a text writer for example
Console.Write(literal);
}
public void Write(object obj)
{
// replace that by a text writer for example
Console.Write(obj);
}
public async virtual Task ExecuteAsync()
{
await Task.Yield(); // whatever, we just need something that compiles...
}
}
}
aspnet/Entropy/samples/Mvc.RenderViewToString に.NET Core 1.0の実用例があります。これは変更されるか、なくなる可能性があるため、ここで自分のアプリケーションで使用しているアプローチを詳しく説明します。
Tl; dr-RazorはMVC以外でも非常にうまく機能します!このアプローチでは、部分ビューやビューへのオブジェクトの挿入など、より複雑なレンダリングシナリオも処理できますが、以下の簡単な例を示します。
コアサービスは次のようになります。
RazorViewToStringRenderer.cs
using System;
using System.IO;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.Razor;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Routing;
namespace RenderRazorToString
{
public class RazorViewToStringRenderer
{
private readonly IRazorViewEngine _viewEngine;
private readonly ITempDataProvider _tempDataProvider;
private readonly IServiceProvider _serviceProvider;
public RazorViewToStringRenderer(
IRazorViewEngine viewEngine,
ITempDataProvider tempDataProvider,
IServiceProvider serviceProvider)
{
_viewEngine = viewEngine;
_tempDataProvider = tempDataProvider;
_serviceProvider = serviceProvider;
}
public async Task<string> RenderViewToString<TModel>(string name, TModel model)
{
var actionContext = GetActionContext();
var viewEngineResult = _viewEngine.FindView(actionContext, name, false);
if (!viewEngineResult.Success)
{
throw new InvalidOperationException(string.Format("Couldn't find view '{0}'", name));
}
var view = viewEngineResult.View;
using (var output = new StringWriter())
{
var viewContext = new ViewContext(
actionContext,
view,
new ViewDataDictionary<TModel>(
metadataProvider: new EmptyModelMetadataProvider(),
modelState: new ModelStateDictionary())
{
Model = model
},
new TempDataDictionary(
actionContext.HttpContext,
_tempDataProvider),
output,
new HtmlHelperOptions());
await view.RenderAsync(viewContext);
return output.ToString();
}
}
private ActionContext GetActionContext()
{
var httpContext = new DefaultHttpContext
{
RequestServices = _serviceProvider
};
return new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
}
}
}
単純なテストコンソールアプリは、サービス(およびいくつかのサポートサービス)を初期化して呼び出すだけです。
Program.cs
using System;
using System.Diagnostics;
using System.IO;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Hosting.Internal;
using Microsoft.AspNetCore.Mvc.Razor;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.FileProviders;
using Microsoft.Extensions.ObjectPool;
using Microsoft.Extensions.PlatformAbstractions;
namespace RenderRazorToString
{
public class Program
{
public static void Main()
{
// Initialize the necessary services
var services = new ServiceCollection();
ConfigureDefaultServices(services);
var provider = services.BuildServiceProvider();
var renderer = provider.GetRequiredService<RazorViewToStringRenderer>();
// Build a model and render a view
var model = new EmailViewModel
{
UserName = "User",
SenderName = "Sender"
};
var emailContent = renderer.RenderViewToString("EmailTemplate", model).GetAwaiter().GetResult();
Console.WriteLine(emailContent);
Console.ReadLine();
}
private static void ConfigureDefaultServices(IServiceCollection services)
{
var applicationEnvironment = PlatformServices.Default.Application;
services.AddSingleton(applicationEnvironment);
var appDirectory = Directory.GetCurrentDirectory();
var environment = new HostingEnvironment
{
WebRootFileProvider = new PhysicalFileProvider(appDirectory),
ApplicationName = "RenderRazorToString"
};
services.AddSingleton<IHostingEnvironment>(environment);
services.Configure<RazorViewEngineOptions>(options =>
{
options.FileProviders.Clear();
options.FileProviders.Add(new PhysicalFileProvider(appDirectory));
});
services.AddSingleton<ObjectPoolProvider, DefaultObjectPoolProvider>();
var diagnosticSource = new DiagnosticListener("Microsoft.AspNetCore");
services.AddSingleton<DiagnosticSource>(diagnosticSource);
services.AddLogging();
services.AddMvc();
services.AddSingleton<RazorViewToStringRenderer>();
}
}
}
これは、ビューモデルクラスがあることを前提としています。
EmailViewModel.cs
namespace RenderRazorToString
{
public class EmailViewModel
{
public string UserName { get; set; }
public string SenderName { get; set; }
}
}
そして、レイアウトファイルとビューファイル:
Views/_Layout.cshtml
<!DOCTYPE html>
<html>
<body>
<div>
@RenderBody()
</div>
<footer>
Thanks,<br />
@Model.SenderName
</footer>
</body>
</html>
Views/EmailTemplate.cshtml
@model RenderRazorToString.EmailViewModel
@{
Layout = "_EmailLayout";
}
Hello @Model.UserName,
<p>
This is a generic email about something.<br />
<br />
</p>
ASP.NET Core 2.0プロジェクトでスコープサービスとして機能するNateの回答を取得するためのクラスを次に示します。
using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.Razor;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Routing;
namespace YourNamespace.Services
{
public class ViewRender : IViewRender
{
private readonly IRazorViewEngine _viewEngine;
private readonly ITempDataProvider _tempDataProvider;
private readonly IServiceProvider _serviceProvider;
public ViewRender(
IRazorViewEngine viewEngine,
ITempDataProvider tempDataProvider,
IServiceProvider serviceProvider)
{
_viewEngine = viewEngine;
_tempDataProvider = tempDataProvider;
_serviceProvider = serviceProvider;
}
public async Task<string> RenderAsync(string name)
{
return await RenderAsync<object>(name, null);
}
public async Task<string> RenderAsync<TModel>(string name, TModel model)
{
var actionContext = GetActionContext();
var viewEngineResult = _viewEngine.FindView(actionContext, name, false);
if (!viewEngineResult.Success)
{
throw new InvalidOperationException(string.Format("Couldn't find view '{0}'", name));
}
var view = viewEngineResult.View;
using (var output = new StringWriter())
{
var viewContext = new ViewContext(
actionContext,
view,
new ViewDataDictionary<TModel>(
metadataProvider: new EmptyModelMetadataProvider(),
modelState: new ModelStateDictionary())
{
Model = model
},
new TempDataDictionary(
actionContext.HttpContext,
_tempDataProvider),
output,
new HtmlHelperOptions());
await view.RenderAsync(viewContext);
return output.ToString();
}
}
private ActionContext GetActionContext()
{
var httpContext = new DefaultHttpContext {RequestServices = _serviceProvider};
return new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
}
}
public interface IViewRender
{
Task<string> RenderAsync(string name);
Task<string> RenderAsync<TModel>(string name, TModel model);
}
}
Startup.csで
public void ConfigureServices(IServiceCollection services)
{
services.AddScoped<IViewRender, ViewRender>();
}
コントローラー内
public class VenuesController : Controller
{
private readonly IViewRender _viewRender;
public VenuesController(IViewRender viewRender)
{
_viewRender = viewRender;
}
public async Task<IActionResult> Edit()
{
string html = await _viewRender.RenderAsync("Emails/VenuePublished", venue.Name);
return Ok();
}
}
かみそりのライトをいじるのに数日費やしましたが、htmlヘルパー(@ Html。*)やurlヘルパーがないなど、いくつかの欠点があります。
Mvcアプリの外部で使用するためにカプセル化されたソリューションを次に示します。 aspnetコアおよびmvcへのパッケージ参照が必要ですが、これらはサービスまたはコンソールアプリケーションに簡単に追加できます。コントローラやWebサーバーは必要ありません。 RenderToStringAsyncは、ビューを文字列にレンダリングするために呼び出すメソッドです。
利点は、.netコアWebプロジェクトと同じ方法でビューを作成できることです。同じ@Htmlおよび他のヘルパー関数とメソッドを使用できます。
独自のカスタムプロバイダーでカミソリビューオプションのセットアップで物理ファイルプロバイダーを置換または追加して、データベースやWebサービス呼び出しなどからビューをロードできます。WindowsおよびLinuxで.net core 2.2でテスト済み。
.csprojファイルの先頭行にこれが必要であることに注意してください。
<Project Sdk="Microsoft.NET.Sdk.Web">
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Dynamic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Hosting.Internal;
using Microsoft.AspNetCore.Mvc.Razor;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.FileProviders;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.ObjectPool;
namespace RazorRendererNamespace
{
/// <summary>
/// Renders razor pages with the absolute minimum setup of MVC, easy to use in console application, does not require any other classes or setup.
/// </summary>
public class RazorRenderer : ILoggerFactory, ILogger
{
private class ViewRenderService : IDisposable, ITempDataProvider, IServiceProvider
{
private static readonly System.Net.IPAddress localIPAddress = System.Net.IPAddress.Parse("127.0.0.1");
private readonly Dictionary<string, object> tempData = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
private readonly IRazorViewEngine _viewEngine;
private readonly ITempDataProvider _tempDataProvider;
private readonly IServiceProvider _serviceProvider;
private readonly IHttpContextAccessor _httpContextAccessor;
public ViewRenderService(IRazorViewEngine viewEngine,
IHttpContextAccessor httpContextAccessor,
ITempDataProvider tempDataProvider,
IServiceProvider serviceProvider)
{
_viewEngine = viewEngine;
_httpContextAccessor = httpContextAccessor;
_tempDataProvider = tempDataProvider ?? this;
_serviceProvider = serviceProvider ?? this;
}
public void Dispose()
{
}
public async Task<string> RenderToStringAsync<TModel>(string viewName, TModel model, ExpandoObject viewBag = null, bool isMainPage = false)
{
HttpContext httpContext;
if (_httpContextAccessor?.HttpContext != null)
{
httpContext = _httpContextAccessor.HttpContext;
}
else
{
DefaultHttpContext defaultContext = new DefaultHttpContext { RequestServices = _serviceProvider };
defaultContext.Connection.RemoteIpAddress = localIPAddress;
httpContext = defaultContext;
}
var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
using (var sw = new StringWriter())
{
var viewResult = _viewEngine.FindView(actionContext, viewName, isMainPage);
if (viewResult.View == null)
{
viewResult = _viewEngine.GetView("~/", viewName, isMainPage);
}
if (viewResult.View == null)
{
return null;
}
var viewDictionary = new ViewDataDictionary(new EmptyModelMetadataProvider(), new ModelStateDictionary())
{
Model = model
};
if (viewBag != null)
{
foreach (KeyValuePair<string, object> kv in (viewBag as IDictionary<string, object>))
{
viewDictionary.Add(kv.Key, kv.Value);
}
}
var viewContext = new ViewContext(
actionContext,
viewResult.View,
viewDictionary,
new TempDataDictionary(actionContext.HttpContext, _tempDataProvider),
sw,
new HtmlHelperOptions()
);
await viewResult.View.RenderAsync(viewContext);
return sw.ToString();
}
}
object IServiceProvider.GetService(Type serviceType)
{
return null;
}
IDictionary<string, object> ITempDataProvider.LoadTempData(HttpContext context)
{
return tempData;
}
void ITempDataProvider.SaveTempData(HttpContext context, IDictionary<string, object> values)
{
}
}
private readonly string rootPath;
private readonly ServiceCollection services;
private readonly ServiceProvider serviceProvider;
private readonly ViewRenderService viewRenderer;
public RazorRenderer(string rootPath)
{
this.rootPath = rootPath;
services = new ServiceCollection();
ConfigureDefaultServices(services);
serviceProvider = services.BuildServiceProvider();
viewRenderer = new ViewRenderService(serviceProvider.GetRequiredService<IRazorViewEngine>(), null, null, serviceProvider);
}
private void ConfigureDefaultServices(IServiceCollection services)
{
var environment = new HostingEnvironment
{
WebRootFileProvider = new PhysicalFileProvider(rootPath),
ApplicationName = typeof(RazorRenderer).Assembly.GetName().Name,
ContentRootPath = rootPath,
WebRootPath = rootPath,
EnvironmentName = "DEVELOPMENT",
ContentRootFileProvider = new PhysicalFileProvider(rootPath)
};
services.AddSingleton<IHostingEnvironment>(environment);
services.Configure<RazorViewEngineOptions>(options =>
{
options.FileProviders.Clear();
options.FileProviders.Add(new PhysicalFileProvider(rootPath));
});
services.AddSingleton<ObjectPoolProvider, DefaultObjectPoolProvider>();
services.AddSingleton<ILoggerFactory>(this);
var diagnosticSource = new DiagnosticListener(environment.ApplicationName);
services.AddSingleton<DiagnosticSource>(diagnosticSource);
services.AddMvc();
}
public void Dispose()
{
}
public Task<string> RenderToStringAsync<TModel>(string viewName, TModel model, ExpandoObject viewBag = null, bool isMainPage = false)
{
return viewRenderer.RenderToStringAsync(viewName, model, viewBag, isMainPage);
}
void ILoggerFactory.AddProvider(ILoggerProvider provider)
{
}
IDisposable ILogger.BeginScope<TState>(TState state)
{
throw new NotImplementedException();
}
ILogger ILoggerFactory.CreateLogger(string categoryName)
{
return this;
}
bool ILogger.IsEnabled(Microsoft.Extensions.Logging.LogLevel logLevel)
{
return false;
}
void ILogger.Log<TState>(Microsoft.Extensions.Logging.LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
{
}
}
}