我有一个动态生成 Javascript 的网站。生成的代码描述了类型元数据和一些服务器端常量，以便客户端可以轻松地使用服务器的服务——因此它是非常可缓存的。
生成的 Javascript 由 ASP.NET MVC 控制器提供服务；所以它有一个 Uri；说~/MyGeneratedJs。
我想将此 Javascript 包含在与其他静态 Javascript 文件（例如 jQuery 等）一起的 Javascript 包中：所以就像静态文件一样，我希望它在调试模式下单独引用，并以缩小形式与其他文件捆绑在非调试模式。
如何在捆绑包中包含动态生成的 Javascript？
有了VirtualPathProviders这个现在是可能的。将动态内容集成到捆绑过程中需要以下步骤：
编写请求/构建所需内容的逻辑。直接从 Controller 生成内容需要一些工作：
public static class ControllerActionHelper
{
public static string RenderControllerActionToString(string virtualPath)
{
HttpContext httpContext = CreateHttpContext(virtualPath);
HttpContextWrapper httpContextWrapper = new HttpContextWrapper(httpContext);
RequestContext httpResponse = new RequestContext()
{
HttpContext = httpContextWrapper,
RouteData = RouteTable.Routes.GetRouteData(httpContextWrapper)
};
// Set HttpContext.Current if RenderActionToString is called outside of a request
if (HttpContext.Current == null)
{
HttpContext.Current = httpContext;
}
IControllerFactory controllerFactory = ControllerBuilder.Current.GetControllerFactory();
IController controller = controllerFactory.CreateController(httpResponse,
httpResponse.RouteData.GetRequiredString("controller"));
controller.Execute(httpResponse);
return httpResponse.HttpContext.Response.Output.ToString();
}
private static HttpContext CreateHttpContext(string virtualPath)
{
HttpRequest httpRequest = new HttpRequest(string.Empty, ToDummyAbsoluteUrl(virtualPath), string.Empty);
HttpResponse httpResponse = new HttpResponse(new StringWriter());
return new HttpContext(httpRequest, httpResponse);
}
private static string ToDummyAbsoluteUrl(string virtualPath)
{
return string.Format("http://dummy.net{0}", VirtualPathUtility.ToAbsolute(virtualPath));
}
}
实现一个虚拟路径提供者，它包装现有的路径并拦截所有应该传递动态内容的虚拟路径。
public class ControllerActionVirtualPathProvider : VirtualPathProvider
{
public ControllerActionVirtualPathProvider(VirtualPathProvider virtualPathProvider)
{
// Wrap an existing virtual path provider
VirtualPathProvider = virtualPathProvider;
}
protected VirtualPathProvider VirtualPathProvider { get; set; }
public override string CombineVirtualPaths(string basePath, string relativePath)
{
return VirtualPathProvider.CombineVirtualPaths(basePath, relativePath);
}
public override bool DirectoryExists(string virtualDir)
{
return VirtualPathProvider.DirectoryExists(virtualDir);
}
public override bool FileExists(string virtualPath)
{
if (ControllerActionHelper.IsControllerActionRoute(virtualPath))
{
return true;
}
return VirtualPathProvider.FileExists(virtualPath);
}
public override CacheDependency GetCacheDependency(string virtualPath, IEnumerable virtualPathDependencies,
DateTime utcStart)
{
AggregateCacheDependency aggregateCacheDependency = new AggregateCacheDependency();
List<string> virtualPathDependenciesCopy = virtualPathDependencies.Cast<string>().ToList();
// Create CacheDependencies for our virtual Controller Action paths
foreach (string virtualPathDependency in virtualPathDependenciesCopy.ToList())
{
if (ControllerActionHelper.IsControllerActionRoute(virtualPathDependency))
{
aggregateCacheDependency.Add(new ControllerActionCacheDependency(virtualPathDependency));
virtualPathDependenciesCopy.Remove(virtualPathDependency);
}
}
// Aggregate them with the base cache dependency for virtual file paths
aggregateCacheDependency.Add(VirtualPathProvider.GetCacheDependency(virtualPath, virtualPathDependenciesCopy,
utcStart));
return aggregateCacheDependency;
}
public override string GetCacheKey(string virtualPath)
{
return VirtualPathProvider.GetCacheKey(virtualPath);
}
public override VirtualDirectory GetDirectory(string virtualDir)
{
return VirtualPathProvider.GetDirectory(virtualDir);
}
public override VirtualFile GetFile(string virtualPath)
{
if (ControllerActionHelper.IsControllerActionRoute(virtualPath))
{
return new ControllerActionVirtualFile(virtualPath,
new MemoryStream(Encoding.Default.GetBytes(ControllerActionHelper.RenderControllerActionToString(virtualPath))));
}
return VirtualPathProvider.GetFile(virtualPath);
}
public override string GetFileHash(string virtualPath, IEnumerable virtualPathDependencies)
{
return VirtualPathProvider.GetFileHash(virtualPath, virtualPathDependencies);
}
public override object InitializeLifetimeService()
{
return VirtualPathProvider.InitializeLifetimeService();
}
}
public class ControllerActionVirtualFile : VirtualFile
{
public CustomVirtualFile (string virtualPath, Stream stream)
: base(virtualPath)
{
Stream = stream;
}
public Stream Stream { get; private set; }
public override Stream Open()
{
return Stream;
}
}
如果需要，还必须实现 CacheDependency：
public class ControllerActionCacheDependency : CacheDependency
{
public ControllerActionCacheDependency(string virtualPath, int actualizationTime = 10000)
{
VirtualPath = virtualPath;
LastContent = GetContentFromControllerAction();
Timer = new Timer(CheckDependencyCallback, this, actualizationTime, actualizationTime);
}
private string LastContent { get; set; }
private Timer Timer { get; set; }
private string VirtualPath { get; set; }
protected override void DependencyDispose()
{
if (Timer != null)
{
Timer.Dispose();
}
base.DependencyDispose();
}
private void CheckDependencyCallback(object sender)
{
if (Monitor.TryEnter(Timer))
{
try
{
string contentFromAction = GetContentFromControllerAction();
if (contentFromAction != LastContent)
{
LastContent = contentFromAction;
NotifyDependencyChanged(sender, EventArgs.Empty);
}
}
finally
{
Monitor.Exit(Timer);
}
}
}
private string GetContentFromControllerAction()
{
return ControllerActionHelper.RenderControllerActionToString(VirtualPath);
}
}
注册您的虚拟路径提供程序：
public static void RegisterBundles(BundleCollection bundles)
{
// Set the virtual path provider
BundleTable.VirtualPathProvider = new ControllerActionVirtualPathProvider(BundleTable.VirtualPathProvider);
bundles.Add(new Bundle("~/bundle")
.Include("~/Content/static.js")
.Include("~/JavaScript/Route1")
.Include("~/JavaScript/Route2"));
}
可选：将 Intellisense 支持添加到您的视图中。在您的视图中使用<script>标签并让它们被自定义 ViewResult 删除：
public class DynamicContentViewResult : ViewResult
{
public DynamicContentViewResult()
{
StripTags = false;
}
public string ContentType { get; set; }
public bool StripTags { get; set; }
public string TagName { get; set; }
public override void ExecuteResult(ControllerContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
if (string.IsNullOrEmpty(ViewName))
{
ViewName = context.RouteData.GetRequiredString("action");
}
ViewEngineResult result = null;
if (View == null)
{
result = FindView(context);
View = result.View;
}
string viewResult;
using (StringWriter viewContentWriter = new StringWriter())
{
ViewContext viewContext = new ViewContext(context, View, ViewData, TempData, viewContentWriter);
View.Render(viewContext, viewContentWriter);
if (result != null)
{
result.ViewEngine.ReleaseView(context, View);
}
viewResult = viewContentWriter.ToString();
// Strip Tags
if (StripTags)
{
string regex = string.Format("<{0}[^>]*>(.*?)</{0}>", TagName);
Match res = Regex.Match(viewResult, regex,
RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | RegexOptions.Multiline | RegexOptions.Singleline);
if (res.Success && res.Groups.Count > 1)
{
viewResult = res.Groups[1].Value;
}
else
{
throw new InvalidProgramException(
string.Format("Dynamic content produced by View '{0}' expected to be wrapped in '{1}' tag.", ViewName, TagName));
}
}
}
context.HttpContext.Response.ContentType = ContentType;
context.HttpContext.Response.Output.Write(viewResult);
}
}
使用扩展方法或向控制器添加辅助函数：
public static DynamicContentViewResult JavaScriptView(this Controller controller, string viewName, string masterName, object model)
{
if (model != null)
{
controller.ViewData.Model = model;
}
return new DynamicContentViewResult
{
ViewName = viewName,
MasterName = masterName,
ViewData = controller.ViewData,
TempData = controller.TempData,
ViewEngineCollection = controller.ViewEngineCollection,
ContentType = "text/javascript",
TagName = "script",
StripTags = true
};
}
其他类型的动态内容的步骤与此类似。例如，请参阅捆绑和缩小以及嵌入式资源。
如果您想尝试一下，我在GitHub 上添加了一个概念证明存储库。
Darin 是对的，目前捆绑仅适用于静态文件。但是，如果您可以添加具有最新内容的占位符文件，则捆绑会设置文件更改通知，该通知将在占位符文件更改时自动检测。
此外，我们很快将转向使用 VirtualPathProviders，这可能是一种提供动态生成内容的方式。
更新：支持 VPP 的 1.1-alpha1 版本现已发布
这是不可能的。捆绑包仅适用于静态文件。