使用自定义RazorViewEngine和RazorGenerator预编译视图_Viewengine_Overriding_Razorgenerator

使用自定义RazorViewEngine和RazorGenerator预编译视图

使用自定义RazorViewEngine和RazorGenerator预编译视图,viewengine,overriding,razorgenerator,Viewengine,Overriding,Razorgenerator,我正在尝试使用自定义（派生）RazorViewEngine和使用RazorGenerator的预编译视图一些背景：我们有一个用于多个客户端实现的基础产品。这样我们就有了一组核心的基本视图。大多数视图在大多数时间都有效。现在，我们将复制每个新解决方案的现有视图，并根据需要进行修改。最终，客户端之间95%的视图相同，5%的视图更改我要做的是获取一组基本视图，将它们编译成一个DLL，并跨客户端重用它。到目前为止，我已经使用RazorGenerator很好地工作了现在，下一步是允许自定义（覆盖）

我正在尝试使用自定义（派生）RazorViewEngine和使用RazorGenerator的预编译视图

一些背景：

我们有一个用于多个客户端实现的基础产品。这样我们就有了一组核心的基本视图。大多数视图在大多数时间都有效。现在，我们将复制每个新解决方案的现有视图，并根据需要进行修改。最终，客户端之间95%的视图相同，5%的视图更改

我要做的是获取一组基本视图，将它们编译成一个DLL，并跨客户端重用它。到目前为止，我已经使用RazorGenerator很好地工作了

现在，下一步是允许自定义（覆盖）视图。不过有一个警告。我们的应用程序有两种用户所处的“模式”。他们所处的模式可能需要不同的视图

我已经从RazorGeneratorView创建了一个派生类。此视图主要从Autofac解析的UserProfile对象检查“OrderingMode”。基于模式-替换路径定位器以获得视图分辨率

其想法是，单个客户端应用程序将尝试首先在传统视图文件夹中解析视图。只有我正在添加视图/{OrderingMode}/{Controller}/{View}.cshtml的子目录

如果找不到该视图，那么它将在已编译的库（核心视图）中查找

这使我可以根据客户机的需要覆盖各个视图/部分

    public PosViewEngine() : base()
    {
        //{0} = View Name
        //{1} = ControllerName
        //{2} = Area Name
        AreaViewLocationFormats = new[]
        {
            //First look in the hosting application area folder / Views / ordering type
            //Areas/{AreaName}/{OrderType}/{ControllerName}/{ViewName}.cshtml
            "Areas/{2}/Views/%1/{1}/{0}.cshtml",

            //Next look in the hosting application area folder / Views / ordering type / Shared
            //Areas/{AreaName}/{OrderType}/{ControllerName}/{ViewName}.cshtml
            "Areas/{2}/Views/%1/Shared/(0}.cshtml",

            //Finally look in the IMS.POS.Web.Views.Core assembly
            "Areas/{2}/Views/{1}/{0}.cshtml"
        };

        //Same format logic
        AreaMasterLocationFormats = AreaViewLocationFormats;

        AreaPartialViewLocationFormats = new[]
        {
             //First look in the hosting application area folder / Views / ordering type
            //Areas/{AreaName}/{OrderType}/{ControllerName}/Partials/{PartialViewName}.cshtml
            "Areas/{2}/Views/%1/{1}/Paritals/{0}.cshtml",

            //Next look in the hosting application area folder / Views / ordering type / Shared
            //Areas/{AreaName}/{OrderType}/{ControllerName}/{ViewName}.cshtml
            "Areas/{2}/Views/%1/Shared/(0}.cshtml",

            //Finally look in the IMS.POS.Web.Views.Core
            "Areas/{2}/Views/{1}/{0}.cshtml"
        };

        ViewLocationFormats = new[]
        {
            "Views/%1/{1}/{0}.cshtml",
            "Views/%1/Shared/{0}.cshtml",
            "Views/{1}/{0}.cshtml",
            "Views/Shared/{0}.cshtml"
        };

        MasterLocationFormats = ViewLocationFormats;

        PartialViewLocationFormats = new[]
        {
            "Views/%1/{1}/Partials/{0}.cshtml",
            "Views/%1/Shared/{0}.cshtml",
            "Views/{1}/Partials/{0}.cshtml",
            "Views/Shared/{0}.cshtml"
        };




    }

    protected override IView CreatePartialView(ControllerContext controllerContext, string partialPath)
    {
        return base.CreatePartialView(controllerContext, partialPath.ReplaceOrderType(CurrentOrderingMode()));
    }

    protected override IView CreateView(ControllerContext controllerContext, string viewPath, string masterPath)
    {
        OrderType orderType = CurrentOrderingMode();
        return base.CreateView(controllerContext, viewPath.ReplaceOrderType(orderType), masterPath.ReplaceOrderType(orderType));
    }

    protected override bool FileExists(ControllerContext controllerContext, string virtualPath)
    {
        return base.FileExists(controllerContext, virtualPath.Replace("%1/",string.Empty));
    }


    private OrderType CurrentOrderingMode()
    {
        OrderType result;
        _profileService = DependencyResolver.Current.GetService<IUserProfileService>();

        if (_profileService == null || _profileService.OrderingType == 0)
        {
            IApplicationSettingService settingService =
                DependencyResolver.Current.GetService<IApplicationSettingService>();

            result =
                settingService.GetApplicationSetting(ApplicationSettings.DefaultOrderingMode)
                    .ToEnumTypeOf<OrderType>();
        }
        else
        {
            result = _profileService.OrderingType;
        }

        return result;
    } 



}

问题是：

这段代码是最后执行的（在我注册PosViewEngine之后），它将引擎插入到第一个位置（这意味着这是在提供响应时首先得到解析的引擎）。这最终找到了一个视图——它是核心视图

如果我在启动时更改代码，先注册自定义视图引擎，然后注册RazorGenerator引擎

 public static void Start()
{
    var engine = new PrecompiledMvcEngine(typeof(RazorGeneratorMvcStart).Assembly)
    {
        UsePhysicalViewsIfNewer = HttpContext.Current.Request.IsLocal
    };

    ViewEngines.Engines.Clear();
    ViewEngines.Engines.Insert(0, new PosViewEngine());
    ViewEngines.Engines.Insert(1, engine);

    // StartPage lookups are done by WebPages.
    VirtualPathFactoryManager.RegisterVirtualPathFactory(engine);
}

最后，FileExists（ControllerContext ControllerContext，string virtualPath）方法出现异常-“此处不允许相对虚拟路径'Views/Account/LogOn.cshtml'

这显然与物理路径和虚拟路径混合在一起有关

看起来好像有人试图做同样的事情，但我没有看到答案

对于任何想尝试这种方法的人，我将发布答案。基本上，您需要实现一个自定义视图引擎，该引擎派生自RazorGenerator程序集中的预编译MVCEngine

public class PosPrecompileEngine : PrecompiledMvcEngine
{
    private IUserProfileService _profileService;



    public PosPrecompileEngine(Assembly assembly) : base(assembly)
    {
        LocatorConfig();
    }

    public PosPrecompileEngine(Assembly assembly, string baseVirtualPath) : base(assembly, baseVirtualPath)
    {
        LocatorConfig();
    }

    public PosPrecompileEngine(Assembly assembly, string baseVirtualPath, IViewPageActivator viewPageActivator) : base(assembly, baseVirtualPath, viewPageActivator)
    {
        LocatorConfig();
    }

    protected override IView CreatePartialView(ControllerContext controllerContext, string partialPath)
    {
        return base.CreatePartialView(controllerContext, partialPath.ReplaceOrderType(CurrentOrderingMode()));
    }

    protected override IView CreateView(ControllerContext controllerContext, string viewPath, string masterPath)
    {
        OrderType orderType = CurrentOrderingMode();
        return base.CreateView(controllerContext, viewPath.ReplaceOrderType(orderType), masterPath.ReplaceOrderType(orderType));
    }

    protected override bool FileExists(ControllerContext controllerContext, string virtualPath)
    {
        return base.FileExists(controllerContext, virtualPath.ReplaceOrderType(CurrentOrderingMode()));
    }
}

在这个类中，我覆盖定位器路径。因为我在web应用程序的另一个程序集中有“基本”编译视图，所以我们实现了一个约定，视图引擎将首先查看web应用程序中的PosViews/{ordering mode}/{controller}/{view}路径。如果未找到视图-则它将在传统/视图/控制器/视图中查看。这里的技巧是后者是位于另一个类库中的虚拟路径

这允许我们“覆盖”应用程序的现有视图

    private void LocatorConfig()
    {
        //{0} = View Name
        //{1} = ControllerName
        //{2} = Area Name
        AreaViewLocationFormats = new[]
        {
            //First look in the hosting application area folder / Views / ordering type
            //Areas/{AreaName}/{OrderType}/{ControllerName}/{ViewName}.cshtml
            "PosAreas/{2}/Views/%1/{1}/{0}.cshtml",

            //Next look in the hosting application area folder / Views / ordering type / Shared
            //Areas/{AreaName}/{OrderType}/{ControllerName}/{ViewName}.cshtml
            "PosAreas/{2}/Views/%1/Shared/(0}.cshtml",

            //Next look in the POS Areas Shared
            "PosAreas/{2}/Views/Shared/(0}.cshtml",

            //Finally look in the IMS.POS.Web.Views.Core assembly
            "Areas/{2}/Views/{1}/{0}.cshtml"
        };

        //Same format logic
        AreaMasterLocationFormats = AreaViewLocationFormats;

        AreaPartialViewLocationFormats = new[]
        {
             //First look in the hosting application area folder / Views / ordering type
            //Areas/{AreaName}/{OrderType}/{ControllerName}/Partials/{PartialViewName}.cshtml
            "PosAreas/{2}/Views/%1/{1}/Partials/{0}.cshtml",

            //Next look in the hosting application area folder / Views / ordering type / Shared
            //Areas/{AreaName}/{OrderType}/{ControllerName}/{ViewName}.cshtml
            "PosAreas/{2}/Views/%1/Shared/(0}.cshtml",

            //Next look in the hosting application shared folder
            "PosAreas/{2}/Views/Shared/(0}.cshtml",

            //Finally look in the IMS.POS.Web.Views.Core
            "Areas/{2}/Views/{1}/{0}.cshtml"
        };

        ViewLocationFormats = new[]
        {
            "~/PosViews/%1/{1}/{0}.cshtml",
            "~/PosViews/%1/Shared/{0}.cshtml",
            "~/PosViews/Shared/{0}.cshtml",
            "~/Views/{1}/{0}.cshtml",
            "~/Views/Shared/{0}.cshtml"
        };

        MasterLocationFormats = ViewLocationFormats;

        PartialViewLocationFormats = new[]
        {
            "~/PosViews/%1/{1}/{0}.cshtml",
            "~/PosViews/%1/Shared/{0}.cshtml",
             "~/PosViews/Shared/{0}.cshtml",
            "~/Views/{1}/{0}.cshtml",
            "~/Views/Shared/{0}.cshtml"
        };
    }

在应用程序启动事件中注册此引擎

   public static void Configure()
    {
        var engine = new PosPrecompileEngine(typeof(ViewEngineConfig).Assembly)
        {
            UsePhysicalViewsIfNewer = true,
            PreemptPhysicalFiles = true
        };
        ViewEngines.Engines.Add(engine);

        // StartPage lookups are done by WebPages.
        VirtualPathFactoryManager.RegisterVirtualPathFactory(engine);
    }

这是最后一把钥匙。当RazorGenerator安装后，view NuGet-您将得到这个启动类，该类将在启动时运行

[assembly: WebActivatorEx.PostApplicationStartMethod(typeof(Views.Core.RazorGeneratorMvcStart), "Start")]


public static class RazorGeneratorMvcStart
{
    public static void Start()
    {
        var engine = new PrecompiledMvcEngine(typeof(RazorGeneratorMvcStart).Assembly)
        {
            UsePhysicalViewsIfNewer = true,
            PreemptPhysicalFiles = true
        };
        ViewEngines.Engines.Add(engine);

        // StartPage lookups are done by WebPages.
        VirtualPathFactoryManager.RegisterVirtualPathFactory(engine);
    }
}

默认情况下-RazorGenerator将ViewEngine添加到集合中的第一个

ViewEngines.Engines.Insert(0,engine);

您需要将其更改为“添加”

ViewEngines.Engines.Add(engine);

因此，它最后添加到引擎中-这样，您的自定义ViewEngine将首先用于定位视图

这种方法允许您在多个应用程序中重用视图，同时允许覆盖该视图的方法

对于大多数应用程序来说，这可能是杀伤力过大了——正如我在问题中提到的那样——这是我们用来开发多个客户端应用程序的基础产品。尝试实现重用，同时在每个客户机的基础上保持一定程度的灵活性，这是我们试图实现的目标