//******************************************************************************************************//  RazorView.cs - Gbtc////  Copyright © 2016, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may not use this//  file except in compliance with the License. You may obtain a copy of the License at:////      http://opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  01/13/2016 - J. Ritchie Carroll//       Generated original version of source code.////****************************************************************************************************** using System;using System.Collections.Generic;using System.Net.Http;using System.Threading;using System.Threading.Tasks;using System.Web;using GSF.Collections;using GSF.Data;using GSF.Web.Hosting;using GSF.Web.Security;using RazorEngine.Templating; // ReSharper disable StaticMemberInGenericTypenamespace GSF.Web.Model{    /// <summary>    /// Defines a view class for data context based Razor template implementations.    /// </summary>    public class RazorView    {        #region [ Members ]         // Fields        private readonly IRazorEngine m_razorEngine;        private readonly DynamicViewBag m_viewBag = new DynamicViewBag();        private Dictionary<string, string> m_parameters;         #endregion         #region [ Constructors ]         /// <summary>        /// Creates a new <see cref="RazorView"/>.        /// </summary>        /// <param name="razorEngine"><see cref="IRazorEngine"/> instance to use.</param>        /// <param name="templateName">Name of template file, typically a .cshtml or .vbhtml file.</param>        /// <param name="exceptionHandler">Delegate to handle exceptions, if any.</param>        public RazorView(IRazorEngine razorEngine, string templateName, Action<Exception> exceptionHandler = null) : this(razorEngine, templateName, null, null, null, null, null, exceptionHandler)        {        }         /// <summary>        /// Creates a new <see cref="RazorView"/>.        /// </summary>        /// <param name="razorEngine"><see cref="IRazorEngine"/> instance to use.</param>        /// <param name="templateName">Name of template file, typically a .cshtml or .vbhtml file.</param>        /// <param name="model">Reference to model to use when rendering template.</param>        /// <param name="modelType">Type of <paramref name="model"/>.</param>        /// <param name="pagedViewModelDataType">Type of data class for views based on paged view model, if any.</param>        /// <param name="pagedViewModelHubType">Type of SignalR hub for views based on paged view model, if any.</param>        /// <param name="database"><see cref="AdoDataConnection"/> to use, if any.</param>        /// <param name="exceptionHandler">Delegate to handle exceptions, if any.</param>        /// <param name="webServerOptions">Web server options currently in use.</param>        public RazorView(IRazorEngine razorEngine, string templateName, object model = null, Type modelType = null, Type pagedViewModelDataType = null, Type pagedViewModelHubType = null, AdoDataConnection database = null, Action<Exception> exceptionHandler = null, ReadonlyWebServerOptions webServerOptions = null)        {            m_razorEngine = razorEngine;            TemplateName = templateName;            Model = model;            ModelType = modelType;            PagedViewModelDataType = pagedViewModelDataType;            PagedViewModelHubType = pagedViewModelHubType;            Database = database;            ExceptionHandler = exceptionHandler;            WebServerOptions = webServerOptions;        }         #endregion         #region [ Properties ]         /// <summary>        /// Gets or sets name of template file.        /// </summary>        public string TemplateName { get; set; }         /// <summary>        /// Gets or sets reference to model to use when rendering template.        /// </summary>        public object Model { get; set; }         /// <summary>        /// Gets or sets type of <see cref="Model"/>.        /// </summary>        public Type ModelType { get; set; }         /// <summary>        /// Gets or sets type of data model for views based on paged view model.        /// </summary>        public Type PagedViewModelDataType { get; set; }         /// <summary>        /// Gets or sets type of SignalR hub for views based on paged view model.        /// </summary>        public Type PagedViewModelHubType { get; set; }         /// <summary>        /// Gets reference to view bag used when rendering template.        /// </summary>        public dynamic ViewBag => m_viewBag;         /// <summary>        /// Gets query string parameter specified by <paramref name="key"/>.        /// </summary>        /// <param name="key">Name of query string parameter to retrieve.</param>        /// <returns>Query string parameter specified by <paramref name="key"/>.</returns>        public string this[string key] => Parameters[key];         /// <summary>        /// Gets a dictionary of query string parameters passed to rendered view.        /// </summary>        public Dictionary<string, string> Parameters        {            get            {                if ((object)m_parameters == null)                {                    HttpRequestMessage request = ViewBag.Request;                    m_parameters = HttpUtility.ParseQueryString(request.RequestUri.Query).ToDictionary();                }                 return m_parameters;            }        }         /// <summary>        /// Gets reference to <see cref="IRazorEngine"/> used by this <see cref="RazorView"/>.        /// </summary>        public IRazorEngine RazorEngine => m_razorEngine;         /// <summary>        /// Gets or sets database connection to provide to <see cref="DataContext"/>, if any.        /// </summary>        public AdoDataConnection Database { get; set; }         /// <summary>        /// Gets or sets delegate used to handle exceptions.        /// </summary>        public Action<Exception> ExceptionHandler { get; set; }         /// <summary>        /// Gets or sets <see cref="IRazorEngine"/> to use for the <see cref="DataContext"/> provided to the view; defaults to <c>null</c>.        /// </summary>        /// <remarks>        /// This should typically not be changed. When value is <c>null</c>, the data context will use the default        /// <see cref="RazorEngine{TLanguage}"/> instance for <see cref="CSharpEmbeddedResource"/> which is used        /// to generate template based HTML input fields for a view. The default HTML input templates are defined        /// as embedded resources in GSF.Web.        /// </remarks>        public IRazorEngine DataContextEngine { get; set; }         /// <summary>        /// Gets or sets the web server options currently in use.        /// </summary>        public ReadonlyWebServerOptions WebServerOptions { get; set; }         #endregion         #region [ Methods ]         /// <summary>        /// Compiles and executes view template.        /// </summary>        /// <returns>Rendered result.</returns>        public string Execute()        {            using (DataContext dataContext = new DataContext(Database, razorEngine: DataContextEngine, exceptionHandler: ExceptionHandler))            {                if ((object)PagedViewModelDataType != null && (object)PagedViewModelHubType != null)                    dataContext.ConfigureView(PagedViewModelDataType, PagedViewModelHubType, null as string, m_viewBag);                 m_viewBag.AddValue("DataContext", dataContext);                return m_razorEngine.RunCompile(TemplateName, ModelType, Model, m_viewBag);            }        }         /// <summary>        /// Compiles and executes view template for specified request message and post data.        /// </summary>        /// <param name="request">HTTP request message.</param>        /// <param name="response">HTTP response message.</param>        /// <returns>Rendered result.</returns>        public string Execute(HttpRequestMessage request, HttpResponseMessage response)        {            using (DataContext dataContext = new DataContext(Database, razorEngine: DataContextEngine, exceptionHandler: ExceptionHandler))            {                // Need to add the security principal to the view bag before configuring the view                m_viewBag.AddValue("SecurityPrincipal", request.GetRequestContext().Principal);                 if ((object)PagedViewModelDataType != null && (object)PagedViewModelHubType != null)                    dataContext.ConfigureView(PagedViewModelDataType, PagedViewModelHubType, request, m_viewBag);                 m_viewBag.AddValue("Application", s_applicationCache);                m_viewBag.AddValue("DataContext", dataContext);                m_viewBag.AddValue("Request", request);                m_viewBag.AddValue("Response", response);                m_viewBag.AddValue("IsPost", request.Method == HttpMethod.Post);                m_viewBag.AddValue("WebServerOptions", WebServerOptions);                m_viewBag.AddValue("AuthenticationOptions", request.GetAuthenticationOptions());                 DynamicViewBag sessionState;                 // See if a client session has been defined for this execution request                if (SessionHandler.TryGetSessionState(request, WebServerOptions?.SessionToken, out sessionState))                    m_viewBag.AddValue("Session", sessionState);                 return m_razorEngine.RunCompile(TemplateName, ModelType, Model, m_viewBag);            }        }         /// <summary>        /// Asynchronously compiles and executes view template for specified request message and post data.        /// </summary>        /// <param name="request">HTTP request message.</param>        /// <param name="response">HTTP response message.</param>        /// <param name="cancellationToken">Propagates notification from client that operations should be canceled.</param>        /// <returns>Task that will provide rendered result.</returns>        public Task<string> ExecuteAsync(HttpRequestMessage request, HttpResponseMessage response, CancellationToken cancellationToken)        {            return Task.Run(() => Execute(request, response), cancellationToken);        }         #endregion         #region [ Static ]         // Static Fields        private static readonly DynamicViewBag s_applicationCache;         // Static Constructor        static RazorView()        {            s_applicationCache = new DynamicViewBag();        }         #endregion        }}