Render View programmatically into a string

Question

I would like to get the html code a view would generate in a string, modify it in my controller, then add it to my JsonResult.

I found code that would do what i\'m t

Answer 1

Mike Hadlow blogged about a function called CaptureActionHtml() that does this. I've used it to compose large reports out of smaller, more manageable reports and then pass them around.

http://mikehadlow.blogspot.com/2008/06/mvc-framework-capturing-output-of-view_05.html

using System;
using System.IO;
using System.Web;
using System.Web.Mvc;

namespace Suteki.Common.Extensions
{
    public static class ControllerExtensions
    {
        /// 

        /// Captures the HTML output by a controller action that returns a ViewResult
        /// 
        /// The type of controller to execute the action on
        /// The controller
        /// The action to execute
        /// The HTML output from the view
        public static string CaptureActionHtml(
            this TController controller,
            Func action)
            where TController : Controller
        {
            return controller.CaptureActionHtml(controller, null, action);
        }

        /// 

        /// Captures the HTML output by a controller action that returns a ViewResult
        /// 
        /// The type of controller to execute the action on
        /// The controller
        /// The master page to use for the view
        /// The action to execute
        /// The HTML output from the view
        public static string CaptureActionHtml(
            this TController controller,
            string masterPageName,
            Func action)
            where TController : Controller
        {
            return controller.CaptureActionHtml(controller, masterPageName, action);
        }

        /// 

        /// Captures the HTML output by a controller action that returns a ViewResult
        /// 
        /// The type of controller to execute the action on
        /// The current controller
        /// The controller which has the action to execute
        /// The action to execute
        /// The HTML output from the view
        public static string CaptureActionHtml(
            this Controller controller,
            TController targetController, 
            Func action)
            where TController : Controller
        {
            return controller.CaptureActionHtml(targetController, null, action);
        }

        /// 

        /// Captures the HTML output by a controller action that returns a ViewResult
        /// 
        /// The type of controller to execute the action on
        /// The current controller
        /// The controller which has the action to execute
        /// The name of the master page for the view
        /// The action to execute
        /// The HTML output from the view
        public static string CaptureActionHtml(
            this Controller controller,
            TController targetController, 
            string masterPageName,
            Func action)
            where TController : Controller
        {
            if (controller == null)
            {
                throw new ArgumentNullException("controller");
            }
            if (targetController == null)
            {
                throw new ArgumentNullException("targetController");
            }
            if (action == null)
            {
                throw new ArgumentNullException("action");
            }

            // pass the current controller context to orderController
            var controllerContext = controller.ControllerContext;
            targetController.ControllerContext = controllerContext;

            // replace the current context with a new context that writes to a string writer
            var existingContext = System.Web.HttpContext.Current;
            var writer = new StringWriter();
            var response = new HttpResponse(writer);
            var context = new HttpContext(existingContext.Request, response) {User = existingContext.User};
            System.Web.HttpContext.Current = context;

            // execute the action
            var viewResult = action(targetController);

            // change the master page name
            if (masterPageName != null)
            {
                viewResult.MasterName = masterPageName;
            }

            // we have to set the controller route value to the name of the controller we want to execute
            // because the ViewLocator class uses this to find the correct view
            var oldController = controllerContext.RouteData.Values["controller"];
            controllerContext.RouteData.Values["controller"] = typeof(TController).Name.Replace("Controller", "");

            // execute the result
            viewResult.ExecuteResult(controllerContext);

            // restore the old route data
            controllerContext.RouteData.Values["controller"] = oldController;

            // restore the old context
            System.Web.HttpContext.Current = existingContext;

            return writer.ToString();
        }
    }
}