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 talking about from a partial. I would like to do it from an aspx View though.
— Extra explanation:
Let’s say I have a page Frame.aspx that /Controller/Frame will return
I would like to get my hand on the response before it out so I can to wrap it with jsonp.
I do not wish to edit the return result in code every time, this is why I want to load the view programmatically.
/Controller/Frame currently returns Frame.aspx’s content: <html><body>hello</body></html>
Let’s say there’s a function that renders a view in a string builder
StringBuilder sb = new StringBuilder(); RenderView(sb, "Frame");
now take sb and wrap it with jsonp:
public JsonResult Frame(string callback)
{
StringBuilder sb = new StringBuilder();
RenderView(sb, "Frame");
return new JsonResult
{
Data = "(function() { " + callback + "(" + clientResponse + "); })();"
,
JsonRequestBehavior = JsonRequestBehavior.AllowGet
};
}
Answers:
Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.
Method 1
This works like a charm (got it through SO).
I use it like this:
public class OfferController : Controller
{
[HttpPost]
public JsonResult EditForm(int Id)
{
var model = Mapper.Map<Offer, OfferEditModel>(_repo.GetOffer(Id));
return Json(new { status = "ok", partial = this.RenderPartialViewToString("Edit", model) });
}
}
public static partial class ControllerExtensions
{
public static string RenderPartialViewToString(this ControllerBase controller, string partialPath, object model)
{
if (string.IsNullOrEmpty(partialPath))
partialPath = controller.ControllerContext.RouteData.GetRequiredString("action");
controller.ViewData.Model = model;
using (StringWriter sw = new StringWriter())
{
ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(controller.ControllerContext, partialPath);
ViewContext viewContext = new ViewContext(controller.ControllerContext, viewResult.View, controller.ViewData, controller.TempData, sw);
// copy model state items to the html helper
foreach (var item in viewContext.Controller.ViewData.ModelState)
if (!viewContext.ViewData.ModelState.Keys.Contains(item.Key))
{
viewContext.ViewData.ModelState.Add(item);
}
viewResult.View.Render(viewContext, sw);
return sw.GetStringBuilder().ToString();
}
}
}
Method 2
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
{
/// <summary>
/// Captures the HTML output by a controller action that returns a ViewResult
/// </summary>
/// <typeparam name="TController">The type of controller to execute the action on</typeparam>
/// <param name="controller">The controller</param>
/// <param name="action">The action to execute</param>
/// <returns>The HTML output from the view</returns>
public static string CaptureActionHtml<TController>(
this TController controller,
Func<TController, ViewResult> action)
where TController : Controller
{
return controller.CaptureActionHtml(controller, null, action);
}
/// <summary>
/// Captures the HTML output by a controller action that returns a ViewResult
/// </summary>
/// <typeparam name="TController">The type of controller to execute the action on</typeparam>
/// <param name="controller">The controller</param>
/// <param name="masterPageName">The master page to use for the view</param>
/// <param name="action">The action to execute</param>
/// <returns>The HTML output from the view</returns>
public static string CaptureActionHtml<TController>(
this TController controller,
string masterPageName,
Func<TController, ViewResult> action)
where TController : Controller
{
return controller.CaptureActionHtml(controller, masterPageName, action);
}
/// <summary>
/// Captures the HTML output by a controller action that returns a ViewResult
/// </summary>
/// <typeparam name="TController">The type of controller to execute the action on</typeparam>
/// <param name="controller">The current controller</param>
/// <param name="targetController">The controller which has the action to execute</param>
/// <param name="action">The action to execute</param>
/// <returns>The HTML output from the view</returns>
public static string CaptureActionHtml<TController>(
this Controller controller,
TController targetController,
Func<TController, ViewResult> action)
where TController : Controller
{
return controller.CaptureActionHtml(targetController, null, action);
}
/// <summary>
/// Captures the HTML output by a controller action that returns a ViewResult
/// </summary>
/// <typeparam name="TController">The type of controller to execute the action on</typeparam>
/// <param name="controller">The current controller</param>
/// <param name="targetController">The controller which has the action to execute</param>
/// <param name="masterPageName">The name of the master page for the view</param>
/// <param name="action">The action to execute</param>
/// <returns>The HTML output from the view</returns>
public static string CaptureActionHtml<TController>(
this Controller controller,
TController targetController,
string masterPageName,
Func<TController, ViewResult> 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();
}
}
}
Method 3
Here is another workaround for capturing the view in MVC 2.0 and >net 4.0. I just added few lines of code to Andrews original content.
public static class ControllerExtensions
{
/// <summary>
/// Captures the HTML output by a controller action that returns a ViewResult
/// </summary>
/// <typeparam name="TController">The type of controller to execute the action on</typeparam>
/// <param name="controller">The controller</param>
/// <param name="action">The action to execute</param>
/// <returns>The HTML output from the view</returns>
public static string CaptureActionHtml<TController>(
this TController controller,
Func<TController, ViewResult> action)
where TController : Controller
{
return controller.CaptureActionHtml(controller, null, action);
}
/// <summary>
/// Captures the HTML output by a controller action that returns a ViewResult
/// </summary>
/// <typeparam name="TController">The type of controller to execute the action on</typeparam>
/// <param name="controller">The controller</param>
/// <param name="masterPageName">The master page to use for the view</param>
/// <param name="action">The action to execute</param>
/// <returns>The HTML output from the view</returns>
public static string CaptureActionHtml<TController>(
this TController controller,
string masterPageName,
Func<TController, ViewResult> action)
where TController : Controller
{
return controller.CaptureActionHtml(controller, masterPageName, action);
}
/// <summary>
/// Captures the HTML output by a controller action that returns a ViewResult
/// </summary>
/// <typeparam name="TController">The type of controller to execute the action on</typeparam>
/// <param name="controller">The current controller</param>
/// <param name="targetController">The controller which has the action to execute</param>
/// <param name="action">The action to execute</param>
/// <returns>The HTML output from the view</returns>
public static string CaptureActionHtml<TController>(
this Controller controller,
TController targetController,
Func<TController, ViewResult> action)
where TController : Controller
{
return controller.CaptureActionHtml(targetController, null, action);
}
/// <summary>
/// Captures the HTML output by a controller action that returns a ViewResult
/// </summary>
/// <typeparam name="TController">The type of controller to execute the action on</typeparam>
/// <param name="controller">The current controller</param>
/// <param name="targetController">The controller which has the action to execute</param>
/// <param name="masterPageName">The name of the master page for the view</param>
/// <param name="action">The action to execute</param>
/// <returns>The HTML output from the view</returns>
///
public static string CaptureActionHtml<TController>(this Controller controller, TController targetController, string masterPageName, Func<TController, ViewResult> 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 = HttpContext.Current;
var writer = new StringWriter();
var response = new HttpResponse(writer);
var context = new HttpContext(existingContext.Request, response) { User = existingContext.User };
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);
StringWriter sw = new StringWriter();
var xx = targetController.TempData["pdf"];
//var viewContext = new ViewContext(controllerContext, viewResult.View, new ViewDataDictionary(targetController.ViewData.Model), new TempDataDictionary(), sw);
var viewContext = new ViewContext(controllerContext, viewResult.View, viewResult.ViewData, new TempDataDictionary(), sw);
viewResult.View.Render(viewContext, HttpContext.Current.Response.Output);
response.Flush();
// restore the old route data
controllerContext.RouteData.Values["controller"] = oldController;
// restore the old context
HttpContext.Current = existingContext;
return sw.ToString();
}
}
}
cheers!!
All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0