Comments on: RenderPartial to String in ASP.NET MVC Beta http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/ Wed, 26 Jan 2011 18:41:27 +0000 hourly 1 http://wordpress.org/?v=3.3 By: xinqikan http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-1364 xinqikan Wed, 17 Nov 2010 08:06:22 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-1364 Is ASP.NET MVC's FileStreamResult less efficient than writing directly to the Response Output Stream, or am I missing something? Is ASP.NET MVC’s FileStreamResult less efficient than writing directly to the Response Output Stream, or am I missing something?

]]> By: Render a view as a string — HTMLCoderHelper.com http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-1362 Render a view as a string — HTMLCoderHelper.com Sun, 14 Nov 2010 10:40:22 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-1362 [...] RenderPartial to String in ASP.NET MVC Beta If I use this example, I receive the "Cannot redirect after HTTP headers have been sent.". [...] [...] RenderPartial to String in ASP.NET MVC Beta If I use this example, I receive the "Cannot redirect after HTTP headers have been sent.". [...]

]]> By: Wessel http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-1339 Wessel Fri, 20 Aug 2010 09:33:57 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-1339 The solution is very simple. Create a new Viewclass based on the WebFormView, and use that as the ViewEnging for rendering (by returning this View in the CreatePartialView and CreateView methods of a custom WebFormViewEngine). Override the Render method in your new Viewclass and create a new TextWriter. Store the viewContent.Writer and set the viewContent.Writer to the newly created TextWriter. Call MyBase.Render(viewContext,writer). The writer is ignored, but you just changed the writer of the viewContext so any output goes there and not to the Response! Restore the viewContext.Writer. You can now use the content of the newly created TextWriter and do anything you like. Finally write the changed content to the old viewContent.Writer (which writes to Response). Performance does not degrade as far as I can tell and this works for partialrendering as well as for normal pages. Basically for all view rendered output. Example: Imports System.IO Public Class CustomRenderView Inherits WebFormView Public Sub New(ByVal viewPath As String) MyBase.New(viewPath) End Sub Public Sub New(ByVal viewPath As String, ByVal masterPath As String) MyBase.New(viewPath, masterPath) End Sub Public Overrides Sub Render(ByVal viewContext As System.Web.Mvc.ViewContext, ByVal writer As System.IO.TextWriter) Dim newWriter As TextWriter = New StringWriter() Dim oldWriter As TextWriter = viewContext.Writer viewContext.Writer = newWriter MyBase.Render(viewContext, newWriter) 'use newWriter in case MS changes its mind to ignore it... viewContext.Writer = oldWriter Dim pageSource As String = newWriter.ToString() 'do something with the generated output in pageSource 'write changed output to the original viewContext.Writer (goes to Response object) oldWriter.Write(pageSource) End Sub End Class The solution is very simple.

Create a new Viewclass based on the WebFormView, and use that as the ViewEnging for rendering (by returning this View in the CreatePartialView and CreateView methods of a custom WebFormViewEngine).

Override the Render method in your new Viewclass and create a new TextWriter.
Store the viewContent.Writer and set the viewContent.Writer to the newly created TextWriter.
Call MyBase.Render(viewContext,writer).
The writer is ignored, but you just changed the writer of the viewContext so any output goes there and not to the Response!

Restore the viewContext.Writer.

You can now use the content of the newly created TextWriter and do anything you like.
Finally write the changed content to the old viewContent.Writer (which writes to Response).

Performance does not degrade as far as I can tell and this works for partialrendering as well as for normal pages.
Basically for all view rendered output.

Example:

Imports System.IO

Public Class CustomRenderView
Inherits WebFormView

Public Sub New(ByVal viewPath As String)
MyBase.New(viewPath)
End Sub

Public Sub New(ByVal viewPath As String, ByVal masterPath As String)
MyBase.New(viewPath, masterPath)
End Sub

Public Overrides Sub Render(ByVal viewContext As System.Web.Mvc.ViewContext, ByVal writer As System.IO.TextWriter)
Dim newWriter As TextWriter = New StringWriter()

Dim oldWriter As TextWriter = viewContext.Writer
viewContext.Writer = newWriter

MyBase.Render(viewContext, newWriter) ‘use newWriter in case MS changes its mind to ignore it…
viewContext.Writer = oldWriter

Dim pageSource As String = newWriter.ToString()
‘do something with the generated output in pageSource

‘write changed output to the original viewContext.Writer (goes to Response object)
oldWriter.Write(pageSource)
End Sub

End Class

]]> By: Kevin http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-1005 Kevin Tue, 13 Oct 2009 00:35:56 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-1005 Hello all, I've updated this post to link to a new article, which makes renderpartial to string substantially easier in ASP.NET MVC Hello all, I’ve updated this post to link to a new article, which makes renderpartial to string substantially easier in ASP.NET MVC

]]> By: Dan Atkinson http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-962 Dan Atkinson Fri, 07 Aug 2009 08:26:41 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-962 Lorenz, If you look up at the comment on January 28th, you'll see that I mentioned this. :) Thanks, Dan (the guy who originally created the SO question!). Lorenz,

If you look up at the comment on January 28th, you’ll see that I mentioned this. :)

Thanks,

Dan (the guy who originally created the SO question!).

]]> By: Lorenz Cuno Klopfenstein http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-961 Lorenz Cuno Klopfenstein Thu, 06 Aug 2009 20:47:48 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-961 Hello people, I found a new solution that doesn't involve messing with the filters of the current HttpResponse and shouldn't have problems with ContentType and other headers (it isn't quite as elegant as Martin's solution, but it also works for views that inherit from ViewPage instead of UserControls only). Here it is on StackOverflow: http://stackoverflow.com/questions/483091/render-a-view-as-a-string/1241257#1241257 Hope it helps. :) Greetings Hello people,
I found a new solution that doesn’t involve messing with the filters of the current HttpResponse and shouldn’t have problems with ContentType and other headers (it isn’t quite as elegant as Martin’s solution, but it also works for views that inherit from ViewPage instead of UserControls only).
Here it is on StackOverflow: http://stackoverflow.com/questions/483091/render-a-view-as-a-string/1241257#1241257

Hope it helps. :) Greetings

]]> By: Martin http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-849 Martin Wed, 17 Jun 2009 21:37:41 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-849 Jon Kruger: My approach doenst have any problems with content-type. Anyway, i just wanted to add that nesting the custom render partial works just fine (i use it for a email template service). If you need to make the helpers work (html/ajax/url) remember to call InitHelpers() on the ViewPage (and add ViewContext / ControllerContext). Jon Kruger: My approach doenst have any problems with content-type.

Anyway, i just wanted to add that nesting the custom render partial works just fine (i use it for a email template service).

If you need to make the helpers work (html/ajax/url) remember to call InitHelpers() on the ViewPage (and add ViewContext / ControllerContext).

]]> By: Jon Kruger http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-846 Jon Kruger Sun, 07 Jun 2009 02:59:25 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-846 I think I found a way around the limitation where you can't change the content type. It seems to be working for me so far. <a href="http://jonkruger.com/blog/2009/06/06/aspnet-mvc-rendering-a-partial-view-to-a-string/" rel="nofollow"> http://jonkruger.com/blog/2009/06/06/aspnet-mvc-rendering-a-partial-view-to-a-string/</a> I think I found a way around the limitation where you can’t change the content type. It seems to be working for me so far.


http://jonkruger.com/blog/2009/06/06/aspnet-mvc-rendering-a-partial-view-to-a-string/

]]> By: Jon http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-842 Jon Tue, 26 May 2009 15:42:05 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-842 Thank You,Thank You,Thank You! This is exactly what I needed. I am returning a JSONResult now with the output from my Partial! Thank You,Thank You,Thank You! This is exactly what I needed. I am returning a JSONResult now with the output from my Partial!

]]> By: Maico Tamayo http://www.brightmix.com/blog/how-to-renderpartial-to-string-in-asp-net-mvc/comment-page-1/#comment-835 Maico Tamayo Mon, 11 May 2009 16:10:43 +0000 http://www.brightmix.com//2008/11/24/how-to-renderpartial-to-string-in-asp-net-mvc#comment-835 To Ozkan, Sorry for my late reply, I was so busy with my work, we also experienced that same problem when our company migrated from mvc beta to 1.0, and we found out to prevent this error, you must really but viewData or at least instantiate it properly for your RenderPartialString method, I don't know your situation, but in our case it worked.. It seems working, maybe the MVC team is a little strict nowadays when it comes to rendering a page with a null viewdata,I really don't know.But I hope this helps you. To Ozkan,
Sorry for my late reply, I was so busy with my work, we also experienced that same problem when our company migrated from mvc beta to 1.0, and we found out to prevent this error, you must really but viewData or at least instantiate it properly for your RenderPartialString method, I don’t know your situation, but in our case it worked.. It seems working, maybe the MVC team is a little strict nowadays when it comes to rendering a page with a null viewdata,I really don’t know.But I hope this helps you.

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