Detailed description of ASP. net mvc prg data verification

Here we will talk about ASP. net mvc prg data verification, mainly for reference to some foreign articles on PRG data verification, I hope to help you.

My philosophy:

Since it is ASP. net mvc, PRG must be used. However, a simple PRG cannot display Html. ValidationMessage on the input page. The other is that the previous data is cleared or initialized.

Think about how miserable it is if I have been playing for half a day. It's strange that your visitor is not so angry.

Okay, Google, find the http://weblogs.asp.net/rashid/archive/2009/04/01/asp-net-mvc-best-practices-part-1.aspx

A: I don't know his name. I don't know the copyright statement in English, so there is no signature for this link. Who knows him and asks him to write a copyright statement for C # Or VB. NET? Thank you.

It doesn't matter if the English is not good. Let's look at the 13th point: Use PRG Pattern for Data Modification.

 
 

  
  
Controller  
  
  
[AcceptVerbs(HttpVerbs.Get), OutputCache(CacheProfile = "Dashboard"), StoryListFilter, ImportModelStateFromTempData]  
  
  
public ActionResult Dashboard(string userName, StoryListTab tab, OrderBy orderBy, int? page)  
  
  
{  
  
  
    //Other Codes  
  
  
    return View();  
  
  
}  
  
  
 
  
  
[AcceptVerbs(HttpVerbs.Post), ExportModelStateToTempData]  
  
  
public ActionResult Submit(string userName, string url)  
  
  
{  
  
  
    if (ValidateSubmit(url))  
  
  
    {  
  
  
        try 
  
  
        {  
  
  
            _storyService.Submit(userName, url);  
  
  
        }  
  
  
        catch (Exception e)  
  
  
        {  
  
  
            ModelState.AddModelError(ModelStateException, e);  
  
  
        }  
  
  
    }  
  
  
 
  
  
    return Redirect(Url.Dashboard());  
  
  
} 
 
 

Two custom actionfilters are defined. A, the author seems to have typed a wrong word. Don't worry.

 
 

  
  
ModelStateTempDataTransfer  
  
  
public abstract class ModelStateTempDataTransfer : ActionFilterAttribute  
  
  
{  
  
  
    protected static readonly string Key = typeof(ModelStateTempDataTransfer).FullName;  
  
  
}  
  
  
 
  
  
public class ExportModelStateToTempData : ModelStateTempDataTransfer  
  
  
{  
  
  
    public override void OnActionExecuted(ActionExecutedContext filterContext)  
  
  
    {  
  
  
        //Only export when ModelState is not valid  
  
  
        if (!filterContext.Controller.ViewData.ModelState.IsValid)  
  
  
        {  
  
  
            //Export if we are redirecting  
  
  
            if ((filterContext.Result is RedirectResult) || (filterContext.Result is RedirectToRouteResult))  
  
  
            {  
  
  
                filterContext.Controller.TempData[Key] = filterContext.Controller.ViewData.ModelState;  
  
  
            }  
  
  
        }  
  
  
 
  
  
        base.OnActionExecuted(filterContext);  
  
  
    }  
  
  
}  
  
  
 
  
  
public class ImportModelStateFromTempData : ModelStateTempDataTransfer  
  
  
{  
  
  
    public override void OnActionExecuted(ActionExecutedContext filterContext)  
  
  
    {  
  
  
        ModelStateDictionary modelState = filterContext.Controller.TempData[Key] as ModelStateDictionary;  
  
  
 
  
  
        if (modelState != null)  
  
  
        {  
  
  
            //Only Import if we are viewing  
  
  
            if (filterContext.Result is ViewResult)  
  
  
            {  
  
  
                filterContext.Controller.ViewData.ModelState.Merge(modelState);  
  
  
            }  
  
  
            else  
  
  
            {  
  
  
                //Otherwise remove it.  
  
  
                filterContext.Controller.TempData.Remove(Key);  
  
  
            }  
  
  
        }  
  
  
 
  
  
        base.OnActionExecuted(filterContext);  
  
  
    }  
  
  
} 
 
 

I used VB. NET and directly transferred it to my project using tools. I didn't know how to use the source code for a try.

Haha, it succeeded. The cute Html. ValidationMessage is coming.

However, data is still not cleared or initialized.

This is terrible. Google, Baidu, or I am still looking for it in my blog. I guess the method I am looking for is wrong. Otherwise, no one will issue any problems that many people have encountered.

Finally in the garden of the group to find the http://space.cnblogs.com/group/topic/7919/ third reply said ModelState. SetModelValue method, take a try, really good.

So I modified the ExportModelStateToTempData in the two actionfilters mentioned earlier. The Code is as follows:

 
 

  
  
Code  
  
  
    Public Overrides Sub OnActionExecuted(ByVal pFilterContext As ActionExecutedContext)  
  
  
        If Not pFilterContext.Controller.ViewData.ModelState.IsValid Then  
  
  
            If TypeOf (pFilterContext.Result) Is RedirectResult OrElse TypeOf (pFilterContext.Result) Is RedirectToRouteResult Then  
  
  
                If pFilterContext.HttpContext.Request.Form.Count > 0 Then  
  
  
                    Dim tFormCollection As New FormCollection(pFilterContext.HttpContext.Request.Form)  
  
  
                    For Each fKey As String In tFormCollection  
  
  
                        pFilterContext.Controller.ViewData.ModelState.SetModelValue(fKey, tFormCollection.ToValueProvider(fKey))  
  
  
                    Next  
  
  
                    pFilterContext.Controller.TempData(mKey) = pFilterContext.Controller.ViewData.ModelState  
  
  
                End If  
  
  
            End If  
  
  
        End If  
  
  
        MyBase.OnActionExecuted(pFilterContext)  
  
  
    End Sub 
 
 

In the end, because I use VB. net is case-insensitive, so each of my parameters starts with p, temporary variables start with t, and internal loops start with f.

Original article title: Asp. Net Mvc PRG data verification

Link: http://www.cnblogs.com/yexuan/archive/2009/09/18/1568929.html

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