Question

I am starting a new project in Asp.net MVC 2.
I have been mostly a webforms developer and have limited exposure to Asp.Net MVC and hence this is probably a noob question.

My situation is as follows:
I have a create page for saving some data to the DB.
The view for this page is not strongly bound / typed – so the way I am extracting the data from the view is by looking at the POST parameters.

Incase there is an error (data validation, etc), I need to send the user back to the previous page with everything filled in the way it was and displaying the message.

On webforms, this got handled automatically due to the view state – but how can I go about doing the same here?

A code example can be as follows:

View:

<% using (Html.BeginForm("Create", "Question", FormMethod.Post)) { %>
<div>
Title: <%: Html.TextBox("Title", "", new { @style="width:700px" })%>
</div>
<div>
Question: <%: Html.TextBox("Question", "", new { @style="width:700px" })%>
</div>
<input type="submit" value="Submit" />
<% } %>

Controller:

    [HttpPost]
    [ValidateInput(false)]
    public ActionResult Create() {
        Question q = new Question();
        q.Title = Request.Form["Title"];
        q.Text = Request.Form["Question"];
        if(q.Save()) {
            return RedirectToAction("Details", new { id = q.Id });
        }
        else {
            // Need to send back to Create page with data filled in
            // Help needed here
        }
    }

Thanks.

Answer 1

You could simply return the View in case of error. This will preserve the context.

[HttpPost]
[ValidateInput(false)]
public ActionResult Create(Question q) {
    if(q.Save()) {
        return RedirectToAction("Details", new { id = q.Id });
    }
    else {
        // Need to send back to Create page with data filled in
        // Help needed here
        return View();
        // If the view is located on some other controller you could
        // specify its location:
        // return View("~/Views/Question/Create.aspx");
    }
}

Also I would recommend you to use strongly typed views along with the strongly typed helpers. Notice how I used a Question object directly as action parameter. This is equivalent to the code you have written in which you were manually extracting and building this object. The model binder does this job automatically for you.