ASP .NET MVC Form fields Validation (without model)

Question

I am looking for a way to validate two fields on ASP View page. I am aware that usual way of validating form fields is to have some @model ViewModel object included on a page, where the properties of this model object would be annotated with proper annotations needed for validation. For example, annotations can be like this:

[Required(ErrorMessage = "Please add the message")]
[Display(Name = "Message")]

But, in my case, there is no model included on a page, and controller action that is being called from the form receives plane strings as method arguments. This is form code:

@using (Html.BeginForm("InsertRssFeed", "Rss", FormMethod.Post, new { @id = "insertForm", @name = "insertForm" }))
{
<!-- inside this div goes entire form for adding rssFeed, or for editing it -->
    ...
            <div class="form-group">
                <label class="col-sm-2 control-label"> Name:</label>
                <div class="col-sm-10">
                    <div class="controls">
                        @Html.Editor("Name", new { htmlAttributes = new { @class = "form-control", @id = "add_rssFeed_name" } })
                    </div>
                </div>
            </div>

                <div class="form-group">
                    <label class="col-sm-2 control-label"> URL:</label>
                    <div class="col-sm-10">
                        <div class="controls">
                            @Html.Editor("Url", new { htmlAttributes = new { @class = "form-control", @id = "add_rssFeed_Url" } })
                        </div>
                    </div>
                </div>

            </div>
        </div>
            <!-- ok and cancel buttons. they use two css classes.  button-styleCancel is grey button and button-styleOK is normal orange button -->
        <div class="modal-footer">
            <button type="button" class="button-styleCancel" data-dismiss="modal">Close</button>
            <button type="submit" class="button-styleOK" id="submitRssFeed">Save RSS Feed</button>
        </div>
}

You can see that form is sending two text fields (Name and Url) to the RssController action method, that accepts these two string parameters:

[HttpPost]
public ActionResult InsertRssFeed(string Name, string Url)
{

    if (!String.IsNullOrEmpty(Name.Trim()) & !String.IsNullOrEmpty(Url.Trim()))
    {
        var rssFeed = new RssFeed();
        rssFeed.Name = Name;
        rssFeed.Url = Url;

        using (AuthenticationManager authenticationManager = new AuthenticationManager(User))
        {
            string userSid = authenticationManager.GetUserClaim(SystemClaims.ClaimTypes.PrimarySid);
            string userUPN = authenticationManager.GetUserClaim(SystemClaims.ClaimTypes.Upn);

            rssFeedService.CreateRssFeed(rssFeed);
        }
    }

    return RedirectToAction("ReadAllRssFeeds", "Rss");
}

If the page would have model, validation would be done with @Html.ValidationSummary method, but as I said I am not using modelview object on a page. Is there a way to achieve this kind of validation without using ModelView object, and how to do that? Thanks.

Answer 1

If you are looking for server side validation you can use something like below using

ModelState.AddModelError("", "Name and Url are required fields.");

but you need to add

@Html.ValidationSummary(false)

to your razor view inside the Html.BeginForm section, then code will looks like below.

[HttpPost]
public ActionResult InsertRssFeed(string Name, string Url)
{

    if (String.IsNullOrEmpty(Name.Trim()) || String.IsNullOrEmpty(Url.Trim()))
    {
        ModelState.AddModelError("", "Name and URL are required fields.");
        return View();
    }

    var rssFeed = new RssFeed();
        rssFeed.Name = Name;
        rssFeed.Url = Url;

    using (AuthenticationManager authenticationManager = new AuthenticationManager(User))
    {
        string userSid = authenticationManager.GetUserClaim(SystemClaims.ClaimTypes.PrimarySid);
        string userUPN = authenticationManager.GetUserClaim(SystemClaims.ClaimTypes.Upn);

        rssFeedService.CreateRssFeed(rssFeed);
    }

    return RedirectToAction("ReadAllRssFeeds", "Rss");
}

If you are looking for only client side validation, then you have to use client side validation library like Jquery.

http://runnable.com/UZJ24Io3XEw2AABU/how-to-validate-forms-in-jquery-for-validation

Edited section for comment

your razor should be like this.

@using (Html.BeginForm("InsertRssFeed", "Rss", FormMethod.Post, new { @id = "insertForm", @name = "insertForm" }))
{
    @Html.ValidationSummary(false)

        <div class="form-group">
            <label class="col-sm-2 control-label"> Name:</label>
            <div class="col-sm-10">
                <div class="controls">
                    @Html.Editor("Name", new { htmlAttributes = new { @class = "form-control", @id = "add_rssFeed_name" } })
                </div>
            </div>
        </div>

            <div class="form-group">
                <label class="col-sm-2 control-label"> URL:</label>
                <div class="col-sm-10">
                    <div class="controls">
                        @Html.Editor("Url", new { htmlAttributes = new { @class = "form-control", @id = "add_rssFeed_Url" } })
                    </div>
                </div>
            </div>

        </div>
    </div>
        <!-- ok and cancel buttons. they use two css classes.  button-styleCancel is grey button and button-styleOK is normal orange button -->
    <div class="modal-footer">
        <button type="button" class="button-styleCancel" data-dismiss="modal">Close</button>
        <button type="submit" class="button-styleOK" id="submitRssFeed">Save RSS Feed</button>
    </div>
}

Hope this helps.