How do you handle multiple submit buttons in ASP.N

Question

Is there some easy way to handle multiple submit buttons from the same form? Example:

<% Html.BeginForm("MyAction", "MyController", FormMethod.Post); %>
<input type="submit" value="Send" />
<input type="submit" value="Cancel" />
<% Html.EndForm(); %>

Any idea how to do this in ASP.NET Framework Beta? All examples I've googled for have single buttons in them.

Answer 1

Just written a post about that: Multiple submit buttons with ASP.NET MVC:

Basically, instead of using ActionMethodSelectorAttribute, I am using ActionNameSelectorAttribute, which allows me to pretend the action name is whatever I want it to be. Fortunately, ActionNameSelectorAttribute does not just make me specify action name, instead I can choose whether the current action matches request.

So there is my class (btw I am not too fond of the name):

public class HttpParamActionAttribute : ActionNameSelectorAttribute {
    public override bool IsValidName(ControllerContext controllerContext, string actionName, MethodInfo methodInfo) {
        if (actionName.Equals(methodInfo.Name, StringComparison.InvariantCultureIgnoreCase))
            return true;

        if (!actionName.Equals("Action", StringComparison.InvariantCultureIgnoreCase))
            return false;

        var request = controllerContext.RequestContext.HttpContext.Request;
        return request[methodInfo.Name] != null;
    }
} 

To use just define a form like this:

<% using (Html.BeginForm("Action", "Post")) { %>
  <!— …form fields… -->
  <input type="submit" name="saveDraft" value="Save Draft" />
  <input type="submit" name="publish" value="Publish" />
<% } %> 

and controller with two methods

public class PostController : Controller {
    [HttpParamAction]
    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult SaveDraft(…) {
        //…
    }

    [HttpParamAction]
    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult Publish(…) {
        //…
    } 
}

As you see, the attribute does not require you to specify anything at all. Also, name of the buttons are translated directly to the method names. Additionally (I haven’t tried that) these should work as normal actions as well, so you can post to any of them directly.

Answer 2

I would suggest interested parties have a look at Maarten Balliauw's solution. I think it is very elegant.

In case the link dissapears, it's using the MultiButton attribute applied to a controller action to indicate which button click that action should relate to.

Answer 3

This is the technique I'd use and I don't see it here yet. The link (posted by Saajid Ismail ) that inspires this solution is http://weblogs.asp.net/dfindley/archive/2009/05/31/asp-net-mvc-multiple-buttons-in-the-same-form.aspx). It adapts Dylan Beattie's answer to do localization without any problems.

In the View:

<% Html.BeginForm("MyAction", "MyController", FormMethod.Post); %>
<button name="button" value="send"><%: Resources.Messages.Send %></button>
<button name="button" value="cancel"><%: Resources.Messages.Cancel %></button>
<% Html.EndForm(); %>

In the Controller:

public class MyController : Controller 
{
    public ActionResult MyAction(string button)
    {
         switch(button)
         {
             case "send":
                 this.DoSend();
                 break;
             case "cancel":
                 this.DoCancel();
                 break;
         }
    }
}

Answer 4

Here is a mostly clean attribute-based solution to the multiple submit button issue based heavily on the post and comments from Maartin Balliauw.

[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public class MultipleButtonAttribute : ActionNameSelectorAttribute
{
    public string Name { get; set; }
    public string Argument { get; set; }

    public override bool IsValidName(ControllerContext controllerContext, string actionName, MethodInfo methodInfo)
    {
        var isValidName = false;
        var keyValue = string.Format("{0}:{1}", Name, Argument);
        var value = controllerContext.Controller.ValueProvider.GetValue(keyValue);

        if (value != null)
        {
            controllerContext.Controller.ControllerContext.RouteData.Values[Name] = Argument;
            isValidName = true;
        }

        return isValidName;
    }
}

razor:

<form action="" method="post">
 <input type="submit" value="Save" name="action:Save" />
 <input type="submit" value="Cancel" name="action:Cancel" />
</form>

and controller:

[HttpPost]
[MultipleButton(Name = "action", Argument = "Save")]
public ActionResult Save(MessageModel mm) { ... }

[HttpPost]
[MultipleButton(Name = "action", Argument = "Cancel")]
public ActionResult Cancel(MessageModel mm) { ... }

Update: Razor pages looks to provide the same functionality out of the box. For new development, it may be preferable.

Answer 5

Give your submit buttons a name, and then inspect the submitted value in your controller method:

<% Html.BeginForm("MyAction", "MyController", FormMethod.Post); %>
<input type="submit" name="submitButton" value="Send" />
<input type="submit" name="submitButton" value="Cancel" />
<% Html.EndForm(); %>

posting to

public class MyController : Controller {
    public ActionResult MyAction(string submitButton) {
        switch(submitButton) {
            case "Send":
                // delegate sending to another controller action
                return(Send());
            case "Cancel":
                // call another action to perform the cancellation
                return(Cancel());
            default:
                // If they've submitted the form without a submitButton, 
                // just return the view again.
                return(View());
        }
    }

    private ActionResult Cancel() {
        // process the cancellation request here.
        return(View("Cancelled"));
    }

    private ActionResult Send() {
        // perform the actual send operation here.
        return(View("SendConfirmed"));
    }

}

EDIT:

To extend this approach to work with localized sites, isolate your messages somewhere else (e.g. compiling a resource file to a strongly-typed resource class)

Then modify the code so it works like:

<% Html.BeginForm("MyAction", "MyController", FormMethod.Post); %>
<input type="submit" name="submitButton" value="<%= Html.Encode(Resources.Messages.Send)%>" />
<input type="submit" name="submitButton" value="<%=Html.Encode(Resources.Messages.Cancel)%>" />
<% Html.EndForm(); %>

and your controller should look like this:

// Note that the localized resources aren't constants, so 
// we can't use a switch statement.

if (submitButton == Resources.Messages.Send) { 
    // delegate sending to another controller action
    return(Send());

} else if (submitButton == Resources.Messages.Cancel) {
     // call another action to perform the cancellation
     return(Cancel());
}

Answer 6

I've came across this 'problem' as well but found a rather logical solution by adding the name attribute. I couldn't recall having this problem in other languages.

http://www.w3.org/TR/html401/interact/forms.html#h-17.13.2

• ...
• If a form contains more than one submit button, only the activated submit button is successful.
• ...

Meaning the following code value attributes can be changed, localized, internationalized without the need for extra code checking strongly-typed resources files or constants.

<% Html.BeginForm("MyAction", "MyController", FormMethod.Post); %>
<input type="submit" name="send" value="Send" />
<input type="submit" name="cancel" value="Cancel" />
<input type="submit" name="draft" value="Save as draft" />
<% Html.EndForm(); %>`

On the receiving end you would only need to check if any of your known submit types isn't null

public ActionResult YourAction(YourModel model) {

    if(Request["send"] != null) {

        // we got a send

    }else if(Request["cancel"]) {

        // we got a cancel, but would you really want to post data for this?

    }else if(Request["draft"]) {

        // we got a draft

    }

}