Insert object at database linked to existing object

Question

I have an object called "Professional", my professional has a list of "Skills"

I'm getting a problem when I try to insert a new skill to determinated professional

I've tried to do this at view that posts the new object:

<div>
    @Html.ActionLink("Add Skill", "AddNewSkill", new { skill = Model, id = ViewBag.professionalId} ) 
</div>

The controller methods

        public ActionResult AddNewSkill(int professionalId)
        {
            ViewBag.professionalId = professionalId;

            return View();
        }

        [HttpPost]
        public ActionResult AddNewSkill(SkillModel skill, int professionalId)
        {
            professionalBusiness = new ProfessionalBusiness();

            var professional = professionalBusiness.GetById(professionalId);
            professional.Skills.Add(skill);

            if (ModelState.IsValid)
            {
                professionalBusiness.Update(professional);
                return RedirectToAction("Index");
            }

            return RedirectToAction("Edit", professionalId);

        }

But that's wierd because my URL shows me only one parameter

http:// localhost:20995/Professional/AddNewSkill/1

And when I try to POST it gives me this error:

[ArgumentException: The parameters dictionary contains a null entry for parameter 'professionalId' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.ActionResult AddNewSkill(Int32)' in 'TCCApplication.Controllers.ProfessionalController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.
Nome do parâmetro: parameters]
   System.Web.Mvc.ActionDescriptor.ExtractParameterFromDictionary(ParameterInfo parameterInfo, IDictionary`2 parameters, MethodInfo methodInfo) +607955
   System.Web.Mvc.<>c__DisplayClass1.<Execute>b__0(ParameterInfo parameterInfo) +18
   System.Linq.WhereSelectArrayIterator`2.MoveNext() +66
   System.Linq.Buffer`1..ctor(IEnumerable`1 source) +216
   System.Linq.Enumerable.ToArray(IEnumerable`1 source) +77
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +135
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
   System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +28
   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +10
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +48
   System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +57
   System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +223
   System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +48
   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +24
   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +102
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +43
   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +14
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +57
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +47
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +47
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9690164
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

Answer 1

Your parameter names do not match between the call and the controller action.

Try changing the call to:

@Html.ActionLink("Add Skill", "AddNewSkill", new { skill = Model, professionalId = ViewBag.professionalId} )

EDIT:

POSTing your form data to your controller action is not easily possible with @Html.ActionLink() I would recommend that you wrap your existing view html in a BeginForm statement with a standard html submit button:

@using(Html.BeginForm("AddNewSkill","YourControllerName", FormMethod.Post))
{
    // ...your existing markup with the properties of the model here...
    <button type="submit">Add Skill</button>
}

This should post all of your model properties to your controller action. You should note that the various properties will get 'reassembled' (technically: bound) to the model on the server-side by the MVC ModelBinder.

IOW You don't need to try to send the model as a complete object, like you seemed to be trying to do with the RouteValues -- as in

new { skill = Model....

Hope that helps.

Answer 2

Where is your Id that mentioned on over the ActionLink

@Html.ActionLink("Add Skill", "AddNewSkill", new { skill = Model, id = ViewBag.professionalId} ) 

parameters name should match with the action result parameters. so change your action link as following

@Html.ActionLink("Add Skill", "AddNewSkill", new { skill = Model, professionalId = ViewBag.professionalId} ) 

this should work

cheers