Ajax.BeginForm with 4 arguments not finding the action method

Question

I have a weird case and I wanted your enlightenment. I have two controllers. One Person Controller for general Person use action methods and one Candidate Controller for more specific action methods related to Candidate. I use one partial view that is located under the Person folder in order to be used as generic in case I want to use it in the future for other types of Person. For the time being this partial view uses an Ajax.BeginForm targeting the Candidate Controller. The syntax I am using is

@using (Ajax.BeginForm("SaveCandidateLanguage", "Candidate",
    new AjaxOptions
    {
        HttpMethod = "Post",
        OnBegin = "onBeginFormValidation",
        OnSuccess = "onSaveCandidateLanguageSuccess"
    }))
{
    // form input elements
}

This type of Ajax.BeginForm works correctly despite of the fact that it targets an action in a different controller. Now for my form validation I had to put some more arguments to my Ajax.BeginForm. My new syntax is like that:

@using (Ajax.BeginForm("SaveCandidateLanguage", "Candidate",
    new AjaxOptions
    {
        HttpMethod = "Post",
        OnBegin = "onBeginFormValidation",
        OnSuccess = "onSaveCandidateLanguageSuccess"
    },
    new
    {
        id = "addEditCandidateLanguageForm",
        novalidate = "novalidate"
    }))
{
   // form input elements
}

For some reason this way can't find the Action method. If I put my action inside the Person Controller it works correctly again. However I was wondering why is that case. I did some digging but I didn't manage to get an answer about that.

From firebug I see that the url the browser tries to post is for some reason

http://{ProjectName}/Person/SaveCandidateLanguage?Length=9

instead of

http://{ProjectName}/Candidate/SaveCandidateLanguage?Length=9

and naturally I get a 404 Not found response. I was also wondering what is the variable ?Length=9 that I see at the end of the url and where does it come from.

Answer 1

Ajax.BeginForm has 11 differents declarations. In your first case, it works because you use this one :

Ajax.BeginForm(string actionName, string controllerName, AjaxOptions options)

But the second case you use this one, trying to put a string in the object routeValues parameter :

Ajax.BeginForm(string actionName, object routeValues, AjaxOptions options, object htmlAttributes)

Finally, the declaration you want to use is :

Ajax.BeginForm(string actionName, string controllerName, object routeValues, AjaxOptions ajaxOptions, object htmlAttributes)

implemented with a null value, like :

Ajax.BeginForm("SaveCandidateLanguage", "Candidate", null,
new AjaxOptions
{
    HttpMethod = "Post",
    OnBegin = "onBeginFormValidation",
    OnSuccess = "onSaveCandidateLanguageSuccess"
},
new
{
    id = "addEditCandidateLanguageForm",
    novalidate = "novalidate"
}))

And the reason for ?length="9" is because "Candidate" contains 9 characters and length is the only property of string