jquery ajax forms for ASP.NET MVC 3

this might be an easy question but for me right now it is not clear and I have to get things sorted in my head... maybe somebody can help me with that =)...

I know that MVC comes with Ajax Helpers. I know there is Microsoft library and there is also jquery. I know that with MVC 3 they introduced unobtrusive javascript which adds some special tags to html for cleannes...

but how does ist play together?

Example: I want to post a remote form (partial view) per ajax to add comments to a blog post. without posting the whole page back.

in my Partial View would I use Ajax.BeginForm() is this then MvcAjax or Jquery? Or would I use Html.BeginForm() and register something lik开发者_StackOverflow中文版e $.post on the click event of the Form. This would also have a fallback of plain html if javascript is disabled or not supported....

Or in general when to use what for posting comments to a blog post?... and I assume that it is correct, that I am posting to the create action of the commentscontroller and I would use the JsonModelBinder to transform it to a model. After that I would return Json and would append it to my comments list...

Is this reasonable why of doing it?

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Ajax.BeginForm() is this then MvcAjax or Jquery?

By default it is jquery. You need to reference the jquery.unobtrusive-ajax.js script for this to work.

Or would I use Html.BeginForm() and register something like $.post on the click event of the Form.

That's an alternative. Personally that's what I do.

I assume that it is correct, that I am posting to the create action of the commentscontroller and I would use the JsonModelBinder to transform it to a model. After that I would return Json and would append it to my comments list...

The JsonModelBinder has been introduced in ASP.NET MVC 3 and it allows you to send a JSON string to a controller action which will be mapped back to a view model. For example if you have the following view model:

public class PersonViewModel
{
    public string Name { get; set; }
    public int Age { get; set; }
}

and the following action:

public ActionResult Foo(PersonViewModel person) 
{
    ...    
}

the traditional way to invoke it in AJAX is:

$.ajax({
    url: '@Url.Action("foo")',
    type: 'POST',
    data: { name: 'john', age: 20 },
    success: function(result) {
        // TODO:
    }
});

and in ASP.NET MVC 3 you could send a JSON as request parameter which will be bound to the PersonViewModel action parameter:

$.ajax({
    url: '@Url.Action("foo")',
    type: 'POST',
    contentType: 'application/json',
    data: JSON.stringify({ name: 'john', age: 20 }),
    success: function(result) {
        // TODO:
    }
});