剃刀：处理视图中的对象列表以及模型验证

Question

I have two classes like this (to make it simple)

public class Page
{
    int pageNumber;
    string content;
}

public class Book
{
    public string name;
    public List<Page> pages;
}

Now, in a razor view, I have a form allowing to add a book, with a list of pages in the form, to add pages.

Currently, the pages are added dynamically to the form, and I get the values in my controller using Request.Form for building my list of Pages in the controller. The problem is, how can I validate the model with the pages (something like a page must have a content not empty for example) before entering in the action in the controller.

The fields are added with JQuery in the form. I think it not possible to bind a list of Pages directly to the model in the view, especially when the fields are generated with javascript. But maybe I am missing something.

Thanks

Answer 1

you can validate the pages in JQuery before the data is send to the server.

or you can user a filter. a filter is a method that is executed before an action is executed. (you may have seen or used the [Authorize] filter)

you can create a filter that validates the data and if the validation fails the request will be redirected to an error page.

here is a tutorial

here is another tutorial

Answer 2

You can use model binding in ASP.NET, even if you're adding jquery form elements, see this to create collections that are binding to model:

ASP.NET Wire Format for Model Binding to Arrays, Lists, Collections, Dictionaries

I think your form can be done as that in order to run model binding correctly:

<input type="text" name="name"/>
<input type="text" name="pages[0].pageNumber"/>
<input type="text" name="pages[0].content" />
<input type="text" name="pages[1].pageNumber"/>
<input type="text" name="pages[1].content"/>
<input type="text" name="pages[3].pageNumber"/>
<input type="text" name="pages[3].content"/>

With that use, you can receive the Book object from the view to your controller:

public ActionResult Create(Book myBook)
    {}

Then, for validation, I suggest you tu use Data Annotation to your model, use [Required] tag before the content property of page object, or [MinLenght], see this Microsoft documentation about Data Annotations.

[Required]
public string Content { get; set; }

Then in your view, use jquery.validate (don't forget to enable it in the view) and in the controller, when you receive your model, you can check the modelstate with

public ActionResult Create(YourObject object)
{
    if (ModelState.IsValid)
    {
            // code when model is valid
    }
}

Answer 3

With MVC you can use DataAnnotations on your model properties.

Using using System.ComponentModel.DataAnnotations;

public class Book{

    [Required]
    public string Name{ get; set; }

    public List<Page> Pages { get; set; }
}

public class Page{

    [Required]
    public int PageNumber{ get; set; }

    [Required]
    public string Content { get; set; }
}

For a deeper understanding read this: http://www.asp.net/mvc/overview/older-versions/getting-started-with-aspnet-mvc4/adding-validation-to-the-model