500（内部服务器错误）ASP.Net MVC 5 c＃

Question

I keep getting the error 500 (Internal Server Error) when I'm trying to save an object. I can't seem to find any way to even check what the exact error might be.

I'm trying to save an object through an API controller and then return the object when complete. I can return a string and the error goes away, which I'm sure I could figure out a way to make that work for me, but that just seems like a dirty way to fix a simple issue.

The object saves just fine, it just keeps throwing that error after it runs through my controller.

This is my API call:

self.postCategory = function (data) {
return $.ajax({
    url: '/API/Category/',
    type: 'POST',
    dataType: 'json',
    data: ko.toJSON(data),
    contentType: 'application/json; charset=urf-8',
    success: function (data) {
        self.getAlert('sucessfully saved category', 1);
        self.Category(data);
    },
    error: function (error) {
        self.getAlert(error, 4);
    }
});
}

This is the controller to handle the call:

public Category Post([FromBody]Category category)
{
using (MyContainer db = new MyContainer())
{
    if (db.Categories.Where(n => n.Id == category.Id).Any())
    {
        db.Categories.Attach(category);
        db.Entry<Category>(category).State = EntityState.Modified;
    }
    else
    {
        db.Categories.Add(category);
    }
    try
    {
        db.SaveChanges();
        return category;
    }
    catch (Exception e)
    {
        Elmah.ErrorSignal.FromCurrentContext().Raise(e);
        return new Category();
    }
}
}

This seems to only happen to categories with records related to it in a one-to-many relationship. New categories or updates to categories without related records do not have the same issue.

It just doesn't make sense to me anymore.

Any help would be greatly appreciated!

Thank you!

Answer 1

The problem was with my knockout binding.

This:

function CategoryModel(data) {
    var self = this;

    self.Id = data.Id;
    self.Name = ko.observable(data.Name);

    self.Products = ko.observableArray([]);
}

Should have been this:

function CategoryModel(data) {
    var self = this;

    self.Id = data.Id;
    self.Name = ko.observable(data.Name);

    self.ProductModels = ko.observableArray([]);
}

In my .edmx I was naming the associations between my entities as Products and Category by default. Then when I made the call it would send the category with the products, make the update to the category, then return the category with complex objects. Which is bad for webapi, and hence the 500 error.

Solution: Name your observableArray literally ANYTHING other than the same name as the association.

Thanks for the help!