I am using Mvc 3 and have come across the following scenario:
I've got a view model that has a list of note elemements as a property and I am using the HtmlHelper extension method EditorFor to render out the collection. All is working great. However now I need to display the note elements in the reverse order.
Is there a way to tell Mvc to reverse the elements?
// View Models
public class MyViewModel
{
public List<Note> Notes
{
get;
set;
}
}
public class Note
{
public string Username
{
get;
set;
}
public DateTime ChangedDate
{
get;
set;
}
public string Text
{
get;
set;
}
}
The elements are in oldest first order.
I can reverse the order of the elements in the collection to solve the problem which at the moments seems the most logically way to go. However that makes the javascript to insert new notes more complex as that requires the name and id of the html elements to be rewritten.
So I was hoping there maybe some sort of order option for the EditorFor method.
Another alternate would be to write a custom partial view and update the TemplateInfo.HtmlFieldPrefix but I like to keep to using the EditorTemplates if I can.
Related
I have two database classes as defined below:
public class TopDate
{
[Key]
public int DateId { get; set; }
public DateTime Date { get; set; }
}
public class TopSong
{
[Key]
public int SongId { get; set; }
public string Title { get; set; }
public int DateId { get; set; }
}
where DateId is foreign key to TopSong
I am creating a controller through which i can create, delete or edit these database values.
When i right click on controller class and add controller i can only select one of the two classes defined above. Is there a way to make 1 controller to handle database updates to both these tables on one page?
Error Image:
Your controller should not be dealing directly with domain objects (meaning those things that are directly associated with your database). Create a ViewModel that contains the properties that you need, use your service layer to populate the ViewModel and your controller will use that as the Model for its base. An example of your ViewModel could be something like the following given your description above:
public class MusicViewModel
{
public int SongId {get;set;}
public string Title {get;set;}
public IEnumerable<DateTime> TopDates {get;set;}
}
This view model would contain a list of all dates that a specific song was a Top Song.
The objects you showing (code) are database classes (so called domain objects).
What you need to do is to define a view model, a standard ASP MVC practice:
you define a class, that is tailored for specific view and only containing data relevant to that particular view. So you will have a view model for a view that will create a song, another that will update it etc.
Actually situation you describing is classical situation to use view models. Using domain objects in the views, however, is really really bad practice and prone to more problems than you want to deal with.
Hope this helps.
In building an app, we created a generic object model to store some values, the viewmodel looks a bit like this at the moment:
public class FooViewModel {
public int ID { get; set; }
public byte FooType { get; set; }
[Required]
[Display(Name = "Bar Name")]
public string Name { get; set; }
[Required]
public string Email { get; set; }
//etc, etc
}
The problem is: depending on the FooType, we want to have the Display Name to be different and the Email is not required for type 1 and 2, but is required for type 3 and 4.
We tried seperating out the properties that differ per type in to classes that inherit from this one, but the validation does a fallback on what is specified in the base type, so that didn't work.
Currently, the only option seems to be to create a viewmodel for each FooType (and also seperate controllers and view), which leads to a lot of code duplication.
What are other ways to keep this DRY?
To benefit a validation context (e.g. validating objects in different contexts), I strongly recommend using FluentValidation library.
You could implement a custom RequiredIf validation attribute, or you could implement IValidatableObject.
I want to create a form for an entity. One of the members is an IEnumerable of a different type (that also has an IEnumerable member), for example:
public class Person
{
public string Fullname { get; set; }
public int Age { get; set; }
public IEnumerable<Position> Jobs { get; set; }
}
public class Position
{
public string Title { get; set; }
public IEnumerable<string> PhoneNumbers { get; set; }
}
I'm trying to find a good example of creating multiple fields in the html, how would I allow to enter more than one position? I think I read somewhere about someone who's cloning that part of the form with jQuery - is that the way to go?
Thanks
This blog post talks about editing a variable length list and may be what you are after.
Possible duplicate of Editing a Variable Length List, ASP.NET MVC 3 Style with Table
I personnally use an improved version of BeginCollectionItem, but I find it still too complicated when used with child views.
This is a great fail of ASP.NET MVC promises (it should be simple, fluid and powerful).
I have a ViewModel that has been deserialized from JSON which looks something like this:
public class UserThingsUpdateViewModel
{
public IList<Thing> Things { get; set; }
[Required]
public int UserId { get; set; }
public int Age { get; set; }
}
Thing is also a ViewModel which also has various DataAnnotaion ValidationAttribute attributes on the properties.
The problem is that Lists don't seem to get validated and even after a through search I cant seem to find any articles that tackle this. Most suggest that the ViewModel is wrong if it includes a list.
So, what is the best way to validate my list and add Model Errors to the Model State?
Prior to checking ModelState.IsValid, you could add code to step through and validate each Thing, as follows:
foreach (var thing in Things)
TryValidateModel(thing);
This will validate each item, and add any errors to ModelState.
You could write a custom validator attribute and decorate the list property with it? That would allow you to write custom logic to get the elements out of the list and validate them.
I'm working on an ASP.NET MVC app (using MVC3 RC2). Say I have 2 entities, Product and Category. A Category must have a CategoryTitle, which is denoted via metamodel attributes like so:
public class CategoryModel
{
public int CategoryID { get; set; }
[Required("{0} is required.")]
public int CategoryTitle { get; set; }
}
There is also a relationship such that each Product has an association with Category. When searching Products, users must be able to filter the results by selecting a Category from a drop-down HTML select list. I've tried different ways of doing this, and the following seems to promote the most code reuse:
public class SearchModel
{
public CategoryModel Category { get; set; }
public string Keyword { get; set; }
}
public class ProductController
{
public ActionResult Search(SearchModel searchModel)
{
if (ModelState.IsValid)
{
// logic to return view with viewmodel
}
return HttpNotFound();
}
}
In the view, a drop-down list is rendered using the SearchModel, and it sends requests via HTTP GET in the form of /Product/Search?Keyword=my+keywords&Category.CategoryID=69. The SearchModel object is populated as intended, creating a new CategoryModel with CategoryID == 69.
The problem is that the ModelState.IsValid always returns false, since the Category.Title is null. What is the appropriate way to do this in ASP.NET MVC? Do I have to resort to creating a different SearchModel that doesn't have a CategoryModel instance?
The proper way to do this is to use view models instead of your models to and from the views. View models are classes which are specifically tailored to the needs of a given view: they contain only the properties required for the view and the validation attributes in the context of the given view. Thus you might have multiple view models for the same model. To map between the model and the view models you could use AutoMapper.