Model binding in ASP.NET MVC when editing an entity - asp.net-mvc

i am kind of stuck with this code:
[AcceptVerbs(HttpVerbs.Post), Authorize]
public ActionResult Edit(FormCollection collection, [Bind(Exclude="Id,Latitude,Longitude")]Store bindStore, string Latitude, string Longitude)
{
Store st = storeModel.GetStore(Session["user_id"].ToString());
bool modelUpdate = TryUpdateModel(st, new string[] { "Storename", "Address1", "Address2", "Zipcode", "City", "Phone1", "Phone2", "Store_email", "Store_homepage", "Pm_ec", "Pm_visa", "Pm_master", "Appointment_requirement", "Short_user_store_description" });
if (ModelState.IsValid)
{
storeModel.Save();
return RedirectToAction("ImageUpload");
}
else
return Edit();
}
My problem is, that i don't know whats the right way to do the ModelBinding, when i need these conditions to match:
The "Store" object has several fields ( not only Id ) that should NOT be updated during this update ( had problems that the "TryUpdateModel" NULL-ifies all these fields, so i added the "includeProperties" value with the cleartext of all the params.. a solution i don't like anyway)
Getting the store id from session as i don't want it to be in the HTML
Making InputValidation through the DataAnnotationModel ( see below )
[MetadataType(typeof(StoreMetaData))]
public partial class Store
{
}
public class StoreMetaData
{
[Required]
[StringLength(5)]
public object Storename { get; set; }
}
Question: Is this the right approach or is there a standard/nicer solution for this kind of problem?

You don't need formcollection in parameters for start.
And no, updatemodel will try to update all fields of model if no white or black list defined.
So either that or create your own function to update your model objects.
Maybe somethig generic. that will reflection enumerate properties of supplied update object and apply those that are not null to object being updated.

My guess, from looking at the code you posted, is that you're trying to make it so that the Edit view will only allow certain fields to be edited, but 'pass through' the ones you don't want changed. In that case, you can modify your Edit view to remove those fields from being edited, but still send them over in the form using:
<%= Html.Hidden("field") %>
Let me know if this is what you intended.

Your way is fine IMHO.
There are other options but none of them provide a compelling benefit over your technique.
The only thing I would do differently is to model bind to custom ViewModel with the exact fields you need and then do the rightly-lefty code to assign just those values:
public ActionResult Edit( SlimStoreViewmodel editStoreModel, string Latitude, string Longitude)
{
Store st = storeModel.GetStore(Session["user_id"].ToString());
if (ModelState.IsValid)
{
st.Thing = editStoreModel.Thing;
st.Thing2 = editStoreModel.Thing2;
st.Widget = editStoreMOdel.Widget;
storeModel.Save();
return RedirectToAction("ImageUpload");
}
else
return Edit();
}
This gets rid of long magic string dense things like this:
TryUpdateModel(st, new string[] { "Storename", "Address1", "Address2", "Zipcode", "City", "Phone1", "Phone2", "Store_email", "Store_homepage", "Pm_ec", "Pm_visa", "Pm_master", "Appointment_requirement", "Short_user_store_description" });

Related

Edit operation not saving to the DB

I posted the question earlier, but didn't receive any correct responses, hence posting again with some edits. I have a function that accepts two parameters, IDs and Dates. When I had put breakpoints, I was able to see the Ids and the Dates selected on the page as parameter values. However, after hitting the process button, nothing happens, meaning this data isn't getting saved to the DB.
Model Classes:
public class Hello{
public string ID{ get; set; }
[DataType(DataType.Date)]
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
public DateTime? Date{ get; set; }
}
Controller Class:
[HttpGet]
public ActionResult Selection(string ids, string dates)
{
model = new Hello();
ExtensionDB db = new ExtensionDB();
string[] IDS = ids.Split(',');
string[] DATES = dates.Split(',');
List<Hello> list = new List<Hello>();
for (int i = 0; i < IDS.Length; i++)
{
if (IDS[i] != null && IDS[i] != "")
{
Hello item = new Hello { ID = IDS[i], Date = DateTime.Parse(DATES[i]) };
list.Add(item);
}
}
if (ModelState.IsValid)
{
foreach (var row in db.Table1)
{
foreach (var row2 in db.Table2)
{
if (row.UID== row2.CID) // UID and CID are Foreign keys that join these two tables
{
foreach (var item in list)
{
if (row.UID == Convert.ToInt32(item.ID))
{
row2.ReportedDate = item.Date;
}
db.SaveChanges();
}
}
}
}
ViewBag.Message = "Success";
return View(model);
}
else
{
ViewBag.Message = "Failed";
return View(model);
}
}
I will add the view class if needed, however the problem is here.. You can also refer to it here: Saving changes to the DB MVC
Your code does not attempt to update anything. Start with confirming what the data you are passing to this POST call contains, and what you want to do with it. It looks like what you are trying to do is update the dates for a number of records. Looking at your previous post (no need to re-post another question with the same code) there are a few things..
First: Structure the data you want to pass to the POST call into a collection of simple objects containing an id and a date. For example:
{
id = rid,
date = date
}
and add those to the collection named something like "updateData" rather than two separate arrays of IDs and dates. Then in the server-side code, declare a simple view model class:
public class UpdateDateViewModel
{
public int Id { get; set; }
public DateTime Date { get; set; }
}
In the ajax call instead of:
data: { ids: ids, dates: dates },
you'll want something like:
data: { updates: updateData },
where updateData is your collection of id + date pairs.
and use that view model in your method:
public ActionResult Process(IList updates)
Provided that request data is sent as Json, ASP.Net should translate that data automatically for you, though you may need to configure ASP.Net to translate the camelCase vs PascalCase. Worst case, to test, you can use camelCase property names ("id" and "date")
Now when it comes to updating the data: Server side, please get in the habit of using meaningful variable names, not "c", "i", etc. It makes code a lot easier to understand.
public ActionResult Process(IList<UpdateDateViewModel> updates)
{
using (db = new DB())
{
//rp = new RequestProcess(); - Assuming RequestProcess is an Entity?
//var c = rp.getStuff(); - No idea what this getStuff() method does...
foreach(var update in updates)
{
var request = db.RequestProcesses.Find(update.Id);
if (request != null)
request.RequestDate = update.Date; // If we find a matching request, update it's date.
else
{ // Doesn't exist, create it and add it to the DbSet.(table)
var request = new RequestProcess { Id = update.Id, RequestDate = update.Date };
db.RequestProcesses.Add(request);
}
db.SaveChanges();
}
}
}
Now this is a very bare bones guess at what you may be trying to do. Ideally though, updates should be completely separate from adds in the sense that an update should only deal with existing records. If it comes across an ID that it cannot find it should throw an error, ignore, and/or return a status to the user that something wasn't right. Creating new entries should be a separate call and ensure that records are properly initialized with their required fields.
Your original code looked to be taking a list of IDs, but then creating a new entity and calling that "getStuff" method that didn't have the DbContext, or any of the values from the POST call, but then attempting to copy values from that entity into the string parameters that you passed (which would overwrite the Json string) None of that would have updated an entity which would never have updated your data.
Take it slow and follow the examples before attempting to adapt them to your ideas. It will be a lot more constructive and less frustrating then writing a bunch of code that doesn't really make much sense, then wondering why it doesn't work. Your original code has probably a dozen or more problems and inefficiencies. Simply pasting it up on Stack will get a lot of confusing comments based on these problems which don't really help with the first issue you want to solve. Strip it back to the minimum, start with getting the data you need to the server in a meaningful way, then from that, attempt to use that data to update your entities.

Is there a way to change column name before fetching data?

Is there a way to change column name before fetching data in all the controllers I call that column from, for example I had 2 columns in my table "Section" : "Title" and "TitleEN"
If the current culture is "en", I want to fetch "TitleEn" data but in my code I'll only use "Title" like this:
section.Where(p =>
p.Title.ToUpper().Contains(searchword.ToUpper()));
I was working on a project with only one language and then the client requested adding English. Unfortunately I made the wrong decision by adding language fields for every table having string fields.
Now I want to fix this because the project has a lot of code dealing only with fields without "En".
I'm not entirely sure on how this is being called, but you could be a bit sneaky on the entity itself. I think you are saying that you are always using the Title property on the entity, but you need it to be EN when the culture is set to EN. If you don't mind selecting both values every time on every query, there is an easy fix for this.
In your entity, I would do something like this:
public class MyEntity
{
[Column("Title")] // Can use FluentApi here instead
public string TitleOld { get; set; }
[Column("TitleEN")]
public string TitleEN { get; set; }
[NotMapped]
public string Title
{
get { return Thread.CurrentThread.CurrentUICulture.Name == "en-US" ? TitleEN : TitleOld; }
set { TitleOld = value; }
}
}
This way, your code wouldn't change, but you'd be selecting both values down every time.
not the best solution, but you can just use an If currentcul is En, then
section.Where(p =>
p.TitleEN.ToUpper().Contains(searchword.ToUpper()));
Else{
section.Where(p =>
p.Title.ToUpper().Contains(searchword.ToUpper()));
}
I would recommend using a diffrent solution tho.
I hope this will work
var section = new List<Test>();
var result = section.Where(x => (System.Globalization.CultureInfo.CurrentCulture.Name.Equals("en")
&& x.TitleEn.ToUpper().Contains(searchword.ToUpper()))
|| (!System.Globalization.CultureInfo.CurrentCulture.Name.Equals("en")
&& x.Title.ToUpper().Contains(searchword.ToUpper())));

Want to save selected (i.e., more than 1) enums as string with NHibernate

I cannot for the life of me get this to work with my existing code, but I am trying to save my enum selections as strings in NHibernate. Basically, I have a UI check box and if the user selects multiple check boxes I want to store those selections. Now, I can get NHibernate to store ONE selection (e.g., from a drop down or radio button list, where the user is limited to one choice only).
This is the jist of what I have for an enum:
public enum IncomeType
{
[Display(Name = "Full-Time Employment")]
FullTime,
[Display(Name = "Part-Time Employment")]
PartTime,
[Display(Name = "Self-Employment")]
SelfEmployed,
[Display(Name = "Rental")]
Rental,
[Display(Name = "Social Security Payments")]
SocialSecurity,
[Display(Name = "Retirement / Pension Payments")]
Retirement,
[Display(Name = "Child Support Payments")]
ChildSupport,
[Display(Name = "Spousal Maintenance")]
Maintenance,
[Display(Name = "Other")]
Other
}
I use a method to "select" whether a checkbox list is shown (if my BulkItemThreshold equals the number of options, a checkbox list is displayed). Here is that method:
public static IEnumerable<SelectListItem> GetItemsFromEnumString<T>
(T selectedValue = default(T)) where T : struct
{
return from name in Enum.GetNames(typeof(T))
let enumValue = Convert.ToString((T)Enum.Parse(typeof(T), name, true))
select new SelectListItem
{
Text = GetEnumDescription(name, typeof(T)),
Value = enumValue,
Selected = enumValue.Equals(selectedValue)
};
}
(Note: some items in there are helpers, but I don't believe they are relevant; also, the selected input is displayed using a template .cshtml file - again, not sure if that's relevant)
Now, I call this thusly:
public class IncomeTypeSelectorAttribute : SelectorAttribute
{
public override IEnumerable<SelectListItem> GetItems()
{
return Selector.GetItemsFromEnumString<IncomeType>();
}
}
And finally, we get to the virtual property (using a proxy) but this is where NHibernate throws a wrench (Note: this was working fine for me before NHibernate, and now I am trying to get many lines of code working with it WITHOUT having to re-do everything; if I re-do everything I will probably triple the code I already have to get it to work):
Property (record):
[IncomeTypeSelector(BulkSelectionThreshold = 9)]
public virtual List<string> IndividualIncomeTypeCheckBox { get; set; }
proxy (part):
public List<string> IndividualIncomeTypeCheckBox
{
get { return Record.IndividualIncomeTypeCheckBox; }
set { Record.IndividualIncomeTypeCheckBox = value; }
}
Again, this is how I was doing things and it was working great before NHibernate. But now I have to use NHibernate. No getting around it.
I am using a service class that it tying the two together in a Create method to save in the DB with NHibernate, and for the above it would ordinarily look like this:
part.IndividualIncomeTypeCheckBox = record.IndividualIncomeTypeCheckBox;
This would work if it were just one selection.
Well, I've spent a good two (2) months trying to get this to work. It's tough because I have lots of code where the user can make only one selection (such as with a radiobutton list) and it works GREAT - even with NHibernate. Let me give you an example:
public virtual IncomeType? IndividualIncomeTypeCheckBox { get; set; }
If I do the above, it will display a drop down list, and NHibernate will store the ONE allowable option selected by the user in the DB no problem. But more than one option with List<string> does not work.
Now, I have tried everything I could find here or elsewhere and nothing works. Yes, I know it should be IList<IncomeType> or some other variant. But if I use this then NHibernate requires that IncomeType be another table in the DB. This is too much code to write for such a simple thing I believe. We are not talking a many-to-many relation in the sense that this is not a User with Multiple addresses (wherein addresses would have street, city, state, zip, etc.).
I have tried different types of proxy get and set code, but nothing works. I have tried [Flags] and other things working with string only, but to no avail. Those last solutions would "work" but ONLY to save the first item selected out of multiple (i.e., in my scenario, if the user selected "FullTime" and "Rental" as Income Types, then only "FullTime" (string) would be saved or "1" ([Flags]/int), not both items selected.
I have a situation where I re-display the choices using a ReadOnly attribute like this:
[IncomeTypeSelector]
[ReadOnly(true)]
public List<string> IndividualIncomeTypeCheckBoxPost
{
get { return IndividualIncomeTypeCheckBox; }
}
This would display on the UI, but I tried doing something like this with NHibernate and it wouldn't work.
Could anyone please show me, using the above, how I can go about getting NHibernate to store more than one enum in this checkbox list scenario?
UPDATE:
More poking around here and on the web, and I came up with the following (which still does not work).
Property (record):
[IncomeTypeSelector(BulkSelectionThreshold = 9)]
public virtual IList<IncomeTypeRecord> IndividualIncomeTypeCheckBox
{
get { return incomeType; }
set { incomeType= value; }
}
private IList<IncomeTypeRecord> incomeType =
new List<IncomeTypeRecord>();
Proxy (part):
public IList<IncomeTypeRecord> IndividualIncomeTypeCheckBox
{
get { return Record.IndividualIncomeTypeCheckBox; }
set { Record.IndividualIncomeTypeCheckBox= value; }
}
And a change to the enum:
public enum IncomeType : int // removing int & value still gives validate error
{
[Display(Name = "Full-Time Employment")]
FullTime = 1,
[Display(Name = "Part-Time Employment")]
PartTime,
....
}
And I added this class to support IncomeTypeRecord
public class IncomeTypeRecord
{
public virtual int Id { get; set; }
public virtual IncomeType Value { get; set; }
}
HOWEVER, when I get to the UI screen and pick one or more options I get a validation error (value not valid). For example, say I pick FullTime alone, or pick FullTime and Retirement, then the UI will display the following error:
The value 'FullTime' is invalid.
The value 'FullTime,Retirement' is invalid.
(respectively)
Even if I remove the int declaration for the enum and get rid of the value I started with "1", I still get this validation error. I tried messing around with and adding different model binders (which now has me stumped as to whether my original problem still exists and now I have a different problem - but you still get bounty points :) ).
Pulling my hair out. If I could offer more bounty I would. I need a definitive solution. I appreciate any help.
UPDATE
This is what I have so far:
Record:
public virtual string IndividualIncomeTypeCheckBox{ get; set; }
Part:
//If I do IEnumberable<string> my .Select throws a cast error
public IEnumerable<IncomeType> IndividualIncomeTypeCheckBox
{
get
{
return Record
.IndividualIncomeTypeCheckBox
.Split(',')
.Select(r => (IncomeType)Enum.Parse(typeof(IncomeType), r));
}
set { Record.IndividualIncomeTypeCheckBox= value
== null ? null : String.Join(",", value); }
}
Service Class:
public SimplePart CreateSimple(SimplePartRecord record)
{
SimplePart simple = Services.ContentManager.Create<SimplePart>("Simple");
...
//How I would save a FirstName property (example Part / PartRecord below)
//public virtual string FirstName { get; set; } - PartRecord
//public string FirstName - Part
//{
// get { return Record.FirstName ; }
// set { Record.FirstName= value; }
//}
simple.FirstName = record.FristName;
...
//I obviously cannot do the following with the above IncomeType
//Getting cannot convert string to IEnumerable error
//How would I write this:
simple.IndividualIncomeTypeCheckBox = record.IndividualIncomeTypeCheckBox;
...
}
And this is how it's called in a controller (this persists to DB): (Updating Controller code)
public ActionResult Confirm(string backButton, string nextButton)
{
if (backButton != null)
return RedirectToAction("WrapUp");
else if ((nextButton != null) && ModelState.IsValid)
{
_myService.CreateSimple(myData.SimplePartRecord);
return RedirectToAction("Submitted");
}
else
return View(myData);
}
Updating with additional code (serialization and view model):
"myData" is defined in the controller (using Serialization) as:
private MyViewModel myData;
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
var serialized = Request.Form["myData"];
if (serialized != null)
{
myData = (MyViewModel)new MvcSerializer().Deserialize
(serialized, SerializationMode.Signed);
TryUpdateModel(myData);
}
else
myData = (MyViewModel)TempData["myData"] ?? new MyViewModel();
TempData.Keep();
}
protected override void OnResultExecuted(ResultExecutedContext filterContext)
{
if (filterContext.Result is RedirectToRouteResult)
TempData["myData"] = myData;
}
I use Serialization because I set up a multi-step wizard (as seen in the controller action "backButton" "nextButton) on the front-end. I am not using a driver (which can only display Admin or on the front-end but then only on .cshtml files directly under the ~/Views folder (not in a structured folder list like I am using)). No driver = no update view model type code = no mechanism to "create" the data in the DB. If I do not use some "create" type method, the form will submit but all the data will be "NULL".
When you say that the data should be persisted automatically, I am sorry but I do not see how. All the stuff I read or code I review has SOME method of updating the DB with whatever is entered in a form. If I am missing something, my apologies.
"MyViewModel" is pretty straightforward:
[Serializabel]
public class MyViewModel
{
public SimplePartRecord SimplePartRecord { get; set; }
}
And, just in case, here is the relevant portion of the migration (return 1 is a completely separate and unrelated table):
public int UpdateFrom1()
{
SchemaBuilder.CreateTable("SimplePartRecord",
table => table
.ContentPartRecord()
...
.Column("IndividualIncomeTypeCheckBox", DbType.String)
...
);
ContentDefinitionManager.AlterPartDefinition("SimplePart",
part => part
.Attachable(false));
return 2;
}
The error I am getting is
Cannot implicitly convert type 'string' to 'System.Collections.Generic.IEnumerable'"
when I do the following in the "Create" method of my service class:
simple.IndividualIncomeTypeCheckBox = record.IndividualIncomeTypeCheckBox;
One additional thought: I tried using the n-n Relation sample to handle this scenario. Aside from it being a lot of extra code for what I thought should be straightforward and simple, because of the way I am using Serialization I had a lot of object reference errors and could not figure out how to properly code my controller to handle it.
There's a lot of info to wade through here so hopefully I haven't missed the point. It appears to me that the goals are:
The business class has a collection property of IList<IncomeType> without requiring an additional table
The values in that collection should be persisted as a delimited string of the enum names
The best approach is to use a custom user type (an implementation of NHibernate.UserTypes.IUserType) to map the property. Below is a generic IUserType that will map an enum of type T from an IList<T> property to a comma delimited string in the database and back again. There's no easy way to restrict T to an enum but the code will only work with enums.
Mapping a property using the custom type is simple with Fluent NHibernate:
public class Person
{
public Person()
{
IncomeTypes = new List<IncomeType>();
}
public virtual int PersonId { get; protected set; }
public virtual string FirstName { get; set; }
public virtual string LastName { get; set; }
public virtual IList<IncomeType> IncomeTypes { get; protected set; }
}
public class PersonMap : ClassMap<Person>
{
public PersonMap()
{
Table("Person");
Id(x => x.PersonId).GeneratedBy.Identity();
Map(x => x.FirstName);
Map(x => x.LastName);
Map(x => x.IncomeTypes).CustomType<EnumAsDelimitedStringType<IncomeType>>();
}
}
And here's the code for the user type:
public class EnumAsDelimitedStringType<T> : IUserType
{
public new bool Equals(object x, object y)
{
if (ReferenceEquals(x, y))
{
return true;
}
var xList = x as IList<T>;
var yList = y as IList<T>;
if (xList == null || yList == null)
{
return false;
}
// compare set contents
return xList.OrderBy(xValue => xValue).SequenceEqual(yList.OrderBy(yValue => yValue));
}
public int GetHashCode(object x)
{
return x.GetHashCode();
}
public object NullSafeGet(IDataReader rs, string[] names, object owner)
{
var outValue = NHibernateUtil.AnsiString.NullSafeGet(rs, names[0]) as string;
if (string.IsNullOrEmpty(outValue))
{
return new List<T>();
}
var getValueArray = outValue.Split(new[] {','}, StringSplitOptions.RemoveEmptyEntries);
return Array.ConvertAll(getValueArray, s => (T)Enum.Parse(typeof(T), s)).ToList();
}
public void NullSafeSet(IDbCommand cmd, object value, int index)
{
var inValue = value as IList<T>;
// set to string.Empty if you prefer to store that instead of null when the collection is null or empty
object setValue = null;
if (inValue != null && inValue.Any())
{
var setValueArray = Array.ConvertAll(inValue.ToArray(), v => Enum.GetName(typeof(T), v));
setValue = string.Join(",", setValueArray);
}
NHibernateUtil.AnsiString.NullSafeSet(cmd, setValue, index);
}
public object DeepCopy(object value)
{
return value;
}
public object Replace(object original, object target, object owner)
{
return original;
}
public object Assemble(object cached, object owner)
{
return cached;
}
public object Disassemble(object value)
{
return value;
}
public SqlType[] SqlTypes
{
get { return new[] {new SqlType(DbType.AnsiString)}; }
}
public Type ReturnedType
{
get { return typeof(IList<T>); }
}
public bool IsMutable
{
get { return false; }
}
}
I think you're on the right track pursuing a [Flags] enum. You may have done this, but just in case -- making an enum flags-worthy is more than adding the attribute. You also have to specify the value for the items in a binary-friendly manner. I've found the easiest way to do this is as follows:
[Flags]
public enum IncomeType : long // you'll need the room with several options
{
FullTime = 1,
PartTime = 1 << 1,
SelfEmployed = 1 << 2
// And so on
}
If you don't do this, then you'll get sequential integer values, which breaks the bitwise comparison that allows you to do multiple values in a single integer.
Your code to create the SelectList looks fine. Your options should construct form values that get posted back with the same name. If you want to use the default modelbinder, that means the associated property on your view model would need to be List<int>. If you're not using a view model (you probably should) you can pull it out of the forms collection.
Once you have this set up, then translating from your view model to your NHibernate entity is simple if a little annoying. You basically have to cycle through the values in the list and |= them onto your NHibernate entity's single enum property.
So let's assume you have a view model like this:
public class MyEditViewModel
{
public string Name { get; set; }
public List<int> IncomeSelections { get; set; }
// You'll probably have this to populate the initial view rendering
public SelectList AllIncomeOptions { get; set; }
}
You'll build your view using your helpers and all that, then build the checkboxes using the SelectList but making sure the input name is IncomeSelections, then when it's posted back you will push the view model data into your NHibernate entity something like this:
var myNHEntity = new NHEntity();
// If you're editing an existing entity, then be sure to reset the enum
// value to 0 before going into the following foreach loop...
foreach (var incomeSelection in viewModel.IncomeSelections)
{
myNHEntity.IncomeSelection |= incomeSelection;
}
There's probably a more clever way to do this, and you might have to cast the int to your enum type, but you'll figure that out (I'd do it for you, but it is Friday and I already have a beer open).
NHibernate should persist it without you having to do anything funky on the NH side.
In summary...
It seems like this is more a problem of how you handle the posted data than the NHibernate side. If you implement something like this, then be sure to use Fiddler or FireBug to inspect the posted values to make sure 1) they're integers and 2) the names are the same so they'll be added to the list.
Good luck!
The problem is simply that it won't be able to map a List without building a full relationship with an intermediate association table. It is way simpler to have the record store the values as a comma-separated string (so your record property is a string, not a list of string) and your part can map back and forth between string and List.
You can find an example of something very close here:
https://bitbucket.org/bleroy/nwazet.commerce/src/d722cbebea525203b22c445905c9f28d2af7db46/Models/ProductAttributesPartRecord.cs?at=default
https://bitbucket.org/bleroy/nwazet.commerce/src/d722cbebea525203b22c445905c9f28d2af7db46/Models/ProductAttributesPart.cs?at=default
It's not using enum values, instead it's a list of ids, but that should give you a good idea about how to make this work fairly simply: parsing enums you already know how to do.
Let me know if you need more details, but I think that's what you needed to get unblocked.

Entity Framework ASP.NET MVC private model fields

There is a field in our database which really ought to be a boolean, but for some reason the original developers made it a CHAR which will either be set to "1" or "0".
[Column("CHARGEABLE")]
[StringLength(1)]
private string Chargeable { get; set; }
I want my model to represent this field as a boolean so I figured I could add a property to my model to wrap it:
[NotMapped]
public bool ChargeableTrue
{
get
{
return Chargeable == "1" ? true : false;
}
set
{
Chargeable = value ? "1" : "0";
}
}
Now on my View I just display the EditorFor ( ChargeableTrue ), but when I click save it doesn't actually update it.
I think what is happening is that when the model is being updated, it's still attempting to get the value of 'Chargeable' from the View, even though I haven't displayed it there. And since there is no input field, it just gets null and ends up saving that to the database.
if (ModelState.IsValid)
{
db.Entry(call).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
What is one expected to do in this situation?
Based on KMan's answer, here's the extended version just in case you're not familiar with creating view models.
The idea is that your domain object is not really what you want to be updating exactly from your views. Instead, you create a go-between that can also include view-specific items (like a list of objects to populate a drop-down).
public class MyViewModel {
public bool Chargeable { get; set; }
}
Now you can do this:
#* In view *#
Html.EditorFor(m => m.Chargeable)
// In controller
public ActionResult Save(MyViewModel model) {
if (ModelState.IsValid) {
var domainObject = new MyObject() {
Chargeable = model.Chargeable ? "1" : "0"
};
// the rest of your code using domainObject
}
}
I'd consider just creating an overload of your domain object's constructor that accepts your view model to keep the mapping in one place. I typically use a tool like AutoMapper to map objects or manual extension methods.
A view model typically contains a sub-set of your domain object's properties, but can contain all of them or more properties like lists, visbility states, etc. They come in incredibly useful and I've never done a MVC project where I haven't used them.
Use a view model and make your mapping on the controller.

How do I populate a dropdownlist with enum values?

I have an enum for one of the properties of my view-model. I want to display a drop-down list that contains all the values of the enum. I can get this to work with the following code.
What I'm wondering is whether there is a simple way to convert from an enum to an IEnumerable? I can do it manually as in the following example, but when I add a new enum value the code breaks. I imagine that I can do it via reflection as per this example, but but are there other ways to do this?
public enum Currencies
{
CAD, USD, EUR
}
public ViewModel
{
[Required]
public Currencies SelectedCurrency {get; set;}
public SelectList Currencies
{
List<Currencies> c = new List<Currencies>();
c.Add(Currencies.CAD);
c.Add(Currencies.USD);
c.Add(Currencies.EUR);
return new SelectList(c);
}
}
I'm using a helper that i found here to populate my SelectLists with a generic enum type, i did a little modification to add the selected value though, here's how it looks like :
public static SelectList ToSelectList<T>(this T enumeration, string selected)
{
var source = Enum.GetValues(typeof(T));
var items = new Dictionary<object, string>();
var displayAttributeType = typeof(DisplayAttribute);
foreach (var value in source)
{
FieldInfo field = value.GetType().GetField(value.ToString());
DisplayAttribute attrs = (DisplayAttribute)field.
GetCustomAttributes(displayAttributeType, false).FirstOrDefault()
items.Add(value, attrs != null ? attrs.GetName() : value.ToString());
}
return new SelectList(items, "Key", "Value", selected);
}
The nice thing about it is that it reads the DisplayAttribute as the title rather than the enum name. (if your enums contain spaces or you need localization then it makes your life much easier)
So you will need to add the Display attirubete to your enums like this :
public enum User_Status
{
[Display(Name = "Waiting Activation")]
Pending, // User Account Is Pending. Can Login / Can't participate
[Display(Name = "Activated" )]
Active, // User Account Is Active. Can Logon
[Display(Name = "Disabled" )]
Disabled, // User Account Is Diabled. Can't Login
}
and this is how you use them in your views.
<%: Html.DropDownList("ChangeStatus" , ListExtensions.ToSelectList(Model.statusType, user.Status))%>
Model.statusType is just an enum object of type User_Status.
That's it , no more SelectLists in your ViewModels. In my example I'm refrencing an enum in my ViewModel but you can Refrence the enum type directly in your view though. I'm just doing it to make everything clean and nice.
Hope that was helpful.
Look at Enum.GetNames(typeof(Currencies))
I am very late on this one but I just found a really cool way to do this with one line of code, if you are happy to add the Unconstrained Melody NuGet package (a nice, small library from Jon Skeet).
This solution is better because:
It ensures (with generic type constraints) that the value really is an enum value (due to Unconstrained Melody)
It avoids unnecessary boxing (due to Unconstrained Melody)
It caches all the descriptions to avoid using reflection on every call (due to Unconstrained Melody)
It is less code than the other solutions!
So, here are the steps to get this working:
In Package Manager Console, "Install-Package UnconstrainedMelody"
Add a property on your model like so:
//Replace "YourEnum" with the type of your enum
public IEnumerable<SelectListItem> AllItems
{
get
{
return Enums.GetValues<YourEnum>().Select(enumValue => new SelectListItem { Value = enumValue.ToString(), Text = enumValue.GetDescription() });
}
}
Now that you have the List of SelectListItem exposed on your model, you can use the #Html.DropDownList or #Html.DropDownListFor using this property as the source.
So many good answers - I thought I'sd add my solution - I am building the SelectList in the view (and not in the Controller):
In my c#:
namespace ControlChart.Models
//My Enum
public enum FilterType {
[Display(Name = "Reportable")]
Reportable = 0,
[Display(Name = "Non-Reportable")]
NonReportable,
[Display(Name = "All")]
All };
//My model:
public class ChartModel {
[DisplayName("Filter")]
public FilterType Filter { get; set; }
}
In my cshtml:
#using System.ComponentModel.DataAnnotations
#using ControlChart.Models
#model ChartMode
#*..........*#
#Html.DropDownListFor(x => x.Filter,
from v in (ControlChart.Models.FilterType[])(Enum.GetValues(typeof(ControlChart.Models.FilterType)))
select new SelectListItem() {
Text = ((DisplayAttribute)(typeof(FilterType).GetField(v.ToString()).GetCustomAttributes(typeof(DisplayAttribute), false).First())).Name,
Value = v.ToString(),
Selected = v == Model.Filter
})
HTH
Maybe is too late, but i think it could be useful for people with the same problem.
I've found here that now with MVC 5 it's included an EnumDropDownListFor html helper that makes for no longer necesary the use of custom helpers or other workarounds.
In this particular case, just add this:
#Html.EnumDropDownListFor(x => x.SelectedCurrency)
and that's all!
You can also translate or change the displayed text via data annotations and resources files:
Add the following data annotations to your enum:
public enum Currencies
{
[Display(Name="Currencies_CAD", ResourceType=typeof(Resources.Enums)]
CAD,
[Display(Name="Currencies_USD", ResourceType=typeof(Resources.Enums)]
USD,
[Display(Name="Currencies_EUR", ResourceType=typeof(Resources.Enums)]
EUR
}
Create the corresponding resources file.

Resources