Models

Models in MVC

Eyal VardiCEO E4D Solutions LTDMicrosoft MVP Visual C#blog: www.eVardi.com

Models in MVC

Eyal VardiCEO E4D Solutions LTDMicrosoft MVP Visual C#blog: www.eVardi.com

© 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: [email protected]

Agenda

Integrating the Model & Controller

Model Binders

Model Validation


Model Template

What Is a Model?

Model

Controller

View HTTPHTML

Deserialization

Template


Model Attributes

Scaffolding [ScaffoldColumn]

View [HiddenInput] [Display] [DisplayName], Attribute on a Class [DataType(...)] [UIHint(...)] [AdditionalMetadata( key , value )]


Display Attribute[DisplayName("Book")] public class E4DBook {

[Display(Name = "Title")]

public string E4DTitle { get; set; } }

Model

<h2>@Html.LabelForModel()</h2>

@Html.EditorForModel()

Or

@Html.LabelFor(m => m.E4DTitle)

View


DataType Attribute

DateTime

Date

Time

Text

MultilineText

Password

Url

EmailAddress


UIHint Attribute

Use the UIHint attribute to specify the template we want to use to render HTML for a property.

[DisplayName("Book")] public class E4DBook {

[Display(Name = "Title")][DateType(DataType.MultilineText)][UIHint("MultilineText")]

public string E4DTitle { get; set; } }

Model


Built in View Template

Boolean Collection Decimal EmailAddress HiddenInput Html MultilineText

Object Password String Text Url


Model Templates


Model Binding

What Is a Model?

Model

Controller

View HTTPHTML

Deserialization

Template


HTTP to .NET Classes

public ActionResult Index(Reservation reservation){ // TODO BL. return View( reservation );} Deserialization


Model Binders

Binders are like type converters, because they can convert HTTP requests into objects that are passed to an action method.


DefaultModelBinder Class

Translate HTTP request into complex models, including nested types and arrays. URL Form data, Culture - Sensitive

1. Request.Form

2. RoutedData.Values

3. Request.QueryString

4. Request.Files

(Key,Value)


Binding to Complex Types[DisplayName("Book")] public class E4DBook {

[Display(Name = "Title")] public string E4DTitle { get; set; }

public Reservation MyReservation { get; set; } }

Model

<label for="MyReservation_FlightNum">FlightNum</label>

<input type="text" value="" id = "MyReservation_FlightNum" name = "MyReservation.FlightNum" />

Html

@Html.LabelFor(model => model.MyReservation.FlightNum) @Html.EditorFor(model => model.MyReservation.FlightNum)

View


Specifying Custom Prefixes

<!– First Arg --><label for="FlightNum">FlightNum</label><input type="text" id="FlightNum" name="FlightNum" />

...

<!– Second Arg --><label for="MyRes_FlightNum">FlightNum</label><input type="text" id="MyRes_FlightNum" name="MyRes.FlightNum" />

Html

public ActionResult Index( Reservation res1 , [Bind(Prefix="myRes")] Reservation res2 ) { ... }

Controller


Bind Attribute (“View”)

Represents an attribute that is used to provide details about how model binding to a parameter should occur.

[Bind(Include = "FlightNum, TravelDate)]public class Reservation{ public int FlightNum { get; set; } public DateTime TravelDate { get; set; } public int TicketCount { get; set; } public int DiscountPercent { get; set; }}


Bind Attribute


<input type="text" name="reservation" value="…" /><input type="text" name="reservation" value="…" /><input type="text" name="reservation" value="…" /><input type="text" name="reservation" value="…" />

Html

public ActionResult Index( List< string > reservation ) { ... }

Controller

Binding to a String Collections


Binding to a Collections

<!– Option I--><input type="text" name="[0].Name" /><input type="text" name="[1].Name" />

<!– Option II --><input type="hidden" name="Index" value="f1" /><input type="text" name="[f1].Name" />

<input type="hidden" name="Index" value="f2" /><input type="text" name="[f2].Name" />

Html

public ActionResult Index( List<Reservation> reservation ) { ... }

Controller


Binding to a Dictionary

<input type="hidden" name="[0].key" value="f1" /><input type="text" name="[0].value.Name" />

<input type="hidden" name="[1].key" value="f2" /><input type="text" name="[1].value.Name" />

Html

public ActionResult Index( Dictionary<Reservation> reservation ) { ... }

Controller


Manually Invoking Model Binding


Custom Model Binders

ASP.NET MVC allows us to override both the default model binder, as well as add custom model binders.

ModelBinders.Binders.DefaultBinder = new CustomDefaultBinder();

ModelBinders.Binders.Add( typeof(DateTime),

new DateTimeModelBinder() );


ModelBinder Attribute

Represents an attribute that is used to associate a model type to a model-builder type.

public ActionResult Contact( [ModelBinder(typeof(ContactBinder))] Contact contact ){ ViewData["name"] = contact.Name; ViewData["email"] = contact.Email; ViewData["message"] = contact.Message; ViewData["title"] = "Succes!";

return View();}


Custom Binder


Integrating The Model & Controller

public ActionResult Index(Reservation reservation){ int totalCost = reservation.TicketCount * 100;

if (reservation.DiscountPercent != 0) { totalCost -= (totalCost * reservation.DiscountPercent / 100); }

ViewBag.TotalCost = totalCost;

return View( reservation );}

Deserialization

BL

@model Reservation

Model

Index.cshtml

Business

Models