Linq projection how to check for null collection from select statement - linq

I am converting an object to XML using linq and got stuck with a problem below (simplified for brevity):
public class Job
{
public string JobNumber{ get; set; }
public string ClientType { get; set; }
public List<ChildItem> ChildItems { get; set; }
}
public class ChildItem
{
public string Id{ get; set; }
}
var data = DAL.GetJobs();
var xml = new XElement("records",
data.Select(i => new XElement("record",
new XAttribute("JobNumber", i.JobNumber),
new XAttribute("ClientType", i.ClientType),
new XElement("Items",
i.ChildItems.Select(j=>new XElement("Item",
new XAttribute("ID", j.Id)
))))));
The above code works fine when ChildItems is initialised and gives
<records>
<record JobNumber="12" ClientType="ABC">
<Items>
<Item ID="1"/>
<Item ID="2"/>
</Items>
</record>
</records>
However, when the Childitems is null in job it throws an error. In case of null all I want to output is:
<records>
<record JobNumber="12" ClientType="ABC">
<Items>
</Items>
</record>
</records>
However, I am not able to figure out how to check for null from within the Select?
Any solutions?

Please try the below code, which working fine for me.
var data = new List<Job> { new Job { JobNumber = "12", ClientType = "ABC" } };
var xml = new XElement("records",
data.Select(i => new XElement("record",
new XAttribute("JobNumber", i.JobNumber),
new XAttribute("ClientType", i.ClientType),
new XElement("Items",
(i.ChildItems ?? new List<ChildItem>()).Select(j => new XElement("Item",
new XAttribute("ID", j.Id)
))))));
Console.WriteLine(xml.CreateNavigator().OuterXml);

Related

how to save a picker value to the web api using the mvvm properties in the command?

I have a xamarin forms application and would like to save some values ​​that I got from the picker via the web api. The objective is to save this value as well as the other properties in the web api that is linked to the sql server database, but I have issues in how to reference the value selected in the picker through mvvm. I can load the data from the picker but I just don't know how to save these values ​​by referencing the picker in mvvm.
UsuarioModel Class
This is the model class, it has the CodPerfil property which is the foreign key that should be stored in my web api database and must correspond to the value that will be selected in the picker.
public class UsuarioModel
{
public int CodUsuario { get; set; }
public string Nome { get; set; }
public string Senha { get; set; }
public int Telefone { get; set; }
public DateTime DataRegisto { get; set; }
public bool Estado { get; set; }
public int CodPerfil { get; set; }
}
PerfilModel Class
public class PerfilModel
{
public int CodPerfil { get; set; }
public string Titulo { get; set; }
}
Web API Controller to Insert Data
public IHttpActionResult Registo(UsuarioModel usuario)
{
connection();
SqlCommand cmd = new SqlCommand("SpAddNewUser", conn);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("#Nome", usuario.Nome);
cmd.Parameters.AddWithValue("#Senha", usuario.Senha);
cmd.Parameters.AddWithValue("#Telefone", usuario.Telefone);
cmd.Parameters.AddWithValue("#CodPerfil", usuario.CodPerfil);
conn.Open();
cmd.ExecuteNonQuery();
return Ok();
}
Web API Controller to Get Data for Picker in Xamarin
public IEnumerable<PerfilModel> GetPerfisApp()
{
List<PerfilModel> perfilModels = new List<PerfilModel>();
connection();
SqlCommand cmd = new SqlCommand("SpGetPerfilApp", conn);
cmd.CommandType = CommandType.StoredProcedure;
conn.Open();
SqlDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
PerfilModel perfil = new PerfilModel();
perfil.CodPerfil = Convert.ToInt32(reader["CodPerfil"]);
perfil.Titulo = reader["Titulo"].ToString();
perfilModels.Add(perfil);
}
conn.Close();
return perfilModels;
}
ViewModel Class
public class AddRegistoUsuarioViewModel : BaseViewModel
{
ApiServices _apiServices = new ApiServices();
string _nome;
public string Nome
{
get
{
return _nome;
}
set
{
if (value != null)
{
_nome = value;
OnPropertyChanged();
}
}
}
string _senha;
public string Senha
{
get
{
return _senha;
}
set
{
if (value != null)
{
_senha = value;
OnPropertyChanged();
}
}
}
int _telefone;
public int Telefone
{
get
{
return _telefone;
}
set
{
_telefone = value;
OnPropertyChanged();
}
}
int _codperfil;
public int CodPerfil
{
get
{
return _codperfil;
}
set
{
_codperfil = value;
OnPropertyChanged();
}
}
public string Message { get; set; }
public ICommand Registar
{
get
{
return new Command(async () =>
{
var usuario = new UsuarioModel
{
Nome = Nome,
Senha = Senha,
Telefone = Telefone,
CodPerfil = SelectedPerfil.CodPerfil
};
await _apiServices.RegistoUsuarioAsync(usuario);
});
}
}
public AddRegistoUsuarioViewModel()
{
GetPerfisApp();
}
public async void GetPerfisApp()
{
using (var client = new HttpClient())
{
var uri = "https://webapiigarbage-ff4.conveyor.cloud/api/Usuario/PerfisApp";
var result = await client.GetStringAsync(uri);
var PerfilList = JsonConvert.DeserializeObject<List<PerfilModel>>(result);
Perfis = new ObservableCollection<PerfilModel>(PerfilList);
}
}
PerfilModel _selectedPerfil;
public PerfilModel SelectedPerfil
{
get
{
return _selectedPerfil;
}
set
{
if (SelectedPerfil != value)
{
_selectedPerfil = value;
OnPropertyChanged();
}
}
}
ObservableCollection<PerfilModel> _perfis;
public ObservableCollection<PerfilModel> Perfis
{
get
{
return _perfis;
}
set
{
_perfis = value;
OnPropertyChanged();
}
}
}
API Service Class
I tried to use this form: CodPerfil = SelectedPerfil.CodPerfil
But I was not successful.
public async Task RegistoUsuarioAsync(UsuarioModel usuario)
{
var client = new HttpClient();
var json = JsonConvert.SerializeObject(usuario);
HttpContent content = new StringContent(json);
content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
var response = await client.PostAsync("https://mywebsite/api/Usuario/Registo", content);
}
RegisterPage.xaml.cs
public RegisterPage()
{
InitializeComponent();
BindingContext = new RegistoUsuarioViewModel();
}
RegisterPage.xaml
<Entry Placeholder="Nome de Usuário"
x:Name="NomeEntry" />
<Picker x:Name="PerfilPicker" Title="Selecione o seu Perfil" FontSize="Large" HorizontalOptions="Center"
ItemsSource="{Binding Perfis}"
ItemDisplayBinding="{Binding Titulo}"
SelectedItem="{Binding SelectedPerfil}" />
<Entry Placeholder="Número de Telemóvel"
x:Name="TelefoneEntry"
Keyboard="Telephone"/>
<Entry Placeholder="Senha" x:Name="SenhaEntry" IsPassword="True"/>
<Button Text="Registar"
TextColor="White"
BackgroundColor="#07E3B0"
x:Name="ButtonLogin"
Command="{Binding Registar}"/>
I would be grateful if someone could help me.
thanks for the tips. what happened was that the viewmodel that was being binded in the Register.xaml.cs class was not the one that contained the Register command. I solve the 'problem' by replacing the viewmodel and it worked!
RegisterPage.xaml.cs
public RegisterPage()
{
InitializeComponent();
BindingContext = new AddRegistoUsuarioViewModel();
}

Blazor EditForm Validation not working when using Child Component

I have a Blazor component called EditOffice. It looks as follows:
<EditForm Model="#Office" OnValidSubmit="#HandleValidSubmit">
<DataAnnotationsValidator />
<ValidationSummary />
<InputTextRow Label="Name" #bind-Value="#Office.Name" Placeholder="Enter name" />
<InputTextRow Label="ABN" #bind-Value="#Office.ABN" Placeholder="Enter ABN" />
...
<button type="submit" class="btn btn-primary edit-btn">Save office</button>
</EditForm>
I created child components called InputTextRow in an attempt to Tidy my code. They look as follows:
<div class="form-group row">
<label for="#Id" class="col-sm-3">#Label: </label>
<InputText id="#Id" #oninput="OnValueChanged" #bind-Value="#Value" class="form-control col-sm-8" placeholder="#Placeholder"></InputText>
<ValidationMessage class="offset-sm-3 col-sm-8" For="#(() => Value)" />
</div>
#code {
public string Id => Label.ToLower().Replace(" ", "");
[Parameter]
public string Label { get; set; }
[Parameter]
public string Value { get; set; }
[Parameter]
public string Placeholder { get; set; }
[Parameter] public EventCallback<string> ValueChanged { get; set; }
Task OnValueChanged(ChangeEventArgs e)
{
Value = e.Value.ToString();
return ValueChanged.InvokeAsync(Value);
}
}
The ValidationMessage doesn't work when in my child component. Any idea why?
I know I'm a little late but here is my answer :)
So there is better solution right now.
TL:DR Solution for lazy ones
Be advised - it's experimental, but package is already in release candidate so no worries I guess.
Use Microsoft.AspNetCore.Components.DataAnnotations.Validation package and <ObjectGraphDataAnnotationsValidator /> instead of <DataAnnotationsValidator /> and use this thingy:
using System.ComponentModel.DataAnnotations;
public class YourComplexModel
{
// other properties
[ValidateComplexType] // <--life saver
public ChildModel ChildModel { get; set; } = new ChildModel();
}
Fragment from MS Docs
Link Microsoft Docs:
Blazor provides support for validating form input using data annotations with the built-in DataAnnotationsValidator. However, the DataAnnotationsValidator only validates top-level properties of the model bound to the form that aren't collection- or complex-type properties.
To validate the bound model's entire object graph, including collection- and complex-type properties, use the ObjectGraphDataAnnotationsValidator provided by the experimental Microsoft.AspNetCore.Components.DataAnnotations.Validation package:
<EditForm Model="#model" OnValidSubmit="#HandleValidSubmit">
<ObjectGraphDataAnnotationsValidator />
...
</EditForm>
Annotate model properties with [ValidateComplexType]. In the following model classes, the ShipDescription class contains additional data annotations to validate when the model is bound to the form:
Starship.cs:
using System;
using System.ComponentModel.DataAnnotations;
public class Starship
{
...
[ValidateComplexType]
public ShipDescription ShipDescription { get; set; } =
new ShipDescription();
...
}
ShipDescription.cs:
using System;
using System.ComponentModel.DataAnnotations;
public class ShipDescription
{
[Required]
[StringLength(40, ErrorMessage = "Description too long (40 char).")]
public string ShortDescription { get; set; }
[Required]
[StringLength(240, ErrorMessage = "Description too long (240 char).")]
public string LongDescription { get; set; }
}
I am having exactly the same issue. My code is very similar to yours. My child component do validate, but the validation error message is not displayed.
I do use this extension method:
using System;
using Microsoft.AspNetCore.Components.Forms;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
namespace TimeRecording.Extensions
{
public static class EditContextExtensions
{
static PropertyInfo IsModifiedProperty;
static MethodInfo GetFieldStateMethod;
/// <summary>
/// Validates an entire object tree
/// </summary>
/// <param name="editContext">The EditContext to validate the Model of</param>
/// <returns>True if valid, otherwise false</returns>
public static bool ValidateObjectTree(this EditContext editContext)
{
var validatedObjects = new HashSet<object>();
ValidateObject(editContext, editContext.Model, validatedObjects);
editContext.NotifyValidationStateChanged();
return !editContext.GetValidationMessages().Any();
}
public static void ValidateProperty(this EditContext editContext, FieldIdentifier fieldIdentifier)
{
if (fieldIdentifier.Model == null)
return;
var propertyInfo = fieldIdentifier.Model.GetType().GetProperty(
fieldIdentifier.FieldName,
BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Static);
var validatedObjects = new HashSet<object>();
ValidateProperty(editContext, fieldIdentifier.Model, propertyInfo, validatedObjects);
}
private static void ValidateObject(
EditContext editContext,
object instance,
HashSet<object> validatedObjects)
{
if (instance == null)
return;
if (validatedObjects.Contains(instance))
return;
if (instance is IEnumerable && !(instance is string))
{
foreach (object value in (IEnumerable)instance)
ValidateObject(editContext, value, validatedObjects);
return;
}
if (instance.GetType().Assembly == typeof(string).Assembly)
return;
validatedObjects.Add(instance);
var properties = instance.GetType().GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
foreach (PropertyInfo property in properties)
ValidateProperty(editContext, instance, property, validatedObjects);
}
private static void ValidateProperty(
EditContext editContext,
object instance,
PropertyInfo property,
HashSet<object> validatedObjects)
{
NotifyPropertyChanged(editContext, instance, property.Name);
object value = property.GetValue(instance);
ValidateObject(editContext, value, validatedObjects);
}
private static void NotifyPropertyChanged(
EditContext editContext,
object instance,
string propertyName)
{
if (GetFieldStateMethod == null)
{
GetFieldStateMethod = editContext.GetType().GetMethod(
"GetFieldState",
BindingFlags.NonPublic | BindingFlags.Instance);
}
var fieldIdentifier = new FieldIdentifier(instance, propertyName);
object fieldState = GetFieldStateMethod.Invoke(editContext, new object[] { fieldIdentifier, true });
if (IsModifiedProperty == null)
{
IsModifiedProperty = fieldState.GetType().GetProperty(
"IsModified",
BindingFlags.Public | BindingFlags.Instance);
}
object originalIsModified = IsModifiedProperty.GetValue(fieldState);
editContext.NotifyFieldChanged(fieldIdentifier);
IsModifiedProperty.SetValue(fieldState, originalIsModified);
}
}
}

Mvc 3: Populating a dropdown box

I know this is very simple but new to Mvc. I will like to populate a dropdownbox with data
from the GetDescription method such that the dropdown shows the Description and when selected the code is passed as the value.
How can I write the html piece?
public class HomeController : Controller
{
public ActionResult Index()
{
return View();
}
public static List<Populate> GetDescription()
{
List<Populate> myInfor = new List<Populate>()
{
new Populate{Id=1,Description="Lagos", Code="lag"},
new Populate{Id=2,Description="Ibadan", Code="lba"},
new Populate{Id=3,Description="Akure", Code="Aku"},
new Populate{Id=4,Description="Ejigbo", Code="Eji"},
new Populate{Id=5,Description="Oshogbo", Code="Osh"}
};
return myInfor;
}
}
public class Populate
{
public int Id { get; set; }
public string Description { get; set; }
public string Code { get; set; }
}
Here is the html
*********************
#model PopulateDropDownList.Models.Populate
#{
ViewBag.Title = "Index";
}
<h2>Index</h2>
<p>
#Html.DropDownList(Model.id, Model.Description, "--Select One--")
</p>
You may also do it like that.
Modify a bit your code:
public static class Helper
{
public static List<SelectListItem> GetDescription()
{
List<Populate> myInfor = new List<Populate>()
{
new Populate{Id=1,Description="Lagos", Code="lag"},
new Populate{Id=2,Description="Ibadan", Code="lba"},
new Populate{Id=3,Description="Akure", Code="Aku"},
new Populate{Id=4,Description="Ejigbo", Code="Eji"},
new Populate{Id=5,Description="Oshogbo", Code="Osh"}
};
var result = new List<SelectListItem>();
var items = from n in myInfor
select new SelectListItem
{
Text = n.Description,
Value = n.Id.toString()
};
foreach (var item in items)
result.Add(item);
return result;
}
}
Than in your View:
#using YourProject.Helper
#Html.DropDownList("AnyTextAsID", Helper.GetDescription())
You could do this in your view:
#{
Dictionary<string, string> populate = new Dictionary<string, string>();
populate.Add("Lagos", "lag");
populate.Add("Ibadan", "lba");
populate.Add("Akure", "aku");
populate.Add("Ejigbo", "eji");
populate.Add("Oshogbo", "osh");
}
#Html.DropDownList("myinfo", new SelectList(populate.ToList(), "Value", "Key", "Lagos"), new { id = "Populate" })

can I use AdditionalMetadata with editor template in mvc3?

I need to create a editor template for diferent type of data for example: for string I need a EditorTemplate for largeString and for shortstring
I see that the best way for me is using editor template. so can I use AdditionalMetadata? for something like this?
[UIHint("StringLarge")]
[AdditionalMetadata("width", "50px")]
public DateTime Date { get; set; }
My editor Template StringLarge.cshtml
#inherits System.Web.Mvc.WebViewPage<System.String>
if("have AdditionalMetadata"){
#Html.TextBox("", Model, new { #class = "StringLarge" })
}
else
{
#Html.TextBox("", Model, new { #class = "StringShort" })
}
Can I do that or just create separtes EditorTemplate for stringLarge and StringShort?
You can do that by writing a custom attribute implementing the IMetadataAware interface:
public class MyStringsAttribute : Attribute, IMetadataAware
{
private readonly string _value;
public MyStringsAttribute(string value)
{
_value = value;
}
public void OnMetadataCreated(ModelMetadata metadata)
{
metadata.TemplateHint = "Strings";
metadata.AdditionalValues["someKey"] = _value;
}
}
and then:
[MyStrings("somevalue")]
public DateTime Date { get; set; }
and finally inside your custom editor template (~/Views/Shared/EditorTemplates/Strings.cshtml) you could check for the presence of this additional metadata:
#{
var additionalMetadata = (string)ViewData.ModelMetadata.AdditionalValues["someKey"];
}
#if (string.Equals(additionalMetadata, "somevalue"))
{
...
}
else
{
...
}
using [AdditionalMetadata]
ViewModel:
[UIHint("StringCorto")]
[AdditionalMetadata("style", "width:100px")]
public string Nit { get; set; }
Editor Template:
#inherits System.Web.Mvc.WebViewPage<System.String>
#{
this.ViewData.ModelMetadata.AdditionalValues.Add("class", "StringCorto");
}
#Html.TextBox(string.Empty, ViewContext.ViewData.TemplateInfo.FormattedModelValue, this.ViewData.ModelMetadata.AdditionalValues)

RequiredIf Conditional Validation Attribute

I was looking for some advice on the best way to go about implementing a validation attribute that does the following.
Model
public class MyInputModel
{
[Required]
public int Id {get;set;}
public string MyProperty1 {get;set;}
public string MyProperty2 {get;set;}
public bool MyProperty3 {get;set;}
}
I want to have atleast prop1 prop2 prop3 with a value and if prop3 is the only value filled it it should not equal false.
How would i go about writing a validation attribute(s?) for this?
Thanks for any help!
I had the same problem yesterday, but I did it in a very clean way which works for both client side and server side validation.
Condition: Based on the value of other property in the model, you want to make another property required. Here is the code:
public class RequiredIfAttribute : RequiredAttribute
{
private String PropertyName { get; set; }
private Object DesiredValue { get; set; }
public RequiredIfAttribute(String propertyName, Object desiredvalue)
{
PropertyName = propertyName;
DesiredValue = desiredvalue;
}
protected override ValidationResult IsValid(object value, ValidationContext context)
{
Object instance = context.ObjectInstance;
Type type = instance.GetType();
Object proprtyvalue = type.GetProperty(PropertyName).GetValue(instance, null);
if (proprtyvalue.ToString() == DesiredValue.ToString())
{
ValidationResult result = base.IsValid(value, context);
return result;
}
return ValidationResult.Success;
}
}
PropertyName is the property on which you want to make your condition
DesiredValue is the particular value of the PropertyName (property) for which your other property has to be validated for required
Say you have the following:
public enum UserType
{
Admin,
Regular
}
public class User
{
public UserType UserType {get;set;}
[RequiredIf("UserType",UserType.Admin,
ErrorMessageResourceName="PasswordRequired",
ErrorMessageResourceType = typeof(ResourceString))]
public string Password { get; set; }
}
At last but not the least, register adapter for your attribute so that it can do client side validation (I put it in global.asax, Application_Start)
DataAnnotationsModelValidatorProvider.RegisterAdapter(typeof(RequiredIfAttribute),
typeof(RequiredAttributeAdapter));
EDITED
Some people have reported issues that the client side fires no matter what or it does not work. So I modified the above code to do conditional client side validation with Javascript as well. For this case you don't need to register adapter
public class RequiredIfAttribute : ValidationAttribute, IClientValidatable
{
private String PropertyName { get; set; }
private Object DesiredValue { get; set; }
private readonly RequiredAttribute _innerAttribute;
public RequiredIfAttribute(String propertyName, Object desiredvalue)
{
PropertyName = propertyName;
DesiredValue = desiredvalue;
_innerAttribute = new RequiredAttribute();
}
protected override ValidationResult IsValid(object value, ValidationContext context)
{
var dependentValue = context.ObjectInstance.GetType().GetProperty(PropertyName).GetValue(context.ObjectInstance, null);
if (dependentValue.ToString() == DesiredValue.ToString())
{
if (!_innerAttribute.IsValid(value))
{
return new ValidationResult(FormatErrorMessage(context.DisplayName), new[] { context.MemberName });
}
}
return ValidationResult.Success;
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelClientValidationRule
{
ErrorMessage = ErrorMessageString,
ValidationType = "requiredif",
};
rule.ValidationParameters["dependentproperty"] = (context as ViewContext).ViewData.TemplateInfo.GetFullHtmlFieldId(PropertyName);
rule.ValidationParameters["desiredvalue"] = DesiredValue is bool ? DesiredValue.ToString().ToLower() : DesiredValue;
yield return rule;
}
}
And finally the javascript ( bundle it and renderit...put it in its own script file)
$.validator.unobtrusive.adapters.add('requiredif', ['dependentproperty', 'desiredvalue'], function (options) {
options.rules['requiredif'] = options.params;
options.messages['requiredif'] = options.message;
});
$.validator.addMethod('requiredif', function (value, element, parameters) {
var desiredvalue = parameters.desiredvalue;
desiredvalue = (desiredvalue == null ? '' : desiredvalue).toString();
var controlType = $("input[id$='" + parameters.dependentproperty + "']").attr("type");
var actualvalue = {}
if (controlType == "checkbox" || controlType == "radio") {
var control = $("input[id$='" + parameters.dependentproperty + "']:checked");
actualvalue = control.val();
} else {
actualvalue = $("#" + parameters.dependentproperty).val();
}
if ($.trim(desiredvalue).toLowerCase() === $.trim(actualvalue).toLocaleLowerCase()) {
var isValid = $.validator.methods.required.call(this, value, element, parameters);
return isValid;
}
return true;
});
You need obviously the unobstrusive validate jQuery to be included as requirement
I know the topic was asked some time ago, but recently I had faced similar issue and found yet another, but in my opinion a more complete solution. I decided to implement mechanism which provides conditional attributes to calculate validation results based on other properties values and relations between them, which are defined in logical expressions.
Using it you are able to achieve the result you asked about in the following manner:
[RequiredIf("MyProperty2 == null && MyProperty3 == false")]
public string MyProperty1 { get; set; }
[RequiredIf("MyProperty1 == null && MyProperty3 == false")]
public string MyProperty2 { get; set; }
[AssertThat("MyProperty1 != null || MyProperty2 != null || MyProperty3 == true")]
public bool MyProperty3 { get; set; }
More information about ExpressiveAnnotations library can be found here. It should simplify many declarative validation cases without the necessity of writing additional case-specific attributes or using imperative way of validation inside controllers.
I got it to work on ASP.NET MVC 5
I saw many people interested in and suffering from this code and i know it's really confusing and disrupting for the first time.
Notes
worked on MVC 5 on both server and client side :D
I didn't install "ExpressiveAnnotations" library at all.
I'm taking about the Original code from "#Dan Hunex", Find him above
Tips To Fix This Error
"The type System.Web.Mvc.RequiredAttributeAdapter must have a public constructor which accepts three parameters of types System.Web.Mvc.ModelMetadata, System.Web.Mvc.ControllerContext, and ExpressiveAnnotations.Attributes.RequiredIfAttribute Parameter name: adapterType"
Tip #1: make sure that you're inheriting from 'ValidationAttribute' not from 'RequiredAttribute'
public class RequiredIfAttribute : ValidationAttribute, IClientValidatable { ...}
Tip #2: OR remove this entire line from 'Global.asax', It is not needed at all in the newer version of the code (after edit by #Dan_Hunex), and yes this line was a must in the old version ...
DataAnnotationsModelValidatorProvider.RegisterAdapter(typeof(RequiredIfAttribute), typeof(RequiredAttributeAdapter));
Tips To Get The Javascript Code Part Work
1- put the code in a new js file (ex:requiredIfValidator.js)
2- warp the code inside a $(document).ready(function(){........});
3- include our js file after including the JQuery validation libraries, So it look like this now :
#Scripts.Render("~/bundles/jqueryval")
<script src="~/Content/JS/requiredIfValidator.js"></script>
4- Edit the C# code
from
rule.ValidationParameters["dependentproperty"] = (context as ViewContext).ViewData.TemplateInfo.GetFullHtmlFieldId(PropertyName);
to
rule.ValidationParameters["dependentproperty"] = PropertyName;
and from
if (dependentValue.ToString() == DesiredValue.ToString())
to
if (dependentValue != null && dependentValue.ToString() == DesiredValue.ToString())
My Entire Code Up and Running
Global.asax
Nothing to add here, keep it clean
requiredIfValidator.js
create this file in ~/content or in ~/scripts folder
$.validator.unobtrusive.adapters.add('requiredif', ['dependentproperty', 'desiredvalue'], function (options)
{
options.rules['requiredif'] = options.params;
options.messages['requiredif'] = options.message;
});
$(document).ready(function ()
{
$.validator.addMethod('requiredif', function (value, element, parameters) {
var desiredvalue = parameters.desiredvalue;
desiredvalue = (desiredvalue == null ? '' : desiredvalue).toString();
var controlType = $("input[id$='" + parameters.dependentproperty + "']").attr("type");
var actualvalue = {}
if (controlType == "checkbox" || controlType == "radio") {
var control = $("input[id$='" + parameters.dependentproperty + "']:checked");
actualvalue = control.val();
} else {
actualvalue = $("#" + parameters.dependentproperty).val();
}
if ($.trim(desiredvalue).toLowerCase() === $.trim(actualvalue).toLocaleLowerCase()) {
var isValid = $.validator.methods.required.call(this, value, element, parameters);
return isValid;
}
return true;
});
});
_Layout.cshtml or the View
#Scripts.Render("~/bundles/jqueryval")
<script src="~/Content/JS/requiredIfValidator.js"></script>
RequiredIfAttribute.cs Class
create it some where in your project, For example in ~/models/customValidation/
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Web.Mvc;
namespace Your_Project_Name.Models.CustomValidation
{
public class RequiredIfAttribute : ValidationAttribute, IClientValidatable
{
private String PropertyName { get; set; }
private Object DesiredValue { get; set; }
private readonly RequiredAttribute _innerAttribute;
public RequiredIfAttribute(String propertyName, Object desiredvalue)
{
PropertyName = propertyName;
DesiredValue = desiredvalue;
_innerAttribute = new RequiredAttribute();
}
protected override ValidationResult IsValid(object value, ValidationContext context)
{
var dependentValue = context.ObjectInstance.GetType().GetProperty(PropertyName).GetValue(context.ObjectInstance, null);
if (dependentValue != null && dependentValue.ToString() == DesiredValue.ToString())
{
if (!_innerAttribute.IsValid(value))
{
return new ValidationResult(FormatErrorMessage(context.DisplayName), new[] { context.MemberName });
}
}
return ValidationResult.Success;
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelClientValidationRule
{
ErrorMessage = ErrorMessageString,
ValidationType = "requiredif",
};
rule.ValidationParameters["dependentproperty"] = PropertyName;
rule.ValidationParameters["desiredvalue"] = DesiredValue is bool ? DesiredValue.ToString().ToLower() : DesiredValue;
yield return rule;
}
}
}
The Model
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;
using Your_Project_Name.Models.CustomValidation;
namespace Your_Project_Name.Models.ViewModels
{
public class CreateOpenActivity
{
public Nullable<int> ORG_BY_CD { get; set; }
[RequiredIf("ORG_BY_CD", "5", ErrorMessage = "Coordinator ID is required")] // This means: IF 'ORG_BY_CD' is equal 5 (for the example) > make 'COR_CI_ID_NUM' required and apply its all validation / data annotations
[RegularExpression("[0-9]+", ErrorMessage = "Enter Numbers Only")]
[MaxLength(9, ErrorMessage = "Enter a valid ID Number")]
[MinLength(9, ErrorMessage = "Enter a valid ID Number")]
public string COR_CI_ID_NUM { get; set; }
}
}
The View
Nothing to note here actually ...
#model Your_Project_Name.Models.ViewModels.CreateOpenActivity
#{
ViewBag.Title = "Testing";
}
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>CreateOpenActivity</h4>
<hr />
#Html.ValidationSummary(true, "", new { #class = "text-danger" })
<div class="form-group">
#Html.LabelFor(model => model.ORG_BY_CD, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.ORG_BY_CD, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.ORG_BY_CD, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.COR_CI_ID_NUM, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.COR_CI_ID_NUM, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.COR_CI_ID_NUM, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</div>
</div>
}
I may upload a project sample for this later ...
Hope this was helpful
Thank You
If you try to use "ModelState.Remove" or "ModelState["Prop"].Errors.Clear()" the "ModelState.IsValid" stil returns false.
Why not just removing the default "Required" Annotation from Model and make your custom validation before the "ModelState.IsValid" on Controller 'Post' action? Like this:
if (!String.IsNullOrEmpty(yourClass.Property1) && String.IsNullOrEmpty(yourClass.dependantProperty))
ModelState.AddModelError("dependantProperty", "It´s necessary to select some 'dependant'.");
Expanding on the notes from Adel Mourad and Dan Hunex, I amended the code to provide an example that only accepts values that do not match the given value.
I also found that I didn't need the JavaScript.
I added the following class to my Models folder:
public class RequiredIfNotAttribute : ValidationAttribute, IClientValidatable
{
private String PropertyName { get; set; }
private Object InvalidValue { get; set; }
private readonly RequiredAttribute _innerAttribute;
public RequiredIfNotAttribute(String propertyName, Object invalidValue)
{
PropertyName = propertyName;
InvalidValue = invalidValue;
_innerAttribute = new RequiredAttribute();
}
protected override ValidationResult IsValid(object value, ValidationContext context)
{
var dependentValue = context.ObjectInstance.GetType().GetProperty(PropertyName).GetValue(context.ObjectInstance, null);
if (dependentValue.ToString() != InvalidValue.ToString())
{
if (!_innerAttribute.IsValid(value))
{
return new ValidationResult(FormatErrorMessage(context.DisplayName), new[] { context.MemberName });
}
}
return ValidationResult.Success;
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelClientValidationRule
{
ErrorMessage = ErrorMessageString,
ValidationType = "requiredifnot",
};
rule.ValidationParameters["dependentproperty"] = (context as ViewContext).ViewData.TemplateInfo.GetFullHtmlFieldId(PropertyName);
rule.ValidationParameters["invalidvalue"] = InvalidValue is bool ? InvalidValue.ToString().ToLower() : InvalidValue;
yield return rule;
}
I didn't need to make any changes to my view, but did make a change to the properties of my model:
[RequiredIfNot("Id", 0, ErrorMessage = "Please select a Source")]
public string TemplateGTSource { get; set; }
public string TemplateGTMedium
{
get
{
return "Email";
}
}
[RequiredIfNot("Id", 0, ErrorMessage = "Please enter a Campaign")]
public string TemplateGTCampaign { get; set; }
[RequiredIfNot("Id", 0, ErrorMessage = "Please enter a Term")]
public string TemplateGTTerm { get; set; }
Hope this helps!
The main difference from other solutions here is that this one reuses logic in RequiredAttribute on the server side, and uses required's validation method depends property on the client side:
public class RequiredIf : RequiredAttribute, IClientValidatable
{
public string OtherProperty { get; private set; }
public object OtherPropertyValue { get; private set; }
public RequiredIf(string otherProperty, object otherPropertyValue)
{
OtherProperty = otherProperty;
OtherPropertyValue = otherPropertyValue;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
PropertyInfo otherPropertyInfo = validationContext.ObjectType.GetProperty(OtherProperty);
if (otherPropertyInfo == null)
{
return new ValidationResult($"Unknown property {OtherProperty}");
}
object otherValue = otherPropertyInfo.GetValue(validationContext.ObjectInstance, null);
if (Equals(OtherPropertyValue, otherValue)) // if other property has the configured value
return base.IsValid(value, validationContext);
return null;
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelClientValidationRule();
rule.ErrorMessage = FormatErrorMessage(metadata.GetDisplayName());
rule.ValidationType = "requiredif"; // data-val-requiredif
rule.ValidationParameters.Add("other", OtherProperty); // data-val-requiredif-other
rule.ValidationParameters.Add("otherval", OtherPropertyValue); // data-val-requiredif-otherval
yield return rule;
}
}
$.validator.unobtrusive.adapters.add("requiredif", ["other", "otherval"], function (options) {
var value = {
depends: function () {
var element = $(options.form).find(":input[name='" + options.params.other + "']")[0];
return element && $(element).val() == options.params.otherval;
}
}
options.rules["required"] = value;
options.messages["required"] = options.message;
});
I think using IValidatableObject is a good choice.
public class MyInputModel : IValidateObject
{
[Required]
public int Id {get;set;}
public string MyProperty1 {get;set;}
public string MyProperty2 {get;set;}
public bool MyProperty3 {get;set;}
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
if (MyProperty1==null&&MyProperty2==null&&MyPropterty3!=false) //whatever condition
{
yield return new ValidationResult(
"Custom complex error");
}
}
}

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