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How to get all model validation errors in ASP.NET MVC?

In ASP.NET MVC you can get a list of all validation errors for your model from the ModelState

if (!ModelState.IsValid)
{
var modelErrors = new List<string>();
foreach (var modelState in ModelState.Values)
{
foreach (var modelError in modelState.Errors)
{
modelErrors.Add(modelError.ErrorMessage);
}
}
// Here you have the list of error, you can show them on the view or generate a erro string and display it using javascript.
}

If you want to display it in razor then you can use @Html.ValidationSummary().

Hope it will help to find the actual error from the modal state.

Explore Action Filters in Asp.Net MVC Applications

What is Action Filters

In the Asp.Net MVC application there are controllers, each controller defines action methods that generally have one to one relation ship with views or each actions use performs on the page.
User actions means we can say like clicking on buttons, links or submitting a form. When this kind of action performs request is routed to controller and finds the action method.
Now if we want to perform some action, calculate login or check some values either before calling an action method or after action method completes Action Filters are used.

Asp.Net MVC provides actions filters which we can say custom attributes which provides facility to perform some behavior at pre-action or post-action time of controller action method.

Now lets see the available types of the Action filter in Asp.Net MVC

Action Filter Types

Asp.Net MVC provides 4 types of action filters like Authorization filter, Action filter, Result filter and Exception filter. Please find the below description for each type of action filter.

Authorization filter

Generally it is used to implement authorization and authentication for action method, It is related to security of the application whether to execute action method or not, it also check for the authentication and request property.
As an example you can see AuthorizeAttribute class for Authorization action filter.

Action filter

Generally it is used to perform some extra processing, like before executing any action method we want to check like user is logged in or not, or user has enough permission to execute this action method or not.
If session expired and we want to transfer request to login page etc.

Result filter

Generally it is used to perform extra processing of the result like modifying the response that means if we want to execute a login before or after the view result get executes we can use this filters.
As an example you can see OutputCacheAttribute class for result filter.

Exception filter

It executes when ever there is an unhanded exception thrown by anywhere in the action method. Exception filters can be used for the tasks like logging an error or displaying an error page 404
As an example you can see HandleErrorAttribute class for exception filter.

Serialization & Deserialization using JSON In C#

Introduction

The very useful method of converting JSON object to .Net object and .Net object to Json object is using the JsonConvert. It converts Json objects to .Net object and with the Same property with value and .Net objects to equivalent JSON object.

In this article we will see how to serialize .NET type objects into JSON object and then deserialize data in the JSON format back into .NET types using the JsonConvert class.

What is JSON?

JSON (JavaScript Object Notation) is one lightweight and efficient data exchange format or we can say like JSON is most desirable data encoding format which allows fast exchanges of small amounts of data between client browsers and web services or web api.

JsonConvert

JsonConvert class is in the namespace “Newtonsoft.Json” and for this namespace you need to add reference of Newtonsoft.Json dll or nuget package. You can install a Newtonsoft.Json nuget package by command “Install-Package Newtonsoft.Json” in package manager console.

If we want to convert .Net object to Json object then the SerializeObject() method will be used and when we want to convert Json object back to .Net object then DeserializeObject() method will be used from the JsonConvert class

JSON Serialization

Now lets see the JSON Serialization process with code example, we have an instance of Customer class as below

public class Customer
{
public int Id { get; set; }
public string Name { get; set; }
public string Email { get; set; }
public string PhoneNo { get; set; }
}

Now create an object of Customer class and initilize value of each properties. Then call SerializeObject() of JsonConvert class with passing Customer object.
See the below codesnippet

// Serializaion .Net Object
Customer customer = new Customer();
customer.Id = 1;
customer.Name = "Tarun Dudhatra";
customer.Email = "email@address.com";
customer.PhoneNo = "5*9*9 5*8*5";

// Convert Customer object to JOSN encoded format
string jsonDataString = JsonConvert.SerializeObject(customer);

Console.Write(jsonDataString);
Console.ReadKey();

It will return the JSON string as below

{"Id":1,"Name":"Tarun Dudhatra","Email":"email@address.com","PhoneNo":"5*9*9 5*8*5"}

JSON Deserialization

See the below JSON Deserialization process with code example, we have same Customer class string as below

{"Id":2,"Name":"FirstName LastName","Email":"email@address.com","PhoneNo":"5*9*9 5*8*5"}

Now call the DeserializeObject() of JsonConvert class and pass the object type of Customer so it will deserialize it into Customer Class.
See the below codesnippet

Deserializaion JSON Object

string JSONObject = @"{ 'Id':2,'Name':'FirstName LastName','Email':'email@address.com','PhoneNo':'5*9*9 5*8*5'}";

Customer customer = JsonConvert.DeserializeObject<Customer>(JSONObject);

Console.WriteLine( "Id : " + customer.Id);
Console.WriteLine( "Name : " + customer.Name);
Console.WriteLine( "Email: " + customer.Email);
Console.WriteLine( "Phone: " + customer.PhoneNo);
Console.ReadKey();

It will print the below out put on the screen

Id : 2
Name : FirstName LastName
Email: email@address.com
Phone: 5*9*9 5*8*5

That’s it, in my upcoming article we will see other interesting stuff like this.