A Simple MS Enterprise Library Validation Block Example

I've been building an example on using the MS Enterprise Library Validation block for my co-workers. Here's a pretty simple step-by-step guide to getting started.

Let's start off with a Console application. (This could even be a Windows Forms application, a Windows service or a Web Application/Web Site.)

Step 1: Add references to Microsoft.Practices.EnterpriseLibrary.Common and Microsoft.Practices.EnterpriseLibrary.Validation

Step 2: Create a class that can store your data

namespace MyApplication1
{
public class UserProfile
{
public int ID { get; set; }
public string Name { get; set; }
public string Email { get; set; }
public DateTime DOB { get; set; }
public string Address { get; set; }
public string CityCode { get; set; }
}
}

Step 3 (GUI):
Start the Enterprise Library Configuration tool by going to Start > Programs > Microsoft patterns and practices > Enterprise Library 4.1 - October 2008 > Enterprise Library Configuration.

You may have a different version of the Enterprise Library installed - I'm using 4.1, but you can use 3.1 just as well.

Using the Enterprise Library Configuration tool,
(i) add a Validation Application block section,
(ii) Add a type,
(iii) Add the properties (or fields/methods, as the case may be),
(iv) Add validators to the properties (or fields/methods from iii ), and
(v) Provide the parameters for the validators, if applicable



Step 3 (Manual Config):
Add the validation configuration section in the config file (App.config or web.config) by adding the following line into the configSections tag:
<section name="validation" type="Microsoft.Practices.EnterpriseLibrary.Validation.Configuration.ValidationSettings, Microsoft.Practices.EnterpriseLibrary.Validation, Version=4.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />

You would need to change the Version and PublicKeyToken if you're using a different version of the Enterprise Library.

Create the validation section, reference the type to be validated (from Step 2), add a ruleset, define the properties for the type (only the ones you need validated), and create the validators within the type. The hierarchy is validation > type > ruleset > properties > property > validator.

<validation>
<type assemblyName="MyApplication1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="MyApplication1.UserProfile">
<ruleset name="RuleOne">
<properties>
<property name="Name">

<validator name="Not Null Validator" messageTemplate="Name must be entered" type="Microsoft.Practices.EnterpriseLibrary.Validation.Validators.NotNullValidator, Microsoft.Practices.EnterpriseLibrary.Validation, Version=4.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />

</property>
</properties>
</ruleset>
</type>
</validation>

Step 4: Add the .NET code

Add the following using statement to the top of your code file:
using Microsoft.Practices.EnterpriseLibrary.Validation;

Add the following code to perform the validation:
UserProfile usrProfile = new UserProfile();
Validator<UserProfile> validator = ValidationFactory.CreateValidator<UserProfile>("RuleOne");
ValidationResults results = validator.Validate(usrProfile);

StringBuilder strBuilder = new StringBuilder();
foreach (ValidationResult iterResult in results) {
strBuilder.Append(iterResult.Message + "\n");
}

Console.WriteLine(results.isValid.ToString());
Console.WriteLine(strBuilder.ToString());

Step 5: Run the application

You can add different kinds of validators or even write your own custom validator, but that's something for another blog post.