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Setting Verification Attributes on Properties

Printed From: IdeaBlade
Category: DevForce
Forum Name: DevForce 2009
Forum Discription: For .NET 3.5
URL: http://www.ideablade.com/forum/forum_posts.asp?TID=1412
Printed Date: 05-Apr-2025 at 8:48am


Topic: Setting Verification Attributes on Properties
Posted By: philcockfield
Subject: Setting Verification Attributes on Properties
Date Posted: 04-Aug-2009 at 1:11pm
Wow, there's a lot in the Verification engine. After reading through the Developer Manual I confused on this point:

There is lots of discussion about the Verifier attributes - and examples of these attributes on the properties in the generated class (.Designer.cs).

But that is re-generated everytime the ObjectMapper runs.

I can't see how to get these attributes onto the properties in a safe place.

I'm sure I'm missing something simple here. Any help?
Also, are there some concise code examples of this in action within a project? If so where. The learning resources just include the chapter in the Dev Manual and the PPT.

Thanks.


Replies:
Posted By: Waxman
Date Posted: 30-Oct-2009 at 4:58am
This is exactly my experience and question as well:
 
How do you apply (custom) property verifier attributes to your auto-generated business object properties?
For example, what's the simplest way to apply a regex verifier to a mapped string property?
What's the simplest way to apply a custom verifier to a mapped property?
 
Thanks,
Terry

Posted By: GregD
Date Posted: 30-Oct-2009 at 1:16pm
You can add verifiers using code as illustrated in the Silverlight, WPF, and WinForm code samples in the Validation section of the Learning Resources.

You can add attributed verifiers to generated properties in a metadata "buddy class" for your business class.  Below, I've added the buddy class into the same file (and namespace statement block) as the developer partial class.

The developer partial class needs to be marked with the MetadataType attribute to name the buddy class that contains the additional metadata.


...
using IbVal = IdeaBlade.Validation;
using DataAnnot = System.ComponentModel.DataAnnotations;

namespace DomainModel {
  [DataAnnot.MetadataType(typeof(EmployeeMetadata))]
  public partial class Employee  {

  ...

  }

  /// <summary>
  /// The buddy class for Employee.
  /// </summary>
  public static class EmployeeMetadata {

    /// <summary>
    /// Override city to make it required.
    /// </summary>
    [IbVal.RequiredValueVerifier()]
    public static string City;

    /// <summary>
    /// Restrict the string length more than in the generated verifier
    /// </summary>
    [IbVal.StringLengthVerifier(MaxValue = 10, IsRequired = true)]
    public static string FirstName;
  }
}
 

Posted By: Waxman
Date Posted: 30-Oct-2009 at 3:00pm

Thanks for the reply - this is exactly what I needed.  However, your suggestion doesn't seem to work for me.  It would probably help considerably if I knew what code samples you were talking about.  When I look in my 'C:\Program Files\IdeaBlade DevForce\Learning Resources\060_Validation' directory, all I see are three files:

- Ch080_Validation Through Verification.pdf
- Slides_Verification.pdf
- Slides_Verification.ppt
 
Should I be seeing something else?  Are you talking about a different place for code samples, like the website?  (Can't seem to find anything there either.)
 
At any rate, there seems to be an issue with the code you wrote above.  When I try to do what you did, I get a compiler error, because the verifier attributes can only be applied to properties and they are being applied to fields in your example.  Should they be properties?  If so, I tried automatic properties, and that didn't seem to work.  Not sure what I'm doing wrong.  Seem to be getting thwarted at every turn.
 
Thanks for the help,
Terry
 
P.S. Here's the code I'm using, if it helps at all:
 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.ComponentModel;

using System.ComponentModel.DataAnnotations;

using IdeaBlade.EntityModel;

using IdeaBlade.Validation;

using ProModel.Extensions;

namespace ProModel.Eps.ObjectModel.DevForce

{

[MetadataType(typeof(UserAccountMetadata))]

public partial class UserAccount

{

...
}

public static class UserAccountMetadata

{

[RequiredValueVerifier()]

public static string EmailAddress { get; set; }

}

}

Posted By: GregD
Date Posted: 03-Nov-2009 at 11:25am
What version are you running? The validation folder is currently named 070_Validation, and it contains a Samples folder that in turn contains folders with Winforms, WPF, and Silverlight code solutions that implement validation.

However, all of those except the Silverlight solution have been there for a pretty good while, so maybe something happened with your installation?

Version difference may explain the compile problems, too.

Posted By: Waxman
Date Posted: 04-Nov-2009 at 7:05am
You're right - I'm a couple of versions behind.  I've gotten permission to upgrade and the metadata stuff work fine now.  Cool!  However, now, I don't have any code samples.  I uninstalled my previous version (5.2.1.0) and after installing the new version (5.2.3.1), I don't even have a Learning Resources folder.  Not sure what going on.  Thanks for the help, though.
 
Terry

Posted By: GregD
Date Posted: 04-Nov-2009 at 11:29am
The LearningResources get installed different places depending on what OS you're using. If you're using Windows XP they should still be under C:\Program Files\IdeaBlade DevForce.  But wherever they get installed, you should be able to get to them via the IdeaBlade DevForce\Documentation\Learning Resources option on the Windows Start menu.

It is also possible to elect not to install them when you install the product, but I guess you'd know if you'd done that.

Posted By: jon
Date Posted: 14-Feb-2010 at 8:57pm
It is really a very good Experience to know that how to set verification attribute on Properties. As I know An attribute is a specification that defines a property of an object, element, or file. An attribute of an object usually consists of a name and a value; of an element, a type or class name; of a file, a name and extension.



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