Product Review
Professional Validation and More
Reviewer: Anand Narayanaswamy

Pricing & Licensing

Web Server License: $50
Site License: $250
Redistribution License: $500
VAM’s Source Code: $250
(All prices in US Dollars)

About the Author

Anand Narayanaswamy, a Microsoft Most Valuable Professional (MVP) in Visual C# is an independent writer, web developer and technical consultant based in Trivandrum, India. Anand runs learnXpress.com and specializes in ASP, ASP.NET, C#, Visual Basic .NET and Visual Basic 6.0 and in the development of courseware, technical articles, documentation, and reviews of products and books. He is available for writing documentations, help files, product reviews, editing and development jobs. Reach him at ananddotnet@yahoo.co.in 

Every website captures information from its users via Forms. There may be different forms for contacting the webmaster, putting feedback about the site, registration and login. A web developer should not only design the forms but also implement proper rules for checking the accuracy of the data entered by the users before submitting it to the server database or via e-mail. In developer’s parlance, this process is called as Validation. Prior to .NET, developers employed Java Scripts and VBScripts for validating the entries. The error messages can be displayed with the help of message boxes. The main problem associated with these scripting languages is that they are some times very complicated and also they are browser dependant.

With the evolution of .NET, the process of validating the data has become much easier for developers. .NET provides five useful controls namely RequiredFieldValidator, CustomValidator, CompareValidator, RangeValidator and RegularExpressionValidator. With the help of these controls, developers can quickly implement validation for their WebPages. Even though these controls helped developers a lot, still many of them were not satisfied and they demanded more such controls. This is because they have to write complex set of code with CustomValidator control using JavaScript in order to achieve various tasks. PeterBlum’s Professional Validation and More (VAM) is a replacement to Microsoft’s validation. From my point of view, this is the only second generation solution available for performing validations.

The product contains 16 validation controls with support for new functionalities like text length, the state of a checkbox or radio button, how many items are selected in a CheckBoxList or multi-selection ListBox, and which radiobutton is selected in a RadioButtonList. VAM supports non IE browsers (IE Mac, Netscape 6+ (all platforms), Opera 7, and Apple Safari) on the client-side while Microsoft’s Validation Controls doesn’t. This feature makes the product not only powerful but also users with different browsers can view the content without any problems.

One of the other interesting features of VAM is that of Validation Groups. Using the group, you can connect a submit button to a specific set of group of validation controls. This can be achieved by assigning the same string in the Group property of the validators and VAM’s own submit buttons. With VAM’s MultiConditionValidator, you can merge several validation controls and display a common message. One common use for this functionality is to merge the RequiredFieldValidator with another. You cannot perform these kinds of functionalities with the Microsoft’s Validation Controls.

VAM provides a cute feature for formatting error messages. You can add an image before an error message. You can even use an image with a tooltip or an alert box that shows the error message. These formatting techniques will save lot of screen space as well. One of the features of this product which I liked very much is that VAM supports the usage of tokens. These tokens will be replaced by the appropriate values at runtime. For example, you can display a message like as shown below:

Please enter a value greater than {MINIMUM} in {LABEL}

You can also display a blinking error message using VAM. The product also provides functionalities for Localization. This means, you can provide different error message strings for different languages. VAM offers specialized TextBoxes like the IntegerTextBox, DecimalTextBox, and CurrencyTextBox. The ValidationSummary control shipped with VAM supports hyperlinks on each error message. The product monitors a WebForm control with the help of FieldStateController. The main feature of the FieldStateController is to change the appearance of your web form on the client-side as the user performs several tasks, like marking a checkbox can make another control visible, enabled, change its style sheet or a URL to an image and much more.

The installation process went off very smoothly. The vendor will supply a special license file via e-mail which you have to apply appropriately in order to work with VAM. In addition to the installation of the core setup file which you have downloaded, you have to also install ASP.NET Design Mode Extender (ADME) on your system. VAM uses the extender for performing many different operations. You can know more details about ADME from the User’s Manual which ships with the product. The User’s Manual also provides a complete list of all features of VAM. I must say that the manual is very elaborate and a very useful companion for the product. Unlike many other products the documentation is in PDF format. The manual explains the usage of each and every validation controls along with the relevant source codes. I experienced certain difficulties to work with this product initially. But I sorted out the problems by going through their User’s Manual. The vendor provides quick support by e-mail. They also clarified all my doubts regarding the product very positively. For more information about the product, visit http://www.PeterBlum.com/VAM/Home.aspx