Validation Application Block

New Post: Validate duplicate business key

AhmedSoliman — Sun, 24 Aug 2008 18:31:31 GMT

It is first time to use validation block and I succeeded to configure it. Mainly I need validation block for validating duplicate business key, for example: I need to validate username not exist in my database before . so I need the best way to do that considering the following:

- Asp.net application .net 3.5

- Business objects are LINQ classes ( I prefer these classes to be clean from any extra methods or attributes)

- I am using xml rule set

- For asp.net integration I am use PropertyProxyValidator

New Post: ValueConvert problematic

Biergarten — Thu, 21 Aug 2008 14:52:48 GMT

A good question. I have the same problem, but with an 'Int32' property.

I want it to be between 0 and 100000 or empty. And what i want is a error message like:

"The property should be an integer between 0 and 100000",

whatever they enter, for example:

"wkje"

"1.2"

"230403948574734"

"-2343"

Created Issue: Validator for XML data

praveenkrsharma — Tue, 10 Jun 2008 21:00:34 GMT

I require to validate XMLElement type Class member(Property or filed).

Which valdator i should use.

NEW POST: VAB and inherited classes

jacdevos — Wed, 12 Mar 2008 14:39:03 GMT

Validation.Validate(p) uses GENERICS to build the validator (this is similar to calling Validation.Validate<Person>(p)).

The solution is to use REFLECTION to create the validator, like this:
Istead of:
ValidationResults res = Validation.Validate(p);
Use this:
Validator entityValidator = ValidationFactory.CreateValidator(this.GetType());
ValidationResults res = entityValidator.Validate(p);

NEW POST: Validation Block Evaluation Questions

noeleee — Fri, 25 Jan 2008 19:58:34 GMT

Hey Everyone,

I have some questions about the Validation Block.

*I read there are some “quirks” with Enterprise Library 3.1 Validation Block. What are they?

*I am evaluating the v3.1 Validation Block for a WCF project based on .NET 3.5. Has anyone used it with the .NET 3.5 Framework? Have you had any issues? Do you see the lack of integration with 2008 as a major problem?

*Is a version that targets .NET 3.5/VS 2008 schedule for release? When?

*Does the Validation Block provide a mechanism to code the validation failure? For example, if a certain validation error should be associated with a particular control in the client, can I code that error with “0001” or GUID, etc.? Perhaps I would use the Key or the Tag property in the ValidationDetail?

Thanks very much!

Noel

NEW POST: VAB and inherited classes

phrozen — Wed, 16 Jan 2008 10:01:51 GMT

For example I use following classes:

public class Person
{
private string _Name;

public string Name
{
get { return _Name; }
set { _Name = value; }
}
}

public class Employee : Person
{
private string _Department;

StringLengthValidator(1,99)
public string Department
{
get { return _Department; }
set { _Department = value; }
}
}

And I want to validate a Person

Employee e = new Employee();
e.Name = "John";
e.Department = "";
Person p = e;
ValidationResults res = Validation.Validate(p);

the result is valid although the Department is empty.

How can I pass a base class and validate a possible sub-class?

Source code checked in

andysal — Sun, 06 Jan 2008 09:35:30 GMT

Source code checked in

andysal — Sun, 06 Jan 2008 09:33:32 GMT

Source code checked in

andysal — Sun, 06 Jan 2008 09:27:59 GMT

NEW POST: Is it possible to 'change' the location of the XML Rule sets?

nonnb — Thu, 27 Dec 2007 08:04:45 GMT

Hi & Happy Holidays

We have a Smart Client business app, and, would like to keep the validation rules on the server side of the SOA.

However, as a performance benefit (i.e. save an unnecessary server round trip), and user experience benefit, the "on the fly" validation capability of VAB / Validation Provider / ErrorProvider on the UI works very well, and we would like to get the benefit of this as well.

Although we can duplicate the rule configs on both Client and Server, it would be 'nicer' if we can keep to the one common set, i.e. we would like to keep our entity validation rules in our Server app.config, but would like to expose a rules 'service' allowing clients to retrieve these rules (and cache them) for the purpose of 'early / on the fly' validation.

Which brings the question : Is there a simple way to dynamically set the Validation "rule" store (on the client) to a location other than app.config, or will we need to hack the file?

This is probably a common scenario with a Smart Client / VAB combination?

Thanks in Advance

Regards

Stuart

NEW POST: Validating Arguments To Constructors

colin_jack — Wed, 07 Nov 2007 21:25:06 GMT

I'd like to be able to use your style of validation for arguments to constructors. Is this possible and even better is there any way I can find out whether it is possible to construct and object and if not why not, I'm thinking of something like this:

Title title = ...;
string firstName = ...;

ValidationResults r = Validation.ValidateConstruction<typeof(CustomerName)>(title, firstName);

This method would look at the attributes applied to the constructor and if it finds any would evaluate them against the passed in data (with the order of the arguments to the ValidateConstruction method being in the same order as the arguments to the constructor). Thus if we had an attribute on the constructor that required the first argument to be non-null then we'd get a validation-result failure if "title" was null.

Is this possible or do you think it would be easy for me to add?

NEW POST: VAB ignores Inheritance when configuring rules in config file

Shababhussain — Wed, 22 Aug 2007 19:12:41 GMT

I have an interesting situation and am getting confusing results.

Scenario:
I have a class hierarchy with base class and several sub-classes. I would like to apply validation rules at the base class for common fields and have sub-classes inherit those rules. I can do this by applying attributes to the fields in base class. However, this does not work when I apply the rules on the base type using the web.config and not the attributes. VAB does not respect inheritance when reading rules from the config file.

Is this "working as desgined"? Is there any workaround for this other then just hard coding my validation rules via attributes in the base class?

Thanks,

--Shabab

NEW POST: Business Object validation - with Validation Application Block

eug — Fri, 27 Jul 2007 09:12:11 GMT

My question: the validation application block (VAB) is not a perfect match for our requirements but can be amended to fit, so is it the right solution to go with?

VAB benefits: UI validation, business object validation, central place to store rules, etc.
negatives: rules stored in xml, rules cant be edited at runtime.

My scenario in nutshell : I have quite a few Customer business objects. Each customer has a similar (yet different) set of rules to be validated against, but the rules change dynamically depending on which the month of the year it is, or on the Customer's countryID, for instance. We will need to create many different rulesets (one for each scenario), for example CustomerA is subject to Ruleset1,2 and 3, but if CustomerA had a different countryID then RuleSets1 and 4 apply instead. We also want the customer-admin to be able to log into an admin section on our web application and manage their rules (or some of the rules), i.e. enable/disable rules and change the Range values of a range validator for example. In the past we have used customer specific xml files to contain certain config settings (similar to xml rules), but managing the file configuration turned into a nightmare and is now strongly opposed where I work.

My proposed solution (A) : use the Validation block, with this many rules we can really benefit from the features of VAB. The problem is that in order to satisfy all the different rules we will end up with loads of different rulesets and configuration files (which is not what we want) and changing the rules will require a developer with xml knowledge or access to the Enterprise Library Configuration tool - which is not ideal when we want the customer to be able to manage rules. (we could perhaps make this work by writing some code to manage and edit the customer xml files?).

My proposed solution (B) : use the Validation block along with SqlConfiguration to store the rules in a sql db, getting away from config files in the file system. The problem here is that the sqlconfiguration simply dumps a long serialised xml string into a single database column (ntext field type) with no normalisation at all. With large rulesets this is perhaps even worse than managing xml files? Provided that the ntext field can handle all our rules this solution might work, we could then extract the rules-xml from the DB and create some code and an interface in the web application for editing the rules.

Poposed Solution (C) : take solution B and amend the sqlconfiguration stored procedures to store and retrieve the rules in a better way. The procs will have to take different sets of parameters and we will have to create our own rules and constraints tables and write some code to insert and retrieve the rule settings, and to include these rules in validation. This might end up being a lot of work. Well it’s not that much work but we will probably end up writing our own validation engine.

Solution B will probably work best, using Enterprise Library Configuration tool initially to set up the rulesets, storing the rules in the database; and then for editing the rules we create a section in the web application that will read (deserialise) the xml rulesets from the database and allow authenticated customers to edit and save the rules back into the database.

Has anyone used the validation block to such extent? Please reply to let us know the recommended approach.

NEW POST: Dynamic validation messages accessed from markup/code behind

aaroncat — Wed, 11 Jul 2007 11:59:00 GMT

Hi there,

I am doing some research into the Validation Application Block to assess its appropriateness for a particular ASP.NET application.
So far it looks great and I would like to thank the P&P team for another great block.

The one thing that is holding me back from giving the all clear to use the VAB is that the application we are developing requires qualified error messages. For example, on some pages we may have repeated form fields for two instances of a particular object, in one instance there will be two address blocks, one for residence and the other for correspondence/mail. As they will be saving to the same business object (i.e. Address.cs) I require a method of qualifying the validation messages in order to distinguish between two fields.
i.e.

1. * The postcode you have entered is invalid.

The postcode you have entered is invalid.

2. * The home postcode you have entered is invalid

The correspondence postcode you have entered is invalid

1 is what would occur from normal use of the VAB as I have encountered in my research so far, 2 is the desired behaviour.

I was looking at extending the PropertyProxyValidator class and allowing the setting of a QaulifierString in the markup (or code behind if there was a need for dynamic messages).

I am interested to hear if others have encountered this and resolved it or if there is something already implemented that I have missed so far.

Cheers

Aaron

NEW POST: VAB and RegExValidator - How can I do a "does contain"

bullman — Mon, 09 Jul 2007 21:41:16 GMT

By default, the RegExValidator flag items when the data to be validated does not contain the given pattern. What If i want to flag the data only when it does contain the pattern.

For example, I have a url field that I use elsewhere in my applicaton programatically. I dont want people adding http:// to the field, becuase I will add that later. So I only want the validator to flag data when it does contain 'http://'.

NEW POST: ValueConvert problematic

Hermans — Thu, 31 May 2007 15:25:33 GMT

We are planning to use the VAB with a Windows user control bound to a business object.
When using a property of type 'Int16' of the business object it turns out we cannot handle using attributes only, the following errors:
- empty field in the user control
- Int32 value (>Int16) in the user control
- only Int16 input works correctly

- string value in the user control -> in this case the validator of the VAB gives an error message, but we cannot customize it via attributes

When we have to hande all input errors in the ValueConvert event of the validator provider, what then are the benefits of the VAB left?

NEW POST: Validation Application Block - expose to UI

ksfrahman — Mon, 28 May 2007 06:03:48 GMT

Hi,

I like to access the validations done by an object from the UI layer (ex : webpage). This is because, for validations like StringLengthValidator, the webpage can check the available validations with an object and set the maxlength property of the respective textbbox.

I am able to get the attribute associated with a property using reflection. but could not get the values with that (ex: minlength and maxlength).

Please help. thanks in advance.

Project Management Forum: Validation Application Block in EntLib v3

tomhollander — Wed, 01 Nov 2006 23:54:58 GMT

Hi - I'm the Product Manager for Enterprise Library in the Microsoft patterns & practices team. We've already started work on our own Validation Applciation Block for Enterprise Library v3. We recently found out about this project, and I thought it would be good to sync up to see if there are any ways we can align or work together. If you can contact me at tom.hollander at microsoft.com, we can discuss this offline. thanks! Tom Hollander

Developer Forum: Contextual validation

MarioDuz — Mon, 23 Oct 2006 16:45:53 GMT

First of all, I'm sorry for my poor english! :-) I want to talk about a small doubt: why VAB is designed for a single validation context? I try to explain it better... Maybe that, in some cases, a MaxLenght validation must be set due to database capabilities or also to DAL requisites. I.e. maybe that a Product.Description property value can be smaller than 255 charachters if the user works with an Access DB; otherwise if the DB is SQLServer, MaxValue maybe greater. It is wrong to think on a contextual validation rule module (plug-in or similar) separated from entities? Thx!

User Forum: Fixed bug

lucaminudel — Fri, 13 Oct 2006 20:48:28 GMT

maybe there is a bug in current Change Set: 8157 in NullableAttribute.GetRule() is protected override ValidationRule GetRule() { return new NullableRule(false); } while it should be protected override ValidationRule GetRule() { return new NullableRule(value); }