Strategies for Validating CSLA Objects and Triggering Save in Blazor

[ecaldentey]

Hello,

I have a CSLA class called BusinessDeal whose graph is complex because it has many child classes such as BusinessDealAnnex and, in turn, BusinessDealAnnexClient. In a Blazor page, I manage the class, and to manage the list of children (BusinessDealAnnex) and grandchildren (BusinessDealAnnexClient), I use components on the main page. On the main page, I have buttons that allow saving changes made to the BusinessDeal object and its children to the database.

But I want to enable the Save button when at least the required fields for the root object and its children have information. Although the required properties are defined with their attributes indicating that they are required and the minimum lengths for string properties, the class remains valid even when those fields have not been filled.

Here is an example of the definition of some properties:

[Display(Name = "BIZDEAL_ID")]
[Required(ErrorMessage = "The BizdealId field is required")]
public static readonly PropertyInfo BizdealIdProperty = RegisterProperty(nameof(BizdealId));
public Decimal BizdealId
{
get => GetProperty(BizdealIdProperty);
set => SetProperty(BizdealIdProperty, value);
}

[Display(Name = "BIZDEAL_TYPE")]
[Required(ErrorMessage = "The BizdealType field is required")]
public static readonly PropertyInfo BizdealTypeProperty = RegisterProperty(nameof(BizdealType));
public Int16 BizdealType
{
get => GetProperty(BizdealTypeProperty);
set => SetProperty(BizdealTypeProperty, value);
}

[Display(Name = "BIZDEAL_CODE")]
[Required(ErrorMessage = "The BizdealCode field is required")]
[StringLength(30, ErrorMessage = "The BIZDEAL_CODE field cannot exceed 30 characters")]
public static readonly PropertyInfo BizdealCodeProperty = RegisterProperty(nameof(BizdealCode));
public String BizdealCode
{
get => GetProperty(BizdealCodeProperty);
set => SetProperty(BizdealCodeProperty, value);
}

I need to do something additional for CSLA to detect that the conditions of the properties are not met and mark the object as invalid if the attributes are not satisfied.

What is the best way in the graphical interface to validate that the object is complete in order to enable the save button?

Any help will be appreciated.

Thanks

[rockfordlhotka]

By default, rules don't run in the data portal create or createchild operation methods. This is for performance reasons.

In your case (and in many cases) it is desirable to run rules in those operations, because otherwise things like Required don't start out making the new objects invalid.

Just call await BusinessRules.CheckRulesAsync() at the bottom of all your create and createchild operation methods.

[ecaldentey]

Hello,

These are some of the properties defined in my class, where there are numeric properties that should be valid when the value is greater than zero. When the object is created, the value is zero, and I assume the validation considers it a valid value. However, there are text properties like the BizdealCode property.

[Display(Name = "PROVIDER_ID")]
[Required(ErrorMessage = "The field ProviderId is required")]
public static readonly PropertyInfo ProviderIdProperty = RegisterProperty(nameof(ProviderId));
public Decimal ProviderId
{
get => GetProperty(ProviderIdProperty);
set => SetProperty(ProviderIdProperty, value);
}

[Display(Name = "BIZDEAL_ID")]
[Required(ErrorMessage = "The field BizdealId is required")]
public static readonly PropertyInfo BizdealIdProperty = RegisterProperty(nameof(BizdealId));
public Decimal BizdealId
{
get => GetProperty(BizdealIdProperty);
set => SetProperty(BizdealIdProperty, value);
}

[Display(Name = "BIZDEAL_TYPE")]
[Required(ErrorMessage = "The field BizdealType is required")]
public static readonly PropertyInfo BizdealTypeProperty = RegisterProperty(nameof(BizdealType));
public Int16 BizdealType
{
get => GetProperty(BizdealTypeProperty);
set => SetProperty(BizdealTypeProperty, value);
}

[Display(Name = "BIZDEAL_CODE")]
[Required(ErrorMessage = "The field BizdealCode is required")]
[StringLength(30, ErrorMessage = "The field BIZDEAL_CODE cannot have more than 30 characters")]
public static readonly PropertyInfo BizdealCodeProperty = RegisterProperty(nameof(BizdealCode));
public String BizdealCode
{
get => GetProperty(BizdealCodeProperty);
set => SetProperty(BizdealCodeProperty, value);
}

[Display(Name = "CONTRACT_NAME")]
[Required(ErrorMessage = "The field ContractName is required")]
[StringLength(255, ErrorMessage = "The field CONTRACT_NAME cannot have more than 255 characters")]
public static readonly PropertyInfo ContractNameProperty = RegisterProperty(nameof(ContractName));
public String ContractName
{
get => GetProperty(ContractNameProperty);
set => SetProperty(ContractNameProperty, value);
}

When creating the object as follows, CSLA always considers it valid even though the text fields are created as null.

[Create]
private void Create([Inject] IBizdealDal dal, [Inject] IChildDataPortal listBizdealAnnexs)
{
LoadProperty(BizdealIdProperty, dal.FetchId());

CreateChildList( listBizdealAnnexs);

BusinessRules.CheckRules();

bool isValid = this.IsValid;   **//isValid  is always true** 

}

What am I doing wrong?
Do I need to create specific CSLA rules? C# attributes alone are not enough?
To validate that the numeric properties equal to zero are invalid, do I need to create a C# validation or a CSLA rule?

[rockfordlhotka]

CSLA doesn't allow null string values, because Windows Forms data binding can't handle null values.

You should use the [Required] attribute or required rule from Csla.Rules.CommonRules (or a similar rule) to see if a string property actually has a non-null and non-empty value.

[ecaldentey]

Hello,

The BizdealCode property is indeed marked with the Required attribute; here is the definition:

[Display(Name = "BIZDEAL_CODE")]
[Required(ErrorMessage = "The field BizdealCode is required")]
[StringLength(30, ErrorMessage = "The field BIZDEAL_CODE cannot have more than 30 characters")]
public static readonly PropertyInfo BizdealCodeProperty = RegisterProperty(nameof(BizdealCode));
public String BizdealCode
{
get => GetProperty(BizdealCodeProperty);
set => SetProperty(BizdealCodeProperty, value);
}

However, when creating the object via the DataPortal and executing BusinessRules.CheckRules(), the class appears valid, even though the BizdealCode property has a null string. So I'm not sure what is happening, and the validation should indicate that the object is not valid.

What I want to do on my Blazor page is every time there is a change in the CSLA root class connected to a Csla.Blazor.ViewModel, or in any of its multiple children (the class graph is complex, with many children, grandchildren, etc.), check the validations to see if the object is valid, and if it is, enable the Save button that is on the Blazor page, something like calling BusinessRules.CheckRules() from the UI to determine if the object is valid.

Can this be done?

[ossendorf-at-hoelscher]

Do you override AddBusinessRules?
If yes, make sure to add base.AddBusinessRules() otherwise the data annotations are not checked.

[ecaldentey]

Hello @ossendorf-at-hoelscher ,

Thank you for your response regarding validation in CSLA. As I understand it, calling BusinessRules.CheckRules() should validate the object, and the property this.IsValid should accurately reflect the validation state.

However, I have a few questions about the implementation:

Override of AddBusinessRules: You mentioned that I need to ensure that base.AddBusinessRules() is called in my override of AddBusinessRules. My understanding is that if I do not call this base method, the validation attributes from Data Annotations will not be processed. However, if I'm not overriding the AddBusinessRules method in my class, will it still be called by default, and will the validation rules be evaluated?

Use of Data Annotations: I have properties that are decorated with Data Annotations attributes, but when I instantiate my CSLA object using the Create() method, it seems that the validations are still not applied, and this.IsValid remains true. Are there additional configurations I should consider to ensure that both business rules and validations work correctly?

[Display(Name = "BIZDEAL_CODE")]
[Required(ErrorMessage = "The field BizdealCode is required")]
[StringLength(30, ErrorMessage = "The field BIZDEAL_CODE cannot have more than 30 characters")]
public static readonly PropertyInfo BizdealCodeProperty = RegisterProperty(nameof(BizdealCode));
public String BizdealCode
{
get => GetProperty(BizdealCodeProperty);
set => SetProperty(BizdealCodeProperty, value);
}

Manual Checks: In case the validations do not apply even after ensuring that AddBusinessRules is correctly overridden, should I implement any manual checks or additional validations in my code to enforce these required properties?

Here is the code I’m currently working with for creating the object:

[Create]
private void Create([Inject] IBizdealDal dal, [Inject] IChildDataPortal listBizdealAnnexs)
{
LoadProperty(BizdealIdProperty, dal.FetchId());

CreateChildList(listBizdealAnnexs);

BusinessRules.CheckRules();

bool isValid = this.IsValid; // isValid is always true

}

I would appreciate any further clarification or guidance on this topic, as ensuring that the objects are valid before proceeding is crucial.

Thank you in advance for your help!

[rockfordlhotka]

The way the CSLA rules engine works, is that rules are evaluated when:

1. A property is changed via the SetProperty helper in the set implementation
2. A property is dependent on a property that was set as per number 1
3. CheckRulesAsync or CheckRules are invoked (to run all rules or rules for a specific property)

If any of your rules are async, you must await the CheckRulesAsync method and must not use the CheckRules method.

---

If you aren't sure if the right rules are associated with your properties, you can write code in your business class to get the list of registered rules. This is available from the BusinessRules object: BusinessRules.GetRuleDescriptions.