How can I reject changes made to a child list based on status of a parent object?
I have a Root object like this:
Partial Public Class Contrato
Inherits BusinessBase(Of Contrato)
(Some properties Here including ContratoId Of Type System.Int64 (primary key) and TipoContratoId of Type System.Int32)
Then a Child member property like this:
Private Shared ReadOnly _CuotasMemberProperty As PropertyInfo(Of CuotaList) =
RegisterProperty(Of CuotaList)(Function(p As Contrato) p.Cuotas,
Public ReadOnly Property Cuotas() As CuotaList
Dim cancel As Boolean = False
If Not cancel Then
If Not (FieldManager.FieldExists(_CuotasMemberProperty)) Then
Dim criteria As New MultiCob.Business.CuotaCriteria()
criteria.ContratoId = ContratoId
If (Not MultiCob.Business.CuotaList.Exists(criteria)) Then
How could I prevent changes made to "Cuotas" based on Current "TipoContratoId" value ?
There are two things to consider.
First, validation doesn't prevent things from happening. Validation reports that a change was invalid. So you could maybe solve your problem by using a validation rule that marks the child object's property as invalid based on the value of the parent object's property.
Second, authorization can prevent things from happening. An authorization rule can dynamically make a property read-only. So you could maybe solve your problem by attaching an authorization rule to the child property's CanWrite action that disables writing to the property based on the value of the parent object's property.
Either of these rules would go into the editable child contained by the CuotaList collection.
Thank you for your time. I'll go with the second option, this is the right path...
But, I'm still confused about how this should be implemented. You said:
"... you could maybe solve your problem by attaching an authorization rule to the child property's CanWrite action..."
And that makes me think that I Should :
1.- Create a new class inheriting AuthorizationRule
2.- Implement Execute Method to check for TipoContratoId property value and set HasPermission value accordingly.
3.- Attach a new instance of this Validation rule to my object "Contrato" like this (?) :
Note: ContratoPuedeEditarCuotasAuthorizationRule's constructor calls Base constructor like this:
Public Sub New(ByVal CuotasProperty As IPropertyInfo)
I've tried this before (and I will do it again if required) with no success. My custom authorization rules never gets invoked.
I'm I doing something wrong?
Now, the last line in your post you said:
"Either of these rules would go into the editable child contained by the CuotaList collection"
That's killing me... Do you mean that my custom AuthorizationRule should be attached to the ChildItem Object? (In this case "Cuota")
If so, how could I get the parent object's TipoContratoId property value in this context?
Thanks in advance!
Something like this:
private class CheckTipoContract : Csla.Rules.AuthorizationRule
protected override void Execute(Csla.Rules.AuthorizationContext context)
var target = (ProjectResourceEdit)context.Target;
var parent = (ProjectEdit)((ProjectResources)target.Parent).Parent;
if (parent.TipoContratold == 0)
context.HasPermission = false;
context.HasPermission = true;
This rule is in an editable child class. Notice how it sets the parent field by getting the Parent of its Parent. The immediate parent is a list, and the parent we want is the parent of the list. I think this is your scenario?
That's working fine, and now I realize what you were trying to acomplish. Even so, it doesn't fit perfectly into what I want to do since I need the whole collection of child items to be readonly based on this authorization rule, not just some child item's property.
Could you please point me the direction to do it?
I really appreciate your support, thanks again.
The way to make a collection "read-only" is to override the methods that occur in response to insert/move/clear/remove and to throw exceptions when they occur. But that doesn't prevent editing of existing child objects - for that you need those child objects to block editing of all their properties (like in my previous couple posts).
Yes!!!, that should work.
Thank you very much!
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