Resolving "InvalidCastException" for Custom Boolean Fields in Acumatica
Introduction
While rare, the InvalidCastException: Specified cast is not valid error can occur in Acumatica when working with custom Boolean fields on any screen — such as Sales Order — if specific scenarios, like Copy and Paste, introduce unexpected data formats. This can disrupt workflows, especially when a Field_Updating event handler is implemented for the custom field.
In this article, I’ll explain the problem, demonstrate a fix, and include an example of the DAC definition for a custom Boolean field.
Understanding the Issue
Acumatica’s Copy and Paste functionality may pass values for fields as strings (e.g., "True" or "False") even when the field is defined as a bool in the DAC. When the Field_Updating event handler attempts to directly cast e.NewValue to a Boolean, this mismatch causes an InvalidCastException.
When Does This Happen?
● Custom Boolean fields on any screen (e.g., Sales Order).
● A Field_Updating event handler is defined for the field.
● The field's value is passed as a string instead of the expected Boolean during Copy and Paste or API operations.
Solution: Safe Casting of e.NewValue
To prevent this error, you must safely cast e.NewValue to a Boolean. Below is the complete implementation:
DAC Code Example for the Custom Field
using PX.Data;
namespace Customization
{
public class SomeEntityExt : PXCacheExtension<PX.Objects.AR.SomeEntity>
{
[PXDBBool]
[PXDefault(false)]
[PXUIField(DisplayName = "Custom Boolean Field")]
public bool? UsrCustomBooleanField { get; set; }
public abstract class usrCustomBooleanField : PX.Data.BQL.BqlBool.Field<usrCustomBooleanField> { }
}
}
In this example:
● The field UsrCustomBooleanField is a custom Boolean field added to an entity (e.g., SomeEntity).
● The [PXDBBool] attribute ensures the value is stored as a Boolean in the database.
● The [PXDefault(false)] attribute sets the default value to false.
Field_Updating Event Handler Example
How It Works
- Type Checking and Safe Conversion:
○ If e.NewValue is a Boolean (bool), the code directly assigns it to customFieldValue.
○ If e.NewValue is a string, bool.TryParse safely converts it to a Boolean.
- Default Handling:
○ If e.NewValue is null or cannot be converted, the value defaults to false.
- Logic Execution:
○ Custom logic can be applied based on the Boolean value of the field.
Why This Solution Works
● Handles All Scenarios: Ensures the code functions correctly regardless of whether e.NewValue is passed as a Boolean or string.
● Prevents Runtime Errors: Eliminates the risk of InvalidCastException by safely handling type mismatches.
● Reusable Pattern: This method can be applied to any field where e.NewValue might have inconsistent formats.
Key Takeaways
● Understand the Cause: The InvalidCastException occurs because Acumatica may pass unexpected data types (e.g., strings) during operations like Copy and Paste.
● Implement Safe Casting: Always check the type of e.NewValue and convert it safely to the expected type.
● Plan for Edge Cases: Test your customizations with scenarios like Copy and Paste, as well as API integrations.
By using this approach, you can ensure the robustness of your customizations across various Acumatica screens. If you've faced similar challenges or have additional tips, share them in the comments below!