bcquality/custom/knowledge/architecture/pages-must-not-contain-business-logic.md

bc-version	domain	keywords	technologies	countries	application-area
all	architecture	page trigger onaction modify codeunit logic	al	w1	all

Description

In CURABIS codebases, pages are pure presentation. Business logic, calculations, validations, and record modifications belong in codeunits — not in page triggers or actions. This is stricter than the general BC guidance and applies to all CURABIS PTE apps.

A page procedure that calculates a value and assigns it to a field, calls Rec.Modify() directly, or implements business rules is an architecture violation even if it compiles.

Exceptions:

• Setup pages may read and write their own setup record directly.
• The designated "Run Conversion" page may call the conversion codeunit directly.

Anti Pattern

// WRONG: calculation and Modify in a page action
trigger OnAction()
begin
    Rec."Total Amount" := Rec.Quantity * Rec."Unit Price";
    Rec."VAT Amount" := Rec."Total Amount" * 0.25;
    Rec.Modify();
end;

// WRONG: validation logic in page trigger
trigger OnValidate()
begin
    if Rec.Quantity < 0 then
        Error('Quantity cannot be negative');
    Rec."Total Amount" := Rec.Quantity * Rec."Unit Price";
end;

Best Practice

// CORRECT: page delegates to codeunit
trigger OnAction()
begin
    SVManagement.RecalculateLine(Rec);
end;

// CORRECT: validation belongs in table or codeunit
trigger OnValidate()
begin
    SVManagement.ValidateAndRecalculate(Rec);
end;

The codeunit owns the logic. The page owns the presentation.