Locale-Proof Evaluate and Format

Locale-Proof Evaluate and Format

Your extension exchanges documents with an external REST service. On your machine every payload was perfect; then the first Danish customer went live and the service started rejecting documents — amounts arrived as 1.234,56 and dates as 05-02-2026. Nothing in the code had changed: Format and Evaluate quietly follow the regional settings of the session they run in, and the customer's server doesn't speak your locale.

Your job is a conversion codeunit that writes and reads the same wire text on every server, whatever its regional settings.

Requirements

Create a codeunit named "Wire Format" with four public procedures:

procedure ToWireDecimal(Value: Decimal): Text
procedure ToWireDate(Value: Date): Text
procedure FromWireDecimal(WireText: Text; var Value: Decimal): Boolean
procedure FromWireDate(WireText: Text; var Value: Date): Boolean

Rules:

1. ToWireDecimal renders the value as culture-invariant wire text: a leading - for negative values, plain digits, and a dot . before any fractional part — never a group (thousand) separator, never a comma. 1234567.89 must come out as 1234567.89 and -1234.5 as -1234.5.
2. ToWireDate renders the date as YYYY-MM-DD with zero-padded month and day: 3 February 2026 must come out as 2026-02-03. Only real (non-zero) dates are graded.
3. FromWireDecimal parses wire decimal text into Value and returns true. Text that is not in wire format returns false — that includes locale-formatted text such as 1,5 (a comma is never valid on the wire) as well as outright garbage. It must never raise an error, whatever the text contains.
4. FromWireDate does the same for YYYY-MM-DD dates: 2026-01-23 parses to 23 January 2026; text in any other shape returns false without raising an error.
5. Round trip: any text ToWireDecimal or ToWireDate produces must be accepted by the matching FromWire procedure and yield exactly the original value.
6. After a failed parse, the returned false is the only graded signal — whatever is left in the var parameter is not checked.

What the tests check

The ToWire procedures are compared against exact strings — note the dot, the leading minus and the zero padding. The FromWire procedures are fed valid wire text (which must parse to the exact value), locale-formatted text — comma decimals like 1,5 and day-first dates like 05-02-2026 (each must return false — not true, and not an error) — and garbage (which must return false). Two round-trip tests run on generated values, so hardcoding the examples won't pass.

Learn More

• Formatting values, dates, and time
• System.Format(Any [, Integer] [, Integer]) method
• Evaluate method
• Formatting decimal values in fields