One Procedure, Any Type

One Procedure, Any Type

Your team's audit log helper receives event payloads from all over the system — a customer record here, an amount there, sometimes just a flag. The payload arrives as a Variant, and your job is to render whatever is inside into one stable, machine-readable log line. A Variant will happily hold almost anything; the catch is that you must find out what it holds before you can safely convert it, and the type probes are not as innocent as they look.

Requirements

Create a codeunit named "Variant Formatter" with two public procedures:

procedure FormatValue(Value: Variant): Text
procedure TryFormatValue(Value: Variant; var FormattedValue: Text): Boolean

FormatValue inspects the Variant with its type probes (IsRecord, IsBoolean, IsGuid, IsOption, IsInteger, IsDecimal, IsDate, IsCode, IsText) and returns the payload in the canonical shape <type name>: <payload> — type name, colon, one space, then the payload rendered as follows:

• Record (any table): Record: followed by the table's name — a Customer record gives Record: Customer.
• Boolean: Boolean: true or Boolean: false — lowercase, never Yes/No.
• Guid: Guid: followed by the default AL rendering of a Guid — uppercase hex wrapped in braces, like Guid: {6B29FC40-CA47-1067-B31D-00DD010662DA}.
• Option: Option: followed by the value's zero-based position among the option's members, as plain digits — the third member gives Option: 2, not its name.
• Integer: Integer: followed by plain digits, with a leading minus for negative values.
• Decimal: Decimal: followed by the number with a dot as the decimal separator and no thousands separators, whatever the server's regional settings — Decimal: 1234567.5, never 1.234.567,5.
• Date: Date: followed by the date as yyyy-mm-dd — Date: 2026-04-07.
• Code: Code: followed by the stored value (Code values are stored uppercased, so that is what comes back).
• Text: Text: followed by the payload exactly as it was passed in — no trimming, no case changes.
• Anything else (Time, DateTime, Char, BigInteger, …): raise an error with the exact message Unsupported value type.

TryFormatValue is the companion for callers that must never crash:

• For a supported payload it sets FormattedValue to exactly what FormatValue would return and returns true.
• For an unsupported payload it returns false and sets FormattedValue to empty text — clearing whatever the variable held before the call — and it never raises an error.

Two warnings, because both failure modes are invisible until run time:

• The probes are not guaranteed to be mutually exclusive: a Code payload can also answer true to IsText, and an Option payload is integer-backed and can also answer true to IsInteger. A chain that asks the general question before the specific one sends the value down the wrong branch and produces the wrong tag.
• The plain one-argument Format obeys the server's regional settings for dates and decimals — a solution that relies on it can look right on your machine and still fail on the grading container. The canonical shapes above are fixed.

Pick object IDs in the range 50100–50199, and reference other objects by name, never by ID.

What the tests check

The tests call FormatValue with one Variant per supported type and compare the returned text exactly — note the colon-space separator, the lowercase booleans, the yyyy-mm-dd date shape, and the dot decimal separator with no thousands separators. Integer, decimal, text, guid, and date inputs are randomly generated, so the payload must really be converted, not recognized. A randomly generated lowercase Text payload must come back byte-for-byte, while a Code payload assigned from randomly generated lowercase text must come back uppercased as stored; option payloads are graded with two differently shaped option lists and two different member positions, so the zero-based number must be read from the value; records are graded with two different tables, so the table name must be read, not hardcoded. One test passes a Time value and expects FormatValue to fail with the exact message Unsupported value type. — the entire message is compared, period included; two more drive TryFormatValue — a supported payload (a negative integer, so the leading minus is graded too) must yield true plus the formatted text, and a DateTime payload must yield false with FormattedValue cleared to empty even though the variable held leftover content before the call.

Learn More

• Variant data type — the full catalog of Is<Type> probes available on a Variant.
• Formatting values, dates, and time — the standard format numbers, including the culture-invariant XML format.
• RecordRef.GetTable method — turning a record payload into something you can ask for its table name.
• Option data type — why option values are integer-backed.