Function: GETITEMVALUE

Description
GETITEMVALUE returns the value of an attribute or calculated value from another item. It’s commonly used with WHERE and IF to reference values across items.

Two overloads exist:
- GETITEMVALUE(itemIdentifier, codeValue)
- GETITEMVALUE(itemIdentifier, codeValue, type)

Syntax
GETITEMVALUE(itemIdentifier, codeValue)
GETITEMVALUE(itemIdentifier, codeValue, type)

Parameters
- itemIdentifier — the identifier for the source item whose value you want. Defaults to the item's name if type is not specified; can be an internal or external ID when type indicates so.
- codeValue — the attribute or calculated value code to return (e.g., "cost", "RAG Status").
- type (optional) — specifies how to interpret itemIdentifier: "name" (default), "Internal ID", or "External ID".

Return Value
Returns the data type defined for the referenced attribute/calculated value (NUMBER, DATE, TEXT, BOOLEAN, ARRAY, etc.). The returned type is determined by how the target attribute/calculation is defined.

Examples

1) Return cost of "ITEM 1" to all items
Formula
GETITEMVALUE('ITEM 1', 'cost')
Result
Returns the cost value held by ITEM 1.

2) Return RAG Status using an internal ID
Formula
GETITEMVALUE(1001, 'RAG Status', 'Internal ID')
Result
Returns the RAG Status for the item with internal ID 1001.

3) Return cost via a reference attribute (Ref stores a target item name)
Table
Item(name) | Cost | Ref | Result
ITEM1      | 99   | ITEM2 | 100
ITEM2      | 100  | ITEM3 | 101
ITEM3      | 101  |       | ERROR (no ref)

Formula
GETITEMVALUE(Ref, 'Cost')
Result
Finds the item named in Ref and returns its Cost; where Ref is empty, returns error/null.

Notes
- Default lookup is by name; specify type when using internal/external IDs.
- GETITEMVALUE can return any type; ensure calling formula expects that type.
- When used on arrays or WHERE results, ensure the identifier resolves to a single item (or use GETITEMVALUES for multiple items).
- Missing or invalid identifiers may return NULL or an error depending on context.