Transformation Behavior
A Third-Party Model maps each field from the Golden Model into the shape a destination expects. This page describes what a mapping does to a string value when you remove a literal prefix from it, and which kinds of expressions a mapping does not support.
Removing a literal prefix
Prefix removal strips one literal leading match from a string.
- It is a literal, not a pattern. The prefix you enter is matched exactly as typed, and matching is case-sensitive.
- It strips one match. Only the first occurrence at the very start of the value is removed. If the prefix appears again right after, that second copy stays.
- A string without the prefix passes through unchanged. If the value does not start with the prefix, you get the same string back. It is not an error.
- A value that is not a string is a visible mapping failure. A number, a true/false value, an object or an array is not passed through quietly. The mapping fails where you can see it.
- An empty prefix is refused when you save. You cannot save a prefix removal with nothing to remove.
Examples
With the prefix #:
| Input | Output |
|---|---|
#JW1191618 | JW1191618 |
A#B | A#B (unchanged — # is not at the start) |
##JW1191618 | #JW1191618 (only one # is removed) |
What a mapping does not support
A mapping reads one source value and writes one target field. These forms are not supported:
- Combining two or more source fields into one value.
- Joining values, or a value and a literal, into one output field.
- Custom functions.
- Regular-expression substitution.
- Field shorthand outside a filter. Naming a field directly, without a full path, works only inside a JSONPath filter. Everywhere else in a mapping, point to the value with a full path.
- Conditional expressions inside a mapping value. Conditional output is expressed with a derived field and its cases instead.
- Arithmetic in derived-case output. Each case in a derived field produces either a literal value or a value looked up directly from a path. A case does not calculate, so it cannot add, subtract, multiply or otherwise compute a result.
Related concepts
- Third-Party Model — where field mappings are declared.
- Golden Model — the canonical schema every mapping reads from.