Override expressions

Use an override expression to modify a Record value by changing the value of one or more of its fields. An override expression:

Creates a new Record value where one or more fields have new values, without changing the original value.
Converts a JSON object value into a Record value.
Provides a convenient way to assign multiple values to the field of Record value using one Assign step instead of multiple steps.

The override expression has the following forms:

<Expr>{ "<FieldName>": <Expr>, … , "<FieldName>": <Expr>}
<Expr>{<Expr>}

For detailed information about expressions in Robots and how they are edited and evaluated, see Expressions.

If "person" is a variable containing a Record value:

Person{id: 13, name: "Joe", age: -1, male: false}

then the override expression

person{ "age": 42, "male": true }

creates a new Record value:

Person{id: 13, name: "Joe", age: 42, male: true}

To change the value of the variable "person," assign the result of the expression to this value using an Assign step. Then the override result changes only the value of the fields "age" and "male."

If "person" is a variable containing a Record value:

Person{id, 13, name: "", age: 0, male: false}

and "json" is a JSON variable with a JSON object value:

{ "name": "Joe", "age": 42, "male": true}

then the override expression

person{ json }

creates a new Record value:

Person{id: 13, name: "Joe", age: 42, male: true}

All the fields of the Record value that correspond to the keys defined in the JSON object are overridden with the values of the keys from the JSON object.

The JSON object does require key-value pairs for all the fields of the Record value. Only the key-value pairs it has are overridden. However, if you try to override JSON object values for which the Record does not have corresponding fields, then an exception is thrown during execution.