Reference

public struct Reference : Codable

extension Reference: Equatable

extension Reference: Hashable

Represents an attribute name or path expression identifying a value within a Context.

This can be used to retrieve a value with LDContext.getValue(_:), or to identify an attribute or nested value that should be considered private with LDContextBuilder.addPrivateAttribute(_:) (the SDK configuration can also have a list of private attribute references).

This is represented as a separate type, rather than just a string, so that validation and parsing can be done ahead of time if an attribute reference will be used repeatedly later (such as in flag evaluations).

If the string starts with ‘/’, then this is treated as a slash-delimited path reference where the first component is the name of an attribute, and subsequent components are the names of nested JSON object properties. In this syntax, the escape sequences “~0” and “~1” represent ‘~’ and ‘/’ respectively within a path component.

If the string does not start with ‘/’, then it is treated as the literal name of an attribute.

For instance, if the JSON representation of a context is as follows–

{
  "kind": "user",
  "key": "123",
  "name": "xyz",
  "address": {
    "street": "99 Main St.",
    "city": "Westview"
  },
  "a/b": "ok"
}

– then

• Reference(“name”) or Reference(“/name”) would refer to the value “xyz”
• Reference(“/address/street”) would refer to the value “99 Main St.”
• Reference(“a/b”) or Reference(“/a~1b”) would refer to the value “ok”