Cross-Object Comparisons

Rules can compare values across different objects by referencing multiple selectors.

Comparing Across Objects

Reference different selectors in each side of a condition:

A **Application** gets approved
  if __age__ of **Applicant** is greater than 18
  and __score__ of **CreditReport** is greater than 700.

Each selector must be a key in the JSON data:

{
  "Applicant": { "age": 25 },
  "CreditReport": { "score": 750 }
}

Interactive Example

Reset

Policy Rule

A **Application** gets approved if __age__ of **Applicant** is greater than 18 and __score__ of **CreditReport** is greater than 700 and __income__ of **Applicant** is greater than 30000.

Test Data (JSON)

{ "Applicant": { "age": 30, "income": 55000 }, "CreditReport": { "score": 780 } }

▶ Run

Multiple Data Sources

This pattern is powerful for rules that combine data from different systems:

Interactive Example

Reset

Policy Rule

A **Order** is shippable if __status__ of **Order** is equal to "paid" and __verified__ of **Customer** is equal to true and __quantity__ of **Inventory** is greater than 0.

Test Data (JSON)

{ "Order": { "status": "paid", "item": "widget" }, "Customer": { "verified": true, "name": "Alice" }, "Inventory": { "quantity": 50 } }

▶ Run

Rules About the Primary Selector

The primary selector (after A/An) identifies what the rule is about. It doesn’t have to contain the properties being checked — it’s the subject of the outcome:

A **Loan** gets approved       ← the Loan is what gets approved
  if __income__ of **Applicant** is greater than 50000   ← but we check the Applicant
  and __score__ of **Credit** is greater than 700.        ← and the Credit report