Rulesets - PhilipSkinner/elemental-lowcode GitHub Wiki

Rulesets allow you to define a series of rules, which are evaluated upon your given input value - defined using JSON schema.

Each rule contains zero of more comparitors and a single output value. Each rule is evaluated in turn until all of the comparitors within a rule return true, at which point it returns that rules output value.

If no rule is triggered then a null value is returned.

Fact Schema

The facts input into a ruleset are defined using JSON schema. The schema is defined within the facts property of the ruleset:

{
    "facts": {
        "type": "object",
        "properties": {
            "value": {
                "type": "string"
            }
        }
    }
}

To read more about JSON schema and how to define object structures with it, refer to the JSON schema documentation.

Rules

Each rule contains:

• Zero or more comparitors
• An output value

Rules are defined:

{
	"rules": [
        {
            "comparitors": [
                {
                    "input": "$.value",
                    "operator": "eq",
                    "value": "hello"
                }
            ],
            "output": true
        },
        {
            "comparitors": [],
            "output": false
        }
    ]
}

A rule with zero comparitors will always evaluate to true and return its output value.

The following comparitor operators are supported.

• Equal - eq
• Not Equal - ne
• Contains - contains
• Does not contain - does not contain
• Greater than - gt
• Greater than or equal to - gte
• Less than - lt
• Less than or equal to - lte
• Is null - is null
• Is not null - is not null