Is there a way to have a rule in one object that references properties from a different object? - jsonschema

Question

I could not find any examples of this so I'm assuming it's not possible, but want to confirm.
I have a main schema that references other schemas:
https://www.jsonschemavalidator.net/s/4aLvXa4I
{
"$defs": {
"mainSchema": {
"$id": "https://example.com/person.schema.json",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"type": "object",
"properties": {
"objectOne": {
"$ref": "#/$defs/objectOne"
},
"objectTwo": {
"$ref": "#/$defs/objectTwo"
}
}
},
"objectOne": {
"type": "object",
"properties": {
"checkThisValue": {
"type": "string",
"enum": [
"one",
"two",
"three"
]
}
}
},
"objectTwo": {
"type": "object",
"properties": {
"whenSettingThisValue": {
"type": "string",
"enum": [
"A",
"B",
"C"
]
}
}
}
},
"$ref": "#/$defs/mainSchema"
}
I want to define this rule:
IF objectOne.checkThisValue == one
THEN objectTwo.whenSettingThisValue MUST == A
Same for two=>B and three=>C
Is this possible somehow? How do I reference objectOne properties inside of objectTwo?
Edit
I tried to create an if rule for objectTwo that references objectOne here, but my syntax is wrong because it's not working. whenSettingThisValue is set to C and it's saying valid when it should be invalid: https://www.jsonschemavalidator.net/s/NNjEIhWW
"objectTwo": {
"type": "object",
"properties": {
"whenSettingThisValue": {
"type": "string",
"enum": [
"A",
"B",
"C"
]
}
},
"if": {
"properties": {
"objectOne": {
"checkThisValue": {
"const": "one"
}
}
}
},
"then": {
"properties": {
"objectTwo": {
"whenSettingThisValue": {
"const": "A"
}
}
}
}
}
},
I also tried using a oneOf rule in mainSchema where both the subschemas are used, but it is not working either (this example should be invalid): https://www.jsonschemavalidator.net/s/WkmMasDC
"mainSchema": {
"$id": "https://example.com/person.schema.json",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"type": "object",
"properties": {
"objectOne": {
"$ref": "#/$defs/objectOne"
},
"objectTwo": {
"$ref": "#/$defs/objectTwo"
}
},
"oneOf": [
{
"type": "object",
"properties": {
"objectOne": {
"checkThisValue": {
"const": "one"
}
},
"objectTwo": {
"whenSettingThisValue": {
"const": "A"
}
}
}
}
]
},
Solution
Per answer my OneOf rule was malformed. This correctly checks a value in one object is set in response to another. I thought because I was referencing them in another schema with $ref I would have to do something special, but I don't.
https://www.jsonschemavalidator.net/s/HcVhrShk
"oneOf": [
{
"type": "object",
"properties": {
"objectOne": {
"properties": {
"checkThisValue": {
"const": "one"
}
}
},
"objectTwo": {
"properties": {
"whenSettingThisValue": {
"const": "A"
}
}
}
}
},
{
"type": "object",
"properties": {
"objectOne": {
"properties": {
"checkThisValue": {
"const": "two"
}
}
},
"objectTwo": {
"properties": {
"whenSettingThisValue": {
"const": "B"
}
}
}
}
}
]
},

Answer 1

Yes you can. There is an if/then/else construct which takes schemas as its arguments, so you can define a rule "if property A exists with value X, then property B must exist with value Y" etc.
There are some examples here:
https://json-schema.org/understanding-json-schema/reference/conditionals.html#if-then-else
edit:
in your re-edit, change the oneOf clause to this:
"oneOf": [
{
"type": "object",
"properties": {
"objectOne": {
"properties": {
"checkThisValue": {
"const": "one"
}
}
}
}
},
{
"type": "object",
"properties": {
"objectTwo": {
"properties": {
"whenSettingThisValue": {
"const": "A"
}
}
}
}
}
]