✨ Proposal: at least one property is required

[DarkLite1]

Describe the inspiration for your proposal

It would be great if it was possible to define that either field y or x is required.

Describe the proposal

If you want to send an email you can either have a to field or bcc field or both, but none is not acceptable.

"To": {
    "type": "array",
    "title": "To",
    "description": "An array of recipient email addresses.",
    "items": {
    "type": "string",
    "format": "email"
    }
},
"Bcc": {
    "type": "array",
    "title": "Bcc",
    "description": "An array of BCC email addresses.",
    "items": {
    "type": "string",
    "format": "email"
    }
},

Describe alternatives you've considered

No response

Additional context

No response

[gregsdennis]

Hey there. Thanks for the idea.

This is quite easy to do with the current keywords:

{
   "anyOf": [
     { "required": [ "to" ] },
     { "required": [ "bcc" ] }
   ]
}

This requires that at least one of the properties to be present.

[DarkLite1]

Thank you, and I'm sorry for not reading the docs properly. Your suggestion works with a small tweak as below.

schema.json

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "urn:hm:schemas:move-file-sftp-config",
  "type": "object",
  "title": "Move File Over SFTP Configuration",
  "description": "Configuration schema for moving files over SFTP.",
  "properties": {
    "Settings": {
      "type": "object",
      "title": "Settings",
      "description": "Various script settings.",
      "properties": {
        "SendMail": {
          "type": "object",
          "title": "Send Mail Settings",
          "description": "Settings for sending email notifications.",
          "properties": {
            "To": {
              "type": "array",
              "title": "To",
              "description": "An array of recipient email addresses.",
              "items": { "type": "string", "format": "email" },
              "uniqueItems": true
            },
            "Bcc": {
              "type": "array",
              "title": "Bcc",
              "description": "An array of BCC email addresses.",
              "items": { "type": "string", "format": "email" },
              "uniqueItems": true
            }
          },
          "required": [],
          "anyOf": [
            { "required": ["To"], "properties": { "To": { "minItems": 1 } } },
            { "required": ["Bcc"], "properties": { "Bcc": { "minItems": 1 } } }
          ],
          "errorMessage": "Either 'To' or 'Bcc' must contain at least one email address."
        }
      },
      "required": ["SendMail"]
    }
  },
  "required": ["Settings"]
}

test.json

{
  "Settings": {
    "SendMail": {
      "To": ["[email protected]"],
      "Bcc": []
    }
  }
}

[DarkLite1]

Hmmm, errorMessage does not seem to work. It throws:

The JSON is not valid with the schema: Value should have at least 1 items at '/Settings/SendMail/To'

Instead of the string

Either 'To' or 'Bcc' must contain at least one email address.

Found a similar issue on StackOverflow.

[gregsdennis]

errorMessage isn't a JSON Schema keyword. It's not going to do anything. It might be something that the implementation you're using has decided to support. It'd be best to ask them.

[DarkLite1]

Ah, got it. Thanks for clarifying. So there's no way to have a custom error message in case an anyOf fails?

[gregsdennis]

Custom error messages would be an implementation thing. JSON Schema doesn't mandate any kind of messaging.

[DarkLite1]

Would be a great new feature I think. But thx anyway, this was really helpful.