jsonschema - JSON Schema: XOR on required fields -

json schemas have a required property, lists required fields in json object. example, following (simplified) schema validates call sends text message user:

{   "type": "object",   "properties": {     "userid":    { "type": "string" },     "text":      { "type": "string" },   },   "required": ["userid", "text"] } 

suppose want enable sending message multiple users, i.e. have either userid field, or array of userids (but not both or neither). there way express such condition in json schema?

naturally, there ways overcome problem in case - example, userid array single element - general case interesting , useful.

not elegant @ all, think can hack out allof , oneof. like:

 {    "allof" : [       {         "type" : "object",         "properties" : {           // base properties come here         }       },       "oneof" : [         {         "properties" : {              "userids" : {"type" : "array"}           },           "required" : ["userids"]         },         {           "properties" : {              "userid" : {"type" : "number"}           },           "required" : ["userid"]         }       ]    ] }