Conditional Json Schema - Response dependent - json

Question

In below json example - "Vendor" is mandatory and should have some value (minLength=1), however when Mode= Ground, it always returns as blank, hence a general json schema is failing for below json response.
Json response looks like below:
{
"Res": {
"Mem": [
{
"Mode": "Flight",
"Vendor": "YP",
"MemNum": "222"
},
{
"Mode": "Ground",
"Vendor": "",
"MemNum": "242"
}
]
}
}
In json response, both "Mode" will be returned always.
Is it possible to create customized schema where i can specify:
When "Mode"="Ground", validate with schema1
for all others "Mode" take reference from schema2 for validation.
I have tried below but unable to get desired results:
{
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"required": [
"Res"
],
"properties": {
"Res": {
"type": "object",
"required": [
"Mem"
],
"properties": {
"Mem": {
"type": "array",
"allOf": [
{
"$ref": "#/definitions/Flight"
},
{
"$ref": "#/definitions/Ground"
}
]
}
}
}
},
"definitions": {
"Flight": {
"properties": {
"Mode": {
"enum": [
"Flight"
]
},
"VendorCode": {
"type": "string",
"minLength": 1,
"optional": false
},
"MemNum": {
"type": "string",
"minLength": 1,
"optional": false
}
}
},
"Ground": {
"properties": {
"Mode": {
"enum": [
"Ground"
]
},
"VendorCode": {
"type": "string"
},
"MemNum": {
"type": "string",
"minLength": 1,
"optional": false
}
}
}
}
}
Is there any other concept in json schema which can be useful in achieving desired result?

Answer 1

It is a quite awkward usecase but you can hack it together with "allOf" , "anyOf" and "not" .
Schema:
{
"oneOf" : [
{
"allOf" : [
{
"$ref" : "#/definitions/ModeIsGround"
},
{
// schema1 comes here
}
]
},
{
"allOf" : [
{
"not" : {
"$ref" : "#/definitions/ModeIsGround"
}
},
{
// schema2 comes here
}
]
}
],
"definitions" : {
"ModeIsGround" : {
"properties" : {
"Mode" : {
"enum" : ["Ground"]
}
}
}
}
}
You didn't tell in your question what is schema1 and schema2, and also your pasted schema is malformed, so I refer to these simply as schema1 and schema2, commented.
Explanation: so at the top level you say that the subject should match one of the subschemas. The first subschema says that the subject should match "ModeIsGround" and also schema1 (this is the case that you explanied as "When "Mode"="Ground", validate with schema1") . The second subschema says that the subject shouldn't match "ModeIsGround" but should match schema2 (this is the "for all others "Mode" take reference from schema2 for validation" part).
These 2 subschemas combined with "oneOf" will do what you want.
The "Mode"="Ground" predicate is expressed via the single-element enum type.
I hope it helps.