Can maxItems/minItems be used with a $ref in a JSON schema - json

Given a JSON schema with the following in the definitions section:
"phoneNumber": {
"type": "object",
"properties": {
"countryCode": {
"type": "number"
},
"areaCode": {
"type": "number"
},
"number": {
"type": "number"
},
"extension": {
"type": "number"
},
"service": {
"type": "string",
"enum": ["Voice", "Fax", "Data"]
},
"class": {
"type": "string",
"enum": ["Switchboard", "Direct", "PA", "Mobile"]
}
}
}
If I want to include phoneNumber elsewhere using a $ref and want the JSON to validate if it contains multiple occurrences of phoneNumber, can I use maxItems/minItems:
"person": {
"type": "object",
"properties": {
"name": {
"type": "string"
},
"phoneNumber": {
"$ref": "#/definitions/phoneNumber"
//can I use maxItems/minItems here?
}
}
}
Can I use maxItems and minItems here, or would I have to do something like this below for it to validate:
"phoneNumber": {
"allOf": { "$ref": "#/definitions/phoneNumber" },
"maxItems": 4
}

$ref must stand alone. The option you identified using allOf is the best way to do it.
Any members other than "$ref" in a JSON Reference object SHALL be ignored.
https://datatracker.ietf.org/doc/html/draft-pbryan-zyp-json-ref-03#section-3

Related

Allow Properties to be any string

Given the following json document:
{
"property-1": {
"server": "string-value",
"environment": "string-value",
"cluster": "string-value"
},
"property-2": {
"server": "string-value",
"environment": "string-value",
"cluster": "string-value"
}
}
I am busy doing up a json schema for this type of json document where property-1 can be any string, but inside of that, we will have a set structure with a number of required. What I am struggling with is how to define the schema so that the user will be able to set any string for property-1 | property-2.
I assume I have to use a pattern, but what I have tried haven't worked that well.
{
"$schema": "http://json-schema.org/draft/2020-12/schema",
"type": "object",
"definitions": {
"role": {
"$id": "#svcrole",
"description": "Application name for which role is required.",
"type": "object",
"pattern": "^[a-zA-Z\\-]+$",
"properties": {
"server": {
"type": "string"
},
"environment": {
"type": "string"
},
"cluster": {
"type": "string"
}
},
"required": [
"server",
"environment",
"cluster"
]
}
},
"properties": {
"$schema": {
"type": "string"
},
"$name": {
"$ref": "#/definitions/role"
}
}
}
So I stumbled upon the solution here.
You want to use propertyNames and patternProperties like:
"propertyNames": {
"pattern": "^[a-zA-Z\\-]+$"
},
"patternProperties": {
"": {
"$ref": "#/definitions/role"
}
}
That will then allow you to use a pattern to define the property name and have it all dynamic.

JSON Schema if-else condition complex scenario

{
"policyHolder": {
"fullName": "A"
},
"traveller": [
{
"fullName": "B",
"relationship": "Spouse"
},
{
"fullName": "A",
"relationship": "My Self"
}
]
}
In above json, I want to validate that
if "relationship" = "My Self" then fullName must match the fullName in policyHolder
A field relationship must exist in traveller array, else json is invalid
I have tried to create a json schema with if-else, allOf, etc. but nothing works which can do these validations but not able to.
Please help!!
Schema:
{
"type": "object",
"required": [
"policyHolder",
"traveller",
],
"properties": {
"policyHolder": {
"$id": "#/properties/policyHolder",
"type": "object",
"required": [
"fullName"
],
"properties": {
"fullName": {
"$id": "#/properties/policyHolder/properties/fullName",
"type": "string",
}
}
},
"traveller": {
"$id": "#/properties/traveller",
"type": "array",
"minItems": 1,
"items": {
"$id": "#/properties/traveller/items",
"type": "object",
"properties": {
"fullName": {
"$ref": "#/properties/policyHolder/properties/fullName"
},
"relationship": {
"$id": "#/properties/traveller/items/properties/relationship",
"type": "string",
}
},
"required": [
"fullName",
"relationship"
],
}
}
}
}```
It's your first requirement that you're going to have the most trouble with. JSON Schema doesn't support validation of data against data elsewhere in the instance. It's a highly discussed topic, but nothing has been adopted yet. I suggest you verify this with a little code.
For the second, I would suggest you extract some of your subschemas into definitions rather than trying to muck about with IDs. IDs are typically more beneficial if you're referencing them from other documents or if you use short (like single-word) IDs. Defining the ID as its location in the document is redundant; most processors will handle this automatically.
{
"type": "object",
"required": [
"policyHolder",
"traveller",
],
"definitions": {
"person": {
"type": "object"
"properties": {
"fullName": {"type": "string"}
},
"required": ["fullName"]
},
"relationship": { "enum": [ ... ] } // list possible relationships
},
"properties": {
"policyHolder": { "$ref": "#/definitions/person" },
"traveller": {
"type": "array",
"minItems": 1,
"items": {
"allOf": [
{ "$ref": "#/definitions/person" },
{
"properties": {
"relationship": { "$ref": "#/definitions/relationship" }
},
"required": ["relationship"]
}
]
}
}
}
}
(I extracted the relationship into its own enum definition, but this is really optional. You can leave it inline, or even an unrestricted string if you don't have a defined set of relationships.)
This can't currently be done with JSON Schema. All JSON Schema keywords can only operate on one value at a time. There's a proposal for adding a $data keyword that would enable doing this kind of validation, but I don't think it's likely to be adopted. $data would work like $ref except it references the JSON being validated rather than referencing the schema.
Here's what how you would solve your problem with $data.
{
"type": "object",
"properties": {
"policyHolder": {
"type": "object",
"properties": {
"fullName": { "type": "string" }
}
},
"traveler": {
"type": "array",
"items": {
"type": "object",
"properties": {
"fullName": { "type": "string" },
"relationship": { "type": "string" }
},
"if": {
"properties": {
"relationship": { "const": "My Self" }
}
},
"then": {
"properties": {
"fullName": { "const": { "$data": "#/policyHolder/fullName" } }
}
}
}
}
}
}
Without $data, you will have to do this validation in code or change your data structure so that it isn't necessary.

JSON-Schema oneOf for option under root area

I am trying to get the "oneof" to allow for options in root items but can't find an example and what I try gives an error.
I can get it to work if it is under another item but not under the root {'s
Example - a Job Payment that has required fields (jobNum, payee, amount, type, ) and an option for the payment type (checkInfo or dollarAmt). I know this could be done other ways, but I need this method for a more complex schema.
{
"jobNum": "x216",
"payee": "John Doe",
"type": "check",
"amount": "112.25",
"checkInfo": {
"number": "386"
}
}
{
"JobNum": "x216",
"Payee": "John Doe",
"type" : "Cash",
"amount" : "112.25",
"cashInfo" : {
"dollarAmt" : "112",
"coinAmt" : "0.25"
}
}
The following gives me this error - "Unexpected token encountered when reading value for 'oneOf'. Expected StartObject, Boolean, got StartArray"
{
"description": "Job Payment",
"type": "object",
"required": [ "jobNum", "payee", "amount", "type"],
"properties": {
"jobNum": {
"type": "string"
},
"payee": {
"type": "string"
},
"amount": {
"type": "string"
},
"type": {"enum": [ "check", "cash" ]
},
"oneOf": [
{ "$ref": "#/definitions/ptCash" },
{ "$ref": "#/definitions/ptCheck" }
]
},
"definitions": {
"ptCash": {
"properties": {
"checkInfo": {
"number": "string"
}
},
"required": [ "checkInfo" ],
"additionalProperties": false
},
"ptCheck": {
"properties": {
"dollarAmt": {
"type": "string"
},
"coinAmt": {
"type": "string"
}
},
"required": [ "dollarAmt", "coinAmt" ],
"additionalProperties": false
}
},
"additionalProperties": false
}
There are a a few issues with your schema. I fixed it for you below. I won't explain all the changes I made because I think it is mostly pretty clear by reading the schema. If you want more detail on anything, just ask and I'll update the answer with more details.
The oneOf keyword can only appear in a schema. The properties keyword is an object whose values are schemas. When you put "oneOf" directly under properties, it's not interpreted as a keyword, it's interpreted as a property called "oneOf". The validator then complains because the value of property "oneOf" is expected to be a schema, not an array of schemas like the oneOf keyword.
Your use of additionalProperties doesn't work. This keyword doesn't work the way people often assume that it does. JSON Schema keywords are not aware of any state outside of the schema they are in. Let's look at the "ptCheck" branch of your oneOf first. This describes the property "number", says it is required and that there may be no keywords other than "number". Then your top level defines a the properties "jobNum", "payee", "amount", and "type", requires them all and allows no other properties. These two things can never be true at the same time. Even though your schema is valid, there is no JSON value that can ever be valid against this schema. That's why I moved the definitions of "checkInfo" and "cashInfo" to the top level and only put the required part in oneOf. The only downside to this approach is that you can pass both a "checkInfo" and a "cachInfo" object and it will validate. The extraneous property gets ignored. There are ways around this, but they are problematic enough that I don't advise using them.
I always advise people not to use "additionalProperties": false and to ignore unknown properties instead. The reason is that JSON Schema is a constraint system. Any valid JSON is valid against the empty schema ({}) and each keyword in the schema adds some constraint. This is a different approach to what people are used to when defining classes. An empty class describes nothing and valid values are added. We use "additionalProperties": false to get JSON Schema to behave more like defining a class, but trying to get JSON Schema to behave like something it isn't causes challenges like the one you see here.
{
"description": "Job Payment",
"type": "object",
"required": ["jobNum", "payee", "amount", "type"],
"properties": {
"jobNum": { "type": "string" },
"payee": { "type": "string" },
"amount": { "type": "string" },
"type": { "enum": ["check", "cash"] },
"checkInfo": {
"type": "object",
"properties": {
"number": { "type": "string" }
},
"required": ["number"]
},
"cashInfo": {
"type": "object",
"properties": {
"dollarAmt": { "type": "string" },
"coinAmt": { "type": "string" }
},
"required": ["dollarAmt", "coinAmt"]
}
},
"oneOf": [
{ "$ref": "#/definitions/ptCash" },
{ "$ref": "#/definitions/ptCheck" }
],
"definitions": {
"ptCheck": {
"type": "object",
"properties": {
"type": { "enum": ["check"] }
},
"required": ["checkInfo"]
},
"ptCash": {
"type": "object",
"properties": {
"type": { "enum": ["cash"] }
},
"required": ["cashInfo"]
}
},
"additionalProperties": false
}
oneOf should be placed in prope
Have to re-write rule for both ptCash and ptCheck by using type: object
Following schema should work with ptCheck:
{
"description": "Job Payment",
"type": "object",
"required": [ "jobNum", "payee", "amount", "type"],
"properties": {
"jobNum": {
"type": "string"
},
"payee": {
"type": "string"
},
"amount": {
"type": "string"
},
"type": {"enum": [ "check", "cash" ]
}
},
"oneOf": [
{ "$ref": "#/definitions/ptCash" },
{ "$ref": "#/definitions/ptCheck" }
],
"definitions": {
"ptCash": {
"properties": {
"checkInfo": {
"type": "object",
"required": ["number"],
"properties": {
"number": {
"type": "string"
}
}
}
},
"required": [ "checkInfo" ]
},
"ptCheck": {
"properties": {
"cashInfo": {
"type": "object",
"properties": {
"dollarAmt": {
"type": "string"
},
"coinAmt": {
"type": "string"
}
},
"required": ["dollarAmt", "coinAmt"]
}
},
"required": ["cashInfo"]
}
}
}
Provide some example as below:
import jsonschema
import simplejson as json
schema_filename = '47926398.json'
with open(schema_filename, 'r') as f:
schema_data = f.read()
schema = json.loads(schema_data)
# validate with checkInfo
json_obj = {
"jobNum": "x216",
"payee": "John Doe",
"type": "check",
"amount": "112.25",
"checkInfo": {
"number": "386"
}
}
jsonschema.validate(json_obj, schema)
# invalidate
json_obj = {
"jobNum": "x216",
"payee": "John Doe",
"type": "check",
"amount": "112.25",
"checkInfox": {
"number": "386"
}
}
jsonschema.validate(json_obj, schema)
# validate with cashInfo
json_obj = {
"jobNum": "x216",
"payee": "John Doe",
"type": "check",
"amount": "112.25",
"cashInfo": {
"dollarAmt": "400",
"coinAmt": "30"
}
}
jsonschema.validate(json_obj, schema)
# invalidate with cashInfo
json_obj = {
"jobNum": "x216",
"payee": "John Doe",
"type": "check",
"amount": "112.25",
"cashInfox": {
"dollarAmt": "400",
"coinAmt": "30"
}
}
jsonschema.validate(json_obj, schema)
# invalidate with cashInfo.dollarAmtx
json_obj = {
"jobNum": "x216",
"payee": "John Doe",
"type": "check",
"amount": "112.25",
"cashInfo": {
"dollarAmtx": "400",
"coinAmt": "30"
}
}
jsonschema.validate(json_obj, schema)

JSON validation against JSON schemas: Why is this obvious JSON data not failing validation

This JSON file should fail validation but it does not. Someone tell me why.
Plug the below json data and schema into this web site, validate,
http://json-schema-validator.herokuapp.com
and I get the same results in the Mule Validate JSON Schema. Its obviously does not comply with the schema (i added some fields, I misspelled some fields, the date-time value is not a real date time) but yet it does not fail it. Can someone tell me why?
JSON Schema:
{
"$schema": "http://json-schema.org/draft-04/schema#",
"id": "http://hud.gov/ocio/xsd/esb/serviceauditingframework/2.0#",
"definitions": {
"serviceAuditLogData": {
"type": "object",
"title": "serviceAuditLogData",
"required": [
"serviceRequestTimestamp",
"sourceSystem"
],
"properties": {
"auditId": {
"type": "string"
},
"serviceRequestTimestamp": {
"type": "string",
"format": "date-time"
},
"serviceProvider": {
"type": "string"
},
"serviceProviderVersion": {
"type": "string"
},
"serviceProviderTimestamp": {
"type": "string",
"format": "date-time"
},
"eventType": {
"type": "string"
},
"eventDetail": {
"type": "string"
},
"hostName": {
"type": "string"
},
"sourceSystem": {
"type": "string"
},
"authenticationId": {
"type": "string"
},
"endUserId": {
"type": "string"
},
"inputData": {
"type": "string"
}
},
"propertiesOrder": [
"auditId",
"serviceRequestTimestamp",
"serviceProvider",
"serviceProviderVersion",
"serviceProviderTimestamp",
"eventType",
"eventDetail",
"hostName",
"sourceSystem",
"authenticationId",
"endUserId",
"inputData"
]
}
}
}
JSON Data
{
"serviceAuditLogData": {
"junk":"asdfasdf",
"serviceRequestTimestamp": "2004-09-29T12:58:31.470Z",
"serviceProvider": "FLQS",
"serviceProviderVersion": "v1.0.1",
"audit_id": "17f24136-2494-4bf8-9d3b-9baafaae0cc9",
"serviceProviderTimestamp": "2012-11-04T21:44:57.997Z",
"eventType": "Query Pool",
"eventDetail": "default pool",
"hostName": "esb-d-srv1.",
"sourceSystem": "LRS",
"authenticationId": "EsbLrsAccount",
"endUserId": "H574857",
"inputData": "L234234234, L32453462345, L23452346"
}
}
It does not fail because your schema does not enforce any constraint. Notice that definitions is not a jsonschema keyword that constraints validation. It is normally used to place sub-schemas that are re-used in other parts of the schema definition. Thus, to start with, you should change the definitions keyword for properties.
Another common misunderstanding with jsonschema is related to the properties keyword. Let's take the following example:
{
"type" : "object",
"properties" : {
"key1" : {
"type" : "string"
}
}
}
You must read it as: json must be an object, and in the case that it contains a key equal to key1, its value must be a string. According to that the following two json objects are valid:
{
"key2":12
}
And:
{
"key1":"sdf"
}
Finally, related to date-time format, you must check the section 6 of RFC3339 to be sure you have a valid date-time. And in any case, the implementation of formats is not compulsory in jsonschema validators.
Thanks #jruizaranguren I also learned that I needed to place
"additionalProperties": false, and "required": to make sure that whats' being passed in the API is what's expected.
The below is how I solved my problem.
{
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"definitions": {
"serviceAuditLogData": {
"type": "object",
"additionalProperties": false,
"required": [
"auditCorrelationId",
"serviceRequestTimestamp",
"serviceProvider",
"serviceProviderVersion",
"serviceProviderTimestamp",
"eventType",
"hostName",
"sourceSystem",
"authenticationId"
],
"properties": {
"auditCorrelationId": {
"type": "string"
},
"serviceRequestTimestamp": {
"type": "string",
"format": "date-time"
},
"serviceProvider": {
"type": "string"
},
"serviceProviderVersion": {
"type": "string"
},
"serviceProviderTimestamp": {
"type": "string",
"format": "date-time"
},
"eventType": {
"type": "string"
},
"eventDetail": {
"type": "string"
},
"hostName": {
"type": "string"
},
"sourceSystem": {
"type": "string"
},
"authenticationId": {
"type": "string"
},
"endUserId": {
"type": "string"
},
"inputData": {
"type": "string"
}
}
}
},
"additionalProperties": false,
"required": [
"serviceAuditLogData"
],
"properties": {
"serviceAuditLogData": {
"$ref": "#/definitions/serviceAuditLogData"
}
}
}

How to use definitions in JSON schema (draft-04)

The rest service response I am working with is similar to following example, I have only included 3 fields here but there are many more:
{
"results": [
{
"type": "Person",
"name": "Mr Bean",
"dateOfBirth": "14 Dec 1981"
},
{
"type": "Company",
"name": "Pi",
"tradingName": "Pi Engineering Limited"
}
]
}
I want to write a JSON schema file for above (draft-04) which will explicitly specify that:
if type == Person then list of required properties is ["type", "name", "dateOfBirth", etc]
OR
if type == "Company" then list of required properties is ["type", "name", "tradingName", etc]
However am unable to find any documentation or example of how to do it.
Currently my JSON schema looks like following:
{
"$schema": "http://json-schema.org/draft-04/schema",
"type": "object",
"required": ["results" ],
"properties": {
"results": {
"type": "array",
"items": {
"type": "object",
"required": ["type", "name"],
"properties": {
"type": { "type": "string" },
"name": { "type": "string" },
"dateOfBirth": { "type": "string" },
"tradingName": { "type": "string" }
}
}
}
}
}
Any pointers/examples of how I should handle this.
I think the recommended approach is the one shown in Json-Schema web, Example2. You need to use an enum to select schemas "by value". In your case it would be something like:
{
"type": "object",
"required": [ "results" ],
"properties": {
"results": {
"type": "array",
"items": {
"oneOf": [
{ "$ref": "#/definitions/person" },
{ "$ref": "#/definitions/company" }
]
}
}
},
"definitions": {
"person": {
"properties": {
"type": { "enum": [ "person" ] },
"name": {"type": "string" },
"dateOfBirth": {"type":"string"}
},
"required": [ "type", "name", "dateOfBirth" ],
"additionalProperties": false
},
"company": {
"properties": {
"type": { "enum": [ "company" ] },
. . .
}
}
}
}
Sorry,
I don't get the point. The question is about the 'dependencies' keyword which is part of the last JSON Schema specification, right?
I do not find 'dependencies' in the accepted answer (?)
It is briefly explained in the last draft.
But http://usingjsonschema.com explained both property and definition dependencies in the book:
http://usingjsonschema.com/assets/UsingJsonSchema_20140814.pdf
start at page 29 (see, explained at page 30)
"dependencies": {
"shipTo":["shipAddress"],
"loyaltyId":["loyaltyBonus"]
}