I have a use case where I will take a json-schema as input, validate it, then keep in my system. Later I will get json data which I need to validate with above mentioned json-schema. given the scenario, I need to do two level of validations:
1. provided json-schema is valid or not.
2. Json is valid or not.
I am using json-schema-validator jar and could find only second level of validation, couldn't find json-schema validation in documentation. for example: lets say we have below sample json-schema:
{
"title": "Person",
"type": "object",
"properties": {
"firstName": {
"type": "string"
},
"lastName": {
"type": "string"
},
"age": {
"description": "Age in years",
"type": "integer",
"minimum": 0
}
},
"required": ["firstName", "lastName"]
}
so how to validate this json-schema itself is valid or not?
There is a working example here with the everit-org/json-schema implementation (just in case you want to use a maintained library):
How to validate a json schema against the version spec it specifies in Java
You have to validate schema against meta-schema: http://json-schema.org/draft-04/schema
Related
I ran into this situation recently and would like to check my understanding, with a JSON (draft-7) schema.
additionalProperties is set to false, which means every property in our JSON object MUST be listed in the properties array.
the required array contains category, which is not in the properties array.
{
"$schema": "https://json-schema.org/draft-07/schema#",
"$id": "/my-schema-1.0.0",
"description": "My schema",
"type": "object",
"additionalProperties": false,
"properties": {
"value": {
"description": "The value.",
"type": "number"
}
},
"required": [
"value",
"category"
]
}
However, whenever i try to validate that my schema is valid, multiple validators say that it is.
But then i don't think you can create an object that would ever validate successfully against this schema.
I don't see anything within the JSON spec that mentions this conflict. Is anyone able to shed any light on this?
I have the following use-case I try to solve with JSON schemas.
I have a generic JSON data schema for, for example, a user. Here is an example of the user.schema.json file.
{
"type": "object",
"definitions": {},
"$schema": "http://json-schema.org/draft-07/schema#",
"properties": {
"name": {
"type": "string",
"minLength": 1
},
"email": {
"type": "string",
"minLength": 1
},
"locale": {
"type": "string",
"minLength": 1
},
"active": {
"type": "boolean",
"default": true
},
"password": {
"type": "string",
"minLength": 8
},
"roles": {
"type": "array",
"items": {
"type": "string",
"minLength": 1
}
}
}
}
Now I have 2 different kinds of requests:
- POST: Add a user
- PATCH: Update user data.
In 1 case, I can send this data structure, with 3 required fields, while in case of a patch each field is optional.
So I get the post request file: post-user.schema.json:
{
"$schema": "http://json-schema.org/draft-07/schema#",
"$ref": "user.schema.json",
"required": [
"name",
"password",
"email"
]
}
And for my patch (path-user.schema.json:
{
"$schema": "http://json-schema.org/draft-07/schema#",
"$ref": "user.schema.json"
}
Now the issue that I am having is that my POST schema also marks a user like:
{
"name": "NoPassword",
"email": "nopassword#moba.nl",
"roles": []
}
Which is missing the required password field, as a valid JSON schema.
Apparently, this is not the way to assign required fields to a referenced data structure. I have tried to use google to see what I can find on the subject regarding this using searches like:
[ how to assign required field to referenced schema's ]
and I tried to obtain this info from the documentation.
I have no luck.
My questions now are:
A. Is it possible to assign required fields to a $referenced json schema data object.
B. If this is possible how to do it
C. If this is not possible, what would be a good way to approach this.
Any help is much appreciated.
Using $ref results in all other properties in the object being ignored, so you need to wrap your use of $ref.
Let's take a look at the spec:
An object schema with a "$ref" property MUST be interpreted as a
"$ref" reference. The value of the "$ref" property MUST be a URI
Reference. Resolved against the current URI base, it identifies the
URI of a schema to use. All other properties in a "$ref" object MUST
be ignored.
https://datatracker.ietf.org/doc/html/draft-handrews-json-schema-01#section-8.3
Then consider the schema you included in your question:
{
"$schema": "http://json-schema.org/draft-07/schema#",
"$ref": "user.schema.json",
"required": [
"name",
"password",
"email"
]
}
Reading the spec, you can see why required will be ignored.
Originally $ref was only designed to replace a WHOLE object, not ADD to the conditions for the object.
What you want is for multiple schemas to be applied to the instance. To do this, you use allOf.
{
"$schema": "http://json-schema.org/draft-07/schema#",
"allOf": [
{
"$ref": "user.schema.json"
},
{
"required": [
"name",
"password",
"email"
]
}
]
}
I loaded this schema into a demo for you to test at https://jsonschema.dev - although it doesn't support references yet, so I transcluded the reference, but the validation will work the same.
From draft-8 onwards, $ref will behave as you expect, as it becomes an applicator keyword rather than a keyword with special behaviours, meaning other keywords in the same object will not need to be ignored.
I'm trying to create a JSON schema for an existing JSON file that looks something like this:
{
"variable": {
"name": "age",
"type": "integer"
}
}
In the schema, I want to ensure the type property has the value string or integer:
{
"variable": {
"name": "string",
"type": {
"type": "string",
"enum": ["string", "integer"]
}
}
}
Unfortunately it blows up with message: ValidationError {is not any of [subschema 0]....
I've read that there are "no reserved words" in JSON schema, so I assume a type of type is valid, assuming I declare it correctly?
The accepted answer from jruizaranguren doesn't actually answer the question.
The problem is that given JSON (not JSON schema, JSON data) that has a field named "type", it's hard to write a JSON schema that doesn't choke.
Imagine that you have an existing JSON data feed (data, not schema) that contains:
"ids": [ { "type": "SSN", "value": "123-45-6789" },
{ "type": "pay", "value": "8675309" } ]
What I've found in trying to work through the same problem is that instead of putting
"properties": {
"type": { <======= validation chokes on this
"type": "string"
}
you can put
"patternProperties": {
"^type$": {
"type": "string"
}
but I'm still working through how to mark it as a required field. It may not be possible.
I think, based on looking at the "schema" in the original question, that JSON schemas have evolved quite a lot since then - but this is still a problem. There may be a better solution.
According to the specification, in the Valid typessection for type:
The value of this keyword MUST be either a string or an array. If it is an array, elements of the array MUST be strings and MUST be unique.
String values MUST be one of the seven primitive types defined by the core specification.
Later, in Conditions for successful validation:
An instance matches successfully if its primitive type is one of the types defined by keyword. Recall: "number" includes "integer".
In your case:
{
"variable": {
"name": "string",
"type": ["string", "integer"]
}
}
I need a help regarding schema extraction by property.
For example i have a JSON schema:
{
"$schema": "http://json-schema.org/draft-04/schema#",
"description": "A simple address format",
"type": "object",
"properties": {
"street-name": { "type": "string" },
"locality":{ "type": "string" },
"region": { "type": "string" },
"postal-code": { "type": "int" },
"country-name": { "type": "string"}
},
"required": ["locality", "region", "country-name"]
}
I have an use case, where i need to extract the schema corresponding to each property and send to another service, where it will do validation against the value and save in database. Here is the sample object i need to send to another service.
{
"propertyName": "street-name",
"value": "19, Canton street",
**"schema": { "type": "string" }**
}
The questions is,
how we extract the schema for a particular property from a give JSON schema??
Given the property path, Is there any nodejs module exists to do this schema extraction? or if there is any other solutions exists ?
Because this is very simple scenario, but if we have array, anyOf, OneOf type its getting complicated;
Thanks in advance ! Please let me know if the question is not clear !
sadish
The swagger-spec repository provides a JSON-schema describing a valid Swagger 2.0 API definition.
I would like to use this schema in order to validate if a given API definition file is valid before I try to interpret it.
I'm using the following code to load the schema using Json.NET:
JsonSchema swaggerApiSchema;
using (var textReader = new JsonTextReader(new StreamReader(#"C:\path\to\schema.json")))
{
swaggerApiSchema = JsonSchema.Read(textReader);
}
This throws an ArgumentException reporting "Can not convert Array to Boolean.".
Is there something wrong with the schema file, is this a bug with Json.NET, or am I just doing something wrong?
As per documentation, JSON.NET implements JSON Schema Draft 3. More here. But the Swagger schema you posted is created according to the JSON Schema Draft 4. One of the differences between the Draft 3 and Draft 4 of the JSON Schema is the required attribute, which in JSON Schema Draft 3 was an attribute of subschemas in properties. In JSON Schema Draft 4 is a first level keyword playing the same role, and has a string array as an argument.
Sample of JSON Schema Draft 3:
{
"properties": {
"Id": {
"required": true,
"type": "integer"
},
"FirstName": {
"required": true,
"type": "string",
},
"LastName": {
"required": true,
"type": "string
}
}
}
Sample of JSON Schema Draft 4:
{
"properties": {
"Id": {
"type": "integer"
},
"FirstName": {
"type": "string"
},
"LastName": {
"type": "string"
}
},
"required": [ "Id", "FirstName", "LastName" ]
}
Notice the difference in the two schemas, of how required properties are defined. That's why you are getting an error: "Can not convert Array to Boolean.".
And here is the first appearance of required property in the Swagger JSON Schema, that is causing the error:
"required": [ "swagger", "info", "paths" ]
I would suggest to validate with parser that implements JSON Schema Draft 4.