Write DRY JSON-Schema with Python classes, inherit classes for new JSON-Schema-Version

This supports only jsonschema Draft4Validator at this time

Install

pip install https://github.com/level96/json-schema-oop.git#egg=jsonschemaoop

Example

We want to validate an address-schema with following data

location = {
    'address': {
        'street': 'john doe street',
        'street_number': '12 a',
        'zip': '12345',
        'city': 'Berlin'
    }
}

Create a schema object

from JSONSchemaOOP import JSONObject, JSONString, JSONType, JSONNumber

class AddressJSONSchemaObject(JSONObject):
    required = ['street', 'street_number', 'zip', 'city']
    properties = {
        'street': JSONString(),
        'street_number': JSONString(),
        'zip': JSONType(JSONNumber(), JSONString),
        'city': JSONString(),
    }

Create a schema, put SchemaObject to the definitions or properties

from JSONSchemaOOP import JSONSchema, JSONSchemaReference

class AddressSchema(JSONSchema):
    properties = {
        'address': JSONSchemaReference('address')
    }
    definitions = {
        'address': AddressJSONSchemaObject()
    }

Now validate the location object. This uses Draft4Validator(obj).validate(data). It returns nothing on success and raises jsonschema.exceptions.ValidationError if Schema doesn't match

schema = AddressSchema()

schema.validate(location)

Now Address-Schema has changed. city is renamed to location and a new array-field staff is added. Let's reflect this to our AddressJSONSchemaObject and add a new Version AddressJSONSchemaObjectV2

location = {
    'address': {
        'street': 'john doe street',
        'street_number': '12 a',
        'zip': '12345',
        'location': 'Berlin',
        'staff': ['John']
    }
}

class AddressJSONSchemaObjectV2(AddressJSONSchemaObject):
    def get_required(self):
        required = super(AddressJSONSchemaObjectV2, self).get_required()
        required.discard('city')
        required.add('location')
        return required

    def get_properties(self):
        properties = super(AddressJSONSchemaObjectV2, self).get_properties()
        properties.pop('city', None)
        properties.update(
            location=JSONString(),
            staff=JSONArray(
                min_items=1,
                items=[JSONSchemaOOP.JSONString()]
            )
        )
        return properties

Now update AddressSchema

class AddressSchemaV2(AddressSchema):
    definitions = {
        'address': AddressJSONSchemaObjectV2()
    }