Embeded Table Schema

[AdrienRosi]

Related to #999

Consider two resources person and company. Each resource has it's own schema but also share a common address schema. For now, i understand i have to duplicate the address schema. The idea is to define a new table type described by à embedded schema.

From :

{
    "resources": [
        {
            "name": "person",
            "path": "http://example.com/person.csv",
            "schema": {
                "fields": [
                    { "name": "address_number" },
                    { "name": "address_street" },
                    { "name": "address_city" }
                ]
            }
        },
        {
            "name": "company",
            "path": "http://example.com/company.csv",
            "schema": {
                "fields": [
                    { "name": "address_number" },
                    { "name": "address_street" },
                    { "name": "address_city" }
                ]
            }
        }
    ]
}

to :

{
    "resources": [
        {
            "name": "person",
            "path": "http://example.com/person.csv",
            "schema": {
                "fields": [
                    {
                        "name": "address",
                        "type": "table",
                        "schema": "address.json"
                    }
                ]
            }
        },
        {
            "name": "company",
            "path": "http://example.com/company.csv",
            "schema": {
                "fields": [
                    {
                        "name": "address",
                        "type": "table",
                        "schema": "address.json"
                    }
                ]
            }
        }
    ]
}

[michael-anderson-ta]

Given that datapackage already uses json-schema, I was expecting to be able to use json-refs, eg.
{ "resources": [ { "name": "person", "path": "person.csv", "schema": { "$ref": "#/$defs/address" } }, { "name": "company", "path": "company.csv", "schema": { "$ref": "#/$defs/address" } } ], "$defs": { "address": { "fields": [ { "name": "address", "type": "table", "schema": "address.json" } ] } } }
However, it seems that this doesn't work, at least, frictionless-py doesn't like it. In any case, it doesn't provide a way to specify 2+ schemas.

If $schema was supported for nested resources, you could use json-schema to define this, but I think that would be using an extension to do something that would ideally be part of the standard functionality.