What are the default values for meta model slots?

[candleindark]

Is there a systematic way to look up the default value for a meta model slot?

I know that the required meta model slot has a default of false from experimentation and the default_range slot has a default of string from documentation. However, I haven't found a way look up the default value for an arbitrary meta model slot. Is there such a way? If there is, what is it?

Ping @djarecka

[cmungall]

Some metamodel elements will have ifabsent explicitly declared; e.g. : linkml:range

If it doesn't have this you can assume there is no default

Booleans are a special case and this should be better documented: rather than thinking of these having a default of false, think of this in terms of truthiness, i.e None is "falsy"

[candleindark]

@cmungall Thanks for the answer.

default_range doesn't have a ifabsent declared, so it doesn't have a default, and the documentation regarding the default of default_range is wrong. I also confirmed the mistake in the documentation with the following schema and data instance.

personinfo.yaml

id: https://w3id.org/linkml/examples/personinfo
name: personinfo
prefixes:
  linkml: https://w3id.org/linkml/
  personinfo: https://w3id.org/linkml/examples/personinfo
imports:
  - linkml:types
default_prefix: personinfo

classes:
  Person:
    attributes:
      id:
      full_name:
      aliases:
      phone:
      age:

data.yaml

id: ORCID:1234
full_name: Clark Kent
age: 32
phone: 555-555-5555

Running the following command produces no error.

❯ linkml-validate -s personinfo.yaml data.yaml
No issues found

With all that said, it is a bit strange to have default_range to have no default. The above schema apparently render all attributes of Person to have a range of Any.