Explain indirect relationships more clearly

[Altreus]

It is unclear how indirect relationships (using :model<ModelName> to define them) are implemented, just from the examples.

I had an issue whereby my Red setup did not know how to find a model, because it was not in a file by that name:

# Schema.pm6
model A {
  has Int $.id is serial;
  has    @.rel is relationship({.a-id }, :model<B>);
}

model B {
  has Int $.id is serial;
  has Int $!b-id is referencing{ :model<B>, :column<id> };
}

The parameter :require<Schema> can be used to tell Red that it should load that module to find that relationship, but this can be cumbersome. A bigger example might be:

# lib/MyApp/Schema/A.pm6
model LongTableName {
  has Int $.id is serial;
  has    @.rel is relationship({.a-id }, :model<RealLongTableName>, :require<MyApp::Schema::RealLongTableName>);
}

A possible solution (I don't know whether this is feasible since I am still experimenting with Perl 6) would be to remember a model once it is declared; Red already makes use of global state, so this doesn't seem like a terrible option if it can be done. That way, you would only need to know how to find a :model if it hasn't been seen before, and the way to use Red would be to make sure all your models have been loaded before you do anything else.

[Altreus]

Right - I misunderstood the meaning of $*RED-DB cos I'm still learning Perl6 as well :P

I think what I was about to propose is #7 - I would like this.