Fabric Composer o vs -->

Question

I can't find any docs on this, so what is the difference between o and --> in Fabric Composer, and under what circumstances should they be used?

Consider this...

asset Document identified by docId {
    o String docId
    o Articles[] articles
}

vs this...

asset Document identified by docId {
    o String docId
    --> Articles[] articles
}

score 4 · Accepted Answer · answered Apr 09 '17 at 13:59

4

There is a document about CTO language. This document mentions about has-a relationship (o) and reference (-->).

answered Apr 09 '17 at 13:59

Tanaka Hiroyuki

2

the link is broken – Carlos Huggins Jul 18 '18 at 22:32
This is the working link: https://hyperledger.github.io/composer/v0.19/reference/cto_language.html – Riccardo Apr 16 '19 at 07:43

score 0 · Answer 2 · edited Jun 20 '20 at 09:12

0

I'm just learning about Hyperledger, but I saw a reference in this video https://youtu.be/6nGIptzBZis?t=17m (minute 17 and beyond).

'o' indicates has-a relationship

'-->' indicates pass by reference

Hope that helps =)

edited Jun 20 '20 at 09:12

Community

answered Apr 06 '17 at 14:18

eladio_tercios

1

I would not refer to `-->` as "pass by reference" -- it is declaring something more like a foreign key relationship in DB terms, or just a relationship in entity-relationship terms. Essentially it is a typed pointer to an instance. – Dan Selman Apr 25 '17 at 08:23
@DanSelman just quoting the text on the slide in the link provided :) – eladio_tercios Apr 25 '17 at 14:18

2 Answers2