Is it possible to add a field to a relationship to specify the type?
For example, assuming that in Account I am storing Data about a property and the relationship with specific Contact owners and tenants.
Is it possible to add a field where you can specify if you are a Tenant or an Owner?
Taking into account that a Contact can be a tenant in one Account and an Owner in another account at the same time
Yes it is possible, but it is very tricky. I mean very.
If you are feeling brave and capable of handling tutorials with 30+ steps inviting PHP code changes, let me know and I’ll send you a few links and wish you good luck.
The core code has an example of this (in Opportunities module, I believe). It’s a pity that is not easier to make, fields in relationships are often useful…
You can always add an inbetween module only holding your property and the link to the left and right module.
It is less prone to errors, but of course not as elegant as the solution stated by @pgr
I did this once, and you have to be extremely careful with naming and so on. I think it was definitions in basically 3 or 4 files, like metadata vardefs and subpaneldefs.