You can implement
... and nowhere says anything about the Rules module.
Of course, if the customer (= user asking the question) is happy (the answer is accepted ...), then why bother, right? Well sorry, but that was not the question, I thought the question was about "(How to) Create rule to Set Default Value".
I flagged that answer like "not an answer" ... and I posted a comment below that answer like so:
The question is about using the Rules module to get this to work. How does this answer help to do so?
My flag got declined, and @Clive added this surprising comment below that answer:
"Don't use rules, do it this way because it's better, simpler and more performant" is a perfectly acceptable answer to "how do I do x with rules".
Wablieft? (oeps: I beg your pardon?) Really? So then this is my new meta question (part of my subsequent comment, which @Clive recommended to post on meta.drupal.SE):
Thanks for teaching me about this. Does that mean that the opposite is true also then. E.g. to answer questions (about Views) like "Don't use Views, here is how you can use module X as an alternative because it's better, simpler and more performant". BTW: you must know the value of "X" I have in mind ... (disclosure: I'm a co-maintainer of module X).
I leave it to @Clive to eventually repeat here on meta what he wrote in his other (interesting) comments. Here is 1 more comment I added to that answer:
... for any D8 question to get something to work in Rules, would you (yes or no) consider something like this "sensible" then: "You cannot do this with Rules in D8 yet, if you want it badly, then you can perfectly do this with D7, using a rule that looks like so and so.". Can't imagine you'd say "yes" (though I'd hope ...), so where to draw the line?
PS 1: If you want another example (more food for thoughts?), how about questions related to OG, where I'd answer with module Y (of which I'm NOT a (co-)maintainer, in case that would make a difference to answer this meta question here).
PS 2: I'm aware of the meta question about "The answer is not really an answer", however:
- It's unclear to me what that question is actually about. Actually that is not a question (knowing that the title of a question is not to be considered as part of the question). IMO it's rather like a service request to do something about the answer to "Cannot install Open Atrium".
- I don't think the answers to that question are of any help to answer my question here.