Root Node Singleton
Hi,
I'm currently trying to implement a unique constraint dependent on a particular root node concept. Let's say I have a root node concept R, I want to ensure that this concept has only one instance per model. Hence, I implemented two checks/restrictions:
To my current understanding, the concept constraint is for restraining the auto-completion menu when creating a new node. To my surprise, the second check is also performed after node creation. Since it seems to be not possible to access the node, that is "currently in creation" I haven't found any way to condition my second rule.
Does anybody have an idea? Do I miss anything?
Thank you very much in advance,
LaAck
I'm currently trying to implement a unique constraint dependent on a particular root node concept. Let's say I have a root node concept R, I want to ensure that this concept has only one instance per model. Hence, I implemented two checks/restrictions:
- I used a Non-Typesystem Rule for reporting an error in case of multiple instances of R. B
- I created a concept constraint for "can be root" as follows:
model.roots(R).size == 0
To my current understanding, the concept constraint is for restraining the auto-completion menu when creating a new node. To my surprise, the second check is also performed after node creation. Since it seems to be not possible to access the node, that is "currently in creation" I haven't found any way to condition my second rule.
Does anybody have an idea? Do I miss anything?
Thank you very much in advance,
LaAck
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Vaclav
thank you very much for your fast reply. Using the concept constraint leads to an odd behavior, since I'm able to insert a new node of type R if none is present, yet. But afterwards the same checking mechanisms mark the inserted node as an error. Is this behavior desired?
Thanks again,
LaAck