get value for first id of linked entities

[diyoyo]

Hi,
I have an entity A that is linked in a Many-To-Many relationship to an entity B.
When creating a new A, I want to do the following flow:
- if A has not been linked to any B in the creation form, then A.name is required
- if A has been linked to at least one B in the creation form, then A.name is not required
- if A.name is empty and at least one B is linked to the new A, then A.name becomes B[0].name

I have a problem with the last part.
here is my formula for A, concatenating 'Bonjour' to the first Id of Bs as a test of validity:

ifThen(name==null && bsIds!=null && array\length(bsIds)>0, name=string\concatenate('Bonjour',bsIds[0]));

But even with this simple test, bsIds[0] does not return anything.
Also, I had tried the condition bsNames!=null and array\length(bsNames)>0 but bsNames seems to be empty, compared to bsIds (which means that my next question will be : how to retrieve bsNames[0] instead of bsIds[0] ?)

Thanks.

[jurnet]

Have you solved your problem ? I try to do the same thing

[yuri]

In the next version there will be the new function record\findRelatedOne