Or Container replicant

I have an 'or container' that contains multiple replicant containers. One of the replicants should be limited to 1 max and be able to move up and down in position. Is there a way to prevent multiple instances of one of the replicants?

example:
<container name="container" location="container" min="0" max="unbounded" combination="or" default="0">
<container name="container1" location="container1" /> // max one
<container name="container2" location="container2" /> //max unbounded
<container name="container3" location="container3" /> //max unbounded
</container>

Find more posts tagged with

Comments

nipper

Can be done with a significant amount of FormAPI.

This is non-trivial. You need to trap the event before the replicant is added, determine what type it is and then see if it should be allowed.

JasilM

That's what I was afraid of. No magic bullet on this one.

I am able to detect if an instance of container1 exists when a new Replicant is added and prevent or allow the addition based on that. However I can't find a way to determine which replicant was selected to be added.

ISCBorisB

That's what I was afraid of. No magic bullet on this one.

I am able to detect if an instance of container1 exists when a new Replicant is added and prevent or allow the addition based on that. However I can't find a way to determine which replicant was selected to be added.

"OnReplicantBeforeAdd" Event Handler actually gets three parameters, not two as documented.

Third Parameter is "type", it is set to the name of the yet-to-be-added Replicant Container.
Check it and if the single slot for this Type has been already occupied warn your User
and return false to cancel "ReplicanAdd" action. Return true otherwise.

Beware! This is a hack, neither documented nor supported.

nipper

In addition, there are some timing issues. IIRC, if you use the BeforeReplicant event, then the replicant type is not available. You have to play with a timeout to get the type of container and then allow/not

The other approach is a little more brute force, but should be workable. Use the onReplicantAdded event (I do not remember if it is Add or Added) and then remove the newly added replicant if you do not want it.

JasilM

Thanks for the info on the type parameter on onReplicantBeforeAdd. I may play around with that and see if it causes any issues.

[Editing first version of this post due to incorrect assumptions on my part.]

After doing some experimentation with the type parameter, it does seem to do the trick and it's a fairly simple solution. I will continue testing to make sure this is stable.

if OnReplicantBeforeAdd with the type parameter presents any problems, I can use onReplicantAdded to allow the replicant to be added and sending an alert asking the User to remove one. Followed up with a second verification onSave. Not as perty, but it will work as well.