# getParent() allways null in ArchetypeSlot nodes?

**Category:** [Reference Implementation: Java (archive)](https://discourse.openehr.org/c/reference-implementation-java-archive/154)
**Created:** 2010-01-17 05:48 UTC
**Views:** 5
**Replies:** 5
**URL:** https://discourse.openehr.org/t/getparent-allways-null-in-archetypeslot-nodes/13518

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## Post #1 by @pablo

Hi,

I've a problem with my slots in archetypes, when I do a slot.getParent(), to get the parent CAttribute of this node, I get always null.

Any ideas?

Cheers,
Pablo Pazos.

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## Post #2 by @system

Hi again,

Sorry for the delay\. The parent attribute is not set in the current
adl\-parser due to immutability of the AOM\. But this will change
quickly\. In fact, I am at the moment developing a modifiable AOM
implementation in relation to openEHR template support\. These changes
will be uploaded to the openEHR repository once they are more
stabilized and tested\.

Cheers,
Rong

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## Post #3 by @pablo

Great!

Please let me know when the update is available.

Thank you,
Pablo.

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## Post #4 by @Koray_Atalag

Hi Rong, I’d be very interested in your approach to solve immutability issue. Could you pls. comment what sort of relationship does that have with templates?

Cheers,

-koray

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## Post #5 by @system

Hi Koray,

Basically, the current AOM is made modifiable in order to combine
constraints coming both from archetypes and templates, a procedure
sometimes known as 'flattening'\. The result of that is all definitions
and constraints are represented in one big 'archetype' structure in
the form of AOM\. The major benefit of doing that is that with some
small changes, the current archetype \(AOM\-based\) tools/components will
be able to support openEHR templates\.

Cheers,
Rong

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## Post #6 by @Koray_Atalag

Hi Rong, thanks for that\.\.\.So can we say that it is sort of "operational archetype"?

My previous message was indeed mostly addressing the "mutability" of the RM classes in Java implementation so that one can add/modify/remove RM objects on the fly to create an "Archetype Instance" conforming to the AOM but ultimately defined by the user input \(i\.e\. multiplicities etc\.\)\. I know that Şeref is having difficulties at the moment with this in his implementation\. I'd be interested in your and community's views on that\.

Cheers,

\-koray

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**Canonical:** https://discourse.openehr.org/t/getparent-allways-null-in-archetypeslot-nodes/13518
**Original content:** https://discourse.openehr.org/t/getparent-allways-null-in-archetypeslot-nodes/13518