apoc.trigger deletedNodes should return all properties for the node

[abccbaandy]

Guidelines

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Expected Behavior (Mandatory)

deletedNodes should return all properties for the node

Actual Behavior (Mandatory)

deletedNodes return empty properties map, with negative element id

How to Reproduce the Problem

Simple Dataset (where it's possibile)

//Insert here a set of Cypher statements that helps us to reproduce the problem
CREATE(n:SomeNew {uuid:"2d3d53e5-352f-4d2b-bbbe-656b4bcc2b34"})

Steps (Mandatory)

1. add trigger

:use system;
CALL apoc.trigger.install(
  'neo4j',
  'add delete node log',
  '
      UNWIND $deletedNodes as n
      WITH n
      WHERE NOT "Log" in labels(n)
      CREATE (log:Log)
      SET 
	  log.data=apoc.convert.toJson(properties(n)), 
	  log.nodeId = elementId(n)
  ',    
  {phase:'afterAsync'}
);

2. delete the node

MATCH(n:SomeNew {uuid:"2d3d53e5-352f-4d2b-bbbe-656b4bcc2b34"})
DELETE n

3. query the log node

MATCH(n:Log)
RETURN n

Screenshots (where it's possibile)

The result

data | {} |
nodeId | -2

Specifications (Mandatory)

Currently used versions

Versions

• OS: Window
• Neo4j: 5.26.1
• Neo4j-Apoc: 5.26.1

[gem-neo4j]

Hi there!

Thanks for writing in :) The triggers reference Virtual Nodes and Relationships which means the properties function doesn't work on it, try updating you query to use apoc.any.properties(n) instead:

:use system;
CALL apoc.trigger.install(
  'neo4j',
  'add delete node log',
  '
      UNWIND $deletedNodes as n
      WITH n
      WHERE NOT "Log" in labels(n)
      CREATE (log:Log)
      SET 
	  log.data=apoc.convert.toJson(apoc.any.properties(n)), 
	  log.nodeId = elementId(n)
  ',    
  {phase:'afterAsync'}
);

The element id is not supported yet for the way these virtual nodes are created, so that is a bug, I will create a ticket for this part.

I see the documentation is lacking any information about this limitation so will make a ticket for my team to fix up. Let me know if this solves your issue! Thanks :D

[abccbaandy]

Thanks, the apoc.any.properties way works.

I think it's better throw exception if a function does not work with vNode or it's very error prone.

[gem-neo4j]

Yep, unfortunately the error part would actually need to be implemented on the Neo4j side. There is a card someone else made who had encountered a similar issue so that may one day be fixed.

We have updated the docs now too, so I will close this :) Thanks for writing in!