Eclipse Community Forums: M2T (model-to-text transformation) » [Xpand/Xtend] Deleting elements from one List affects the elements on another List

Home » Modeling » M2T (model-to-text transformation) » [Xpand/Xtend] Deleting elements from one List affects the elements on another List(How to delete elements from List in the right way?)

Show: Today's Messages :: Show Polls :: Message Navigator

[Xpand/Xtend] Deleting elements from one List affects the elements on another List [message #662411]

Wed, 30 March 2011 15:02

mrodrigo Missing name

Messages: 6
Registered: March 2011

Junior Member

Hello all,

I have a problem when trying to delete elements from one List.

Here is my scenario: I have two List, 'ancestors' and 'orderedList'. The first one contains, temporally, elements collected during a loop iteration. The second one is made to contain, permanently, all 'ancestors' values. And when the rule 'removeAllElements()' deletes elements from 'ancestors', the elements from 'orderedList' are, magically, deleted too.

The code of each rule is:
Xpand rule to obtain full hierarchy tree

«DEFINE fullyHierarchyOUList(List unorderedList, List orderedList) FOR gormas_model»
  «LET (List) {} AS ancestors»
  «FOREACH unorderedList AS unorderedNode»
    «REM» Delete values from previous iteration «ENDREM»
    «ancestors.removeAllElements() -> ""»

    «LET (List)unorderedNode AS unorderedNodeAsList»

    «REM» Search for ancestors in recursive way «ENDREM»    
    «searchParent(unorderedNodeAsList, ancestors, unorderedList.reject(e|e==unorderedNodeAsList))»
    «REM» Add ancestors to final List «ENDREM»
    «orderedList.add(ancestors)»
   
    «ENDLET» «REM» End of LET (List)unorderedNode AS unorderedNodeList «ENDREM»
  «ENDFOREACH»
  «ENDLET» «REM» End of LET (List) {} AS ancestors «ENDREM»
«ENDDEFINE»

Xtend function to delete elements from List

List removeAllElements(List objectList) : {
	if objectList.size > 0 then (
		objectList.remove(objectList.last()) ->		
		removeAllElements(objectList)
	)
};

Xtend recursive function to search for ancestors

Void searchParent(List[OrganizationalUnit] lastCheckedNodeAsList, List ancestors, List unorderedList): {
    ancestors.add(((OrganizationalUnit)lastCheckedNodeAsList.first())) ->
    if lastCheckedNodeAsList.size > 1 then 
    searchParent( ((List)(unorderedList.select(e|((List) e).first() == lastCheckedNodeAsList.last()).first())), ancestors, unorderedList.reject(e|e==lastCheckedNodeAsList) )
};

With these entries:

unorderedList = [[University], [Center, University], [Department, University], [Laboratoty, Department]]
orderedList = []

The required results are:

orderedList = [[University], [Center, University], [Department, University], [Laboratoty, Department, University]]

However, the results obtained are:

orderedList = [[Laboratory, Department,University], [Laboratory, Department,University], [Laboratory, Department,University], [Laboratory, Department,University]]

Somebody understands it? This issue is driving me crazy.

Regards.

Report message to a moderator

Re: [Xpand/Xtend] Deleting elements from one List affects the elements on another List [message #662481 is a reply to message #662411]

Wed, 30 March 2011 19:03

Christian Dietrich

Messages: 14665
Registered: July 2009

Senior Member

Hi,

i don't know why you make this so complicated

List getAncestors(List lastCheckedNodeAsList, List unorderedList): 
	{lastCheckedNodeAsList.first()}.addAll(lastCheckedNodeAsList.size == 1 ? {} : getAncestors(
	 ((List)(unorderedList.select(e|((List) e).first() == lastCheckedNodeAsList.last()).first())), 
	  unorderedList.reject(e|e==lastCheckedNodeAsList)));
	  
Void doTheStuff(List unorderedList, List orderedList) :
	orderedList.addAll(unorderedList.collect(unorderedNode|getAncestors((List)unorderedNode, unorderedList.reject(e|e==unorderedNode))));

may do the same as your template and extensions do.

~Christian

Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator