getNewDoublyLinkedElement

Short summary

Method to create new Instance of DoublyLinkedElements and automatically link with other ellements. This will affect/change the next and previouse elements !

Return: SingleExecutionResult.SUCCESS: allocation succesful, output element contains new list element instance SingleExecutionResult.ERROR: error during allocation, output element is NULL

• Return type: CNM_ReturnTypes.SingleExecutionResult

Parameters

Name	Type	Comment	Kind
object	CNM_AbstractObject.IObject	the dataobject to be contained inside the element	input
previousElement	CNM_CollectionInterfaces.IDoublyLinkedElement	the previous element to link to	input
nextElement	CNM_CollectionInterfaces.IDoublyLinkedElement	the next element to link to	input
linkElements	BOOL	a flag if the link to next and previous should be created	input
element	CNM_CollectionInterfaces.IDoublyLinkedElement	the created array linked list container element	output

Code

Declaration

METHOD getNewDoublyLinkedElement :CNM_ReturnTypes.SingleExecutionResult
VAR_INPUT
	(*the dataobject to be contained inside the element*)
	object					:CNM_AbstractObject.IObject;
	(*the previous element to link to*)
	previousElement			:CNM_CollectionInterfaces.IDoublyLinkedElement;
	(*the next element to link to*)
	nextElement				:CNM_CollectionInterfaces.IDoublyLinkedElement;	
	(*a flag if the link to next and previous should be created*)
	linkElements			:BOOL := TRUE;
END_VAR
VAR_OUTPUT
	(* the created array linked list container element *)
	element :CNM_CollectionInterfaces.IDoublyLinkedElement;
END_VAR
VAR
	newElement		:POINTER TO DoublyLinkedElement;
END_VAR

Implementation

getNewDoublyLinkedElement := CNM_ReturnTypes.SingleExecutionResult.ERROR;
newElement := __NEW(
	DoublyLinkedElement(
		content		:= object,
		previous	:= previousElement,
		next		:= nextElement
	)
);

IF (newElement <> 0) THEN
	IF (linkElements) THEN
		IF (THIS^.isObjectValid(previousElement)) THEN
			previousElement.next := newElement^;
		END_IF
		IF (THIS^.isObjectValid(nextElement)) THEN
			nextElement.previous := newElement^;
		END_IF	
	END_IF
	element := newElement^;
	getNewDoublyLinkedElement := CNM_ReturnTypes.SingleExecutionResult.SUCCESS;
END_IF