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iterate

Short summary​

This method returns the next object in the iteration and returns an execution state. Example: You have a list: 1 2 3 the first iterate call will return CNM_ReturnTypes.BUSY and object = 1 the second iterate call will return CNM_ReturnTypes.BUSY and object = 2 the third iterate call will return CNM_ReturnTypes.BUSY and object = 3 the forth iterate call will return CNM_ReturnTypes.SUCCESS and object = NULL

Return: SingleExecutionState.SUCCESS: Iteration finished, no new elements, returned NULL object SingleExecutionState.ERROR: error during iteration SingleExecutionState.ABORT: iteration aborted SingleExecutionState.BUSY: returned an element and iteration in progress SingleExecutionState.IDLE: ready for iteration

Parameters​

NameTypeCommentKind
executeBOOL-input
objectCNM_AbstractObject.IObject-output

Code​

Declaration​

METHOD iterate : CNM_ReturnTypes.SingleExecutionState
VAR_INPUT
	execute	: BOOL;
END_VAR
VAR_OUTPUT
	object :CNM_AbstractObject.IObject;
END_VAR
VAR
	tmp : POINTER TO CNM_AbstractObject.Object;
END_VAR
VAR_INST
	cycleManager :CNM_CycleManager.SimpleCycleManager;
	lastExecute :BOOL;
	lastChangeVersion :__XWORD;
END_VAR
VAR CONSTANT
	INIT :DINT := CNM_ReturnTypes.DefaultSteps.STEP.INIT;
	ITERATING :DINT := INIT + 1;
	ERROR :DINT := CNM_ReturnTypes.DefaultSteps.STEP.ERROR;
	SUCCESS :DINT := CNM_ReturnTypes.DefaultSteps.STEP.SUCCESS;
	NULL: __XWORD := 0;
END_VAR

Implementation​

iterate := CNM_ReturnTypes.SingleExecutionState.ERROR;
RETURN (NOT THIS^.isObjectValid(THIS^.tree));
cycleManager(execute := execute);
CASE cycleManager.step.current OF
INIT:
	cycleManager.configuration.sequence.requireSuccessStep := FALSE;
	lastChangeVersion := THIS^.changes;
	THIS^.nodeList.clear();
	THIS^.currentNode := THIS^.getStartNode();
	IF THIS^.isObjectValid(THIS^.currentNode) THEN
		THIS^.processStartNode(THIS^.currentNode);
		THIS^.currentObject := THIS^.currentNode.object;
	ELSE
		THIS^.currentObject := 0;
	END_IF 
	
	cycleManager.proceedWith(
		step := SEL(
			THIS^.hasNext(),
			SUCCESS,
			ITERATING
		)
	);
ITERATING:
	IF lastChangeVersion <> THIS^.changes THEN
		iterate := CNM_ReturnTypes.SingleExecutionState.ERROR;
		cycleManager.proceedWith(ERROR);
		RETURN;
	END_IF
	IF(THIS^.hasNext()) AND_THEN  THIS^.getNextTreeNode(node => THIS^.currentNode) THEN
		THIS^.currentObject := THIS^.currentNode.object;
		THIS^.processNode(THIS^.currentNode);
	ELSE
		cycleManager.proceedWith(SUCCESS);
		THIS^.currentObject := NULL;
	END_IF
END_CASE

iterate := cycleManager.state;
object := THIS^.currentObject;