Retain existing values using field map script

[Evren Yamin]

Hello,

Is there a way to retain existing values of the field when using a transform map?

My requirement is for example I have this record on group table:

group name = cab approval

type = itil

Then I'm using transform map to update this record. The data I'm loading for example is:

group name = cab approval

type = catalog

What needs to happen after transform is:

group name = cab approval

type = itil, catalog

I need to retain the existing value of the type field on the group table after transform. If not empty then update, if empty then inser

Appreciate all the help.

[-O- · Accepted solution]

The code does not implement the part where it is supposed to check whether the current list already contains the item to be added. I would go with a field map script as below:

answer = (function transformEntry (source, target, action, log) {
	var groupTypeUniqueValues = getGroupTypeUniqueValues('' + source.u_sys_user_group_type);

	return addTypeToNewGroup(action, groupTypeUniqueValues) ||
		addTypeToGroupWithNoType(target.type.nil(), groupTypeUniqueValues) ||
		addTypeToGroupWithType(getGroupTypes('' + target.type), groupTypeUniqueValues);

	function addMissingTypes () {
		return function (existingValues, newValue) {
			if (existingValues.indexOf(newValue) < 0)
				existingValues.push(newValue);

			return existingValues;
		};
	}

	function addTypeToGroupWithNoType (typeIsEmpty, value) {
		if (typeIsEmpty)
			return value.join(',');
	}

	function addTypeToGroupWithType (existingValues, newValues) {
		return newValues
			.reduce(addMissingTypes(), existingValues)
			.join(',');
	}

	function addTypeToNewGroup (action, value) {
		if (action == 'insert')
			return value.join(',');
	}

	function getGroupTypes (groupTypeList) {
		return groupTypeList
			.split(semiColonCommaOrNewLineSorrundedByWhiteSpace())
			.filter(retainNotEmpty())
			.filter(retainUnique());
	}

	function getGroupTypeUniqueValues (groupTypeList) {
		return groupTypeList
			.split(semiColonCommaOrNewLineSorrundedByWhiteSpace())
			.filter(retainNotEmpty())
			.map(getUniqueValueFromDisplayValue('sys_user_group_type'))
			.filter(retainNotEmpty())
			.filter(retainUnique());
	}

	function getUniqueValueFromDisplayValue (tableName) {
		return function getUniqueValueFromDisplayValue (displayValue) {
			return '' + GetIDValue(tableName, displayValue);
		};
	}

	function retainNotEmpty () {
		return function retainNotEmpty (item) {
			return item != '';
		};
	}

	function retainUnique () {
		return function retainUnique (item, index, items) {
			return items.indexOf(item) == index;
		};
	}

	function semiColonCommaOrNewLineSorrundedByWhiteSpace () {
		return /\s*[;,\n]\s*/g;
	}

})(source, target, action, log);

answer;

Tested it with a field map setup in a transform map as below: