Implement list handling functions and digit and substring functions

language/en-GB/en-GB.plg_vmshipment_rules_shipping.ini

@@ -52,4 +52,7 @@ VMSHIPMENT_RULES_EVALUATE_UNKNOWN_OPERATOR="Unknown operator '%s' encountered du
 VMSHIPMENT_RULES_EVALUATE_UNKNOWN_FUNCTION="Unknown function '%s' encountered during evaluation of rule '%s'."
 VMSHIPMENT_RULES_EVALUATE_UNKNOWN_ERROR="Unknown error occurred during evaluation of rule '%s'."
 VMSHIPMENT_RULES_EVALUATE_ASSIGNMENT_TOPLEVEL="Assignments are not allows inside expressions (rule given was '%s')"
-VMSHIPMENT_RULES_EVALUATE_UNKNOWN_VALUE="Evaluation yields unknown value while evaluating rule part '%s'."
\ No newline at end of file
+VMSHIPMENT_RULES_EVALUATE_UNKNOWN_VALUE="Evaluation yields unknown value while evaluating rule part '%s'."
+
+VMSHIPMENT_RULES_EVALUATE_LISTFUNCTION_ARGS="List function '%s' requires all arguments to be lists. (Full rule: '%s')" 
+VMSHIPMENT_RULES_EVALUATE_LISTFUNCTION_UNKNOWN="Unknown list function '%s' encountered. (Full rule: '%s')" 

rules_shipping_base.php

@@ -766,6 +766,35 @@ class ShippingRule {
 		return true;
 	}
 	
+	function evaluateListFunction ($function, $args) {
+		# First make sure that all arguments are actually lists:
+		$allarrays = True;
+		foreach ($args as $a) {
+			$allarrays = $allarrays && is_array($a);
+		}
+		if (!$allarrays) {
+			JFactory::getApplication()->enqueueMessage(JText::sprintf('VMSHIPMENT_RULES_EVALUATE_LISTFUNCTION_ARGS', $function, $this->rulestring), 'error');
+			return false;
+			
+		}
+		switch ($func) {
+			case "length":		return count($args[0]); break;
+			case "union": 
+			case "join":		return call_user_func_array( "array_merge" , $args); break;
+			case "complement":	return call_user_func_array( "array_diff" , $args); break;
+			case "intersection":	return call_user_func_array( "array_intersect" , $args); break;
+			case "issubset":	# Remove all of superset's elements to see if anything else is left: 
+						return !array_diff($args[0], $args[1]); break;
+			case "contains":	# Remove all of superset's elements to see if anything else is left: 
+						# Notice the different argument order compared to issubset!
+						return !array_diff($args[1], $args[0]); break;
+			case "list_equal":	return array_unique($args[0])==array_unique($args[1]); break;
+			default: 
+				JFactory::getApplication()->enqueueMessage(JText::sprintf('VMSHIPMENT_RULES_EVALUATE_LISTFUNCTION_UNKNOWN', $function, $this->rulestring), 'error');
+				return false;
+		}
+	}
+	
 	function evaluateFunction ($function, $args) {
 		$func = strtolower($function);
 		// Functions with no argument:
@@ -792,6 +821,20 @@ class ShippingRule {
 				case "not":   return !$args[0]; break;
 			}
 		}
+		if (count($args) == 2) {
+			switch ($func) {
+				case "digit": return substr($args[0], $args[1]-1, 1); break;
+			}
+		}
+		if (count($args) == 3) {
+			switch ($func) {
+				case "substring": return substr($args[0], $args[1], $args[2]); break;
+			}
+		}
+		// List functions
+		if (in_array($func, array("length", "complement", "issubset", "contains", "union", "join", "intersection", "list_equal"))) {
+			return evaluateListFunction ($func, args);
+		}
 		// Functions with variable number of args
 		switch ($func) {
 			case "max": return max($args); break;