Example 11: Add a new rule from a template to a rule set

IBM BPM, V8.0.1, All platforms > Programming IBM BPM > Business rule management programming > Examples

Example 11: Add a new rule from a template to a rule set

In this example, a new rule is added from a template to a rule set. Before the new rule instance is created, parameters for the new rule instance are created.

package com.ibm.websphere.sample.brules.mgmt;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.ibm.wbiserver.brules.mgmt.BusinessRule;
import com.ibm.wbiserver.brules.mgmt.BusinessRuleGroup;
import com.ibm.wbiserver.brules.mgmt.BusinessRuleManagementException;
import com.ibm.wbiserver.brules.mgmt.BusinessRuleManager;
import com.ibm.wbiserver.brules.mgmt.Operation;
import com.ibm.wbiserver.brules.mgmt.Parameter;
import com.ibm.wbiserver.brules.mgmt.ParameterValue;
import com.ibm.wbiserver.brules.mgmt.query.QueryOperator;
import com.ibm.wbiserver.brules.mgmt.ruleset.RuleBlock;
import com.ibm.wbiserver.brules.mgmt.ruleset.RuleSet;
import com.ibm.wbiserver.brules.mgmt.ruleset.RuleSetRuleTemplate;
import
com.ibm.wbiserver.brules.mgmt.ruleset.RuleSetTemplateInstanceRule;

public class Example11
{
static Formatter out = new Formatter();

static public String executeExample11()
{
	try
	{
		out.clear();
		// Retrieve a business rule group by target namespace and 		name
		List<BusinessRuleGroup> brgList = BusinessRuleManager
			.getBRGsByTNSAndName(
			"http://BRSamples/com/ibm/websphere
			/sample/brules", 			QueryOperator.EQUAL, 			"ApprovalValues", 			QueryOperator.EQUAL, 0, 0);

		if (brgList.size() > 0)
		{
			// Get the first business rule group from the list
			// This should be the only business rule group in the 			list as 			// the combination of target namespace and name are 			unique
			BusinessRuleGroup brg = brgList.get(0);
			// Get the operation of the business rule group that 			// has the business rule that will be modified as 			// the business rules are associated with a specific 			// operation 			Operation op = brg.getOperation("getApprover");

			// Get the business rule on the operation that will 			be modified 			List<BusinessRule> ruleList =
			op.getBusinessRulesByName(
				"getApprover", QueryOperator.EQUAL, 0,0);

			if (ruleList.size() > 0)
			{
				out.println("");
				out.printlnBold("Rule set before publish:");
				// Get the rule to be modified. Rules are unique by 				// target namespace and name, but for this example 				// there is only one business rule named
				"getApprover"
				RuleSet ruleSet = (RuleSet) ruleList.get(0);
				out.print(RuleArtifactUtility.printRuleSet(rule
				Set));

In order to add a new rule to the rule set, the appropriate template must be located in the rule set and an instance created from the template. The template can be located by name.

				// Get the list of rule templates
				ListRuleSetRuleTemplate> ruleTemplates =
				ruleSet
					.getRuleTemplates();

				Iterator<RuleSetRuleTemplate> templateIterator
				= ruleTemplates
					.iterator();

				while (templateIterator.hasNext())
				{
					RuleSetRuleTemplate template =
					templateIterator.next();

					// Locate the template to use to create a 					new rule
					if
					(template.getName().equals("Template_Larg
					eOrder"))
					{

For a template instance, a list of parameters must be created.

					// Create a list for the parameters 					for this template 					// rule instance 					List<ParameterValue> paramList =
					new ArrayList<ParameterValue>();

					// From the template definition, 					get a specific parameter 					// and set the value 					Parameter param =
					template.getParameter("param0");
					ParameterValue paramValue = param
						.createParameterValue("
						20");

					// Add parameter to the list
					paramList.add(paramValue);

					// Get the next parameter and set 					the value 					param = template.getParameter("param1");
					paramValue = 
					param.createParameterValue("7500");

					// Add parameter to the list
					paramList.add(paramValue);

					// Get the next parameter and set 					the value 					param =
					template.getParameter("param2");
						paramValue = param
						.createParameterValue("
						2nd-line manager");

					// Add parameter to the list
					paramList.add(paramValue);

With the parameters created, the template instance can be created.

					// Create the template rule
					instance with the parameter 					// list
					RuleSetTemplateInstanceRule
						templateInstance = template 						.createRuleFromTemplate
						("ExtraLargeOrder", 						paramList);
					// Get the ruleblock for the rule
						set
					RuleBlock ruleBlock =
					ruleSet.getFirstRuleBlock();

Once the template instance is created, it can be added to the ruleblock. Once it is added to the rule block it can be ordered among other template rule instances.

					// Add the template rule to the 					ruleblock
					ruleBlock.addRule(templateInstance)
					;
																
					break;
					} 				} 
				// Use the original list or create a new list
				// of business rule groups 				List<BusinessRuleGroup> publishList = new
				ArrayList<BusinessRuleGroup>();

				// Add the changed business rule group to the 				list
				publishList.add(brg);

				// Publish the list with the updated business 				rule group 				BusinessRuleManager.publish(publishList, true);

				out.println("");

				// Retrieve the business rule groups again to 				verify the 				// changes were published
				out.printlnBold("Rule set after publish:");

				brgList = BusinessRuleManager
				.getBRGsByTNSAndName(
						"http://BRSamples/com/ibm/websphere
						/sample/brules", 						QueryOperator.EQUAL, 						"ApprovalValues", 						QueryOperator.EQUAL, 0, 0);

				brg = brgList.get(0);
				op = brg.getOperation("getApprover");
				ruleList = op.getBusinessRulesByName(
									"getApprover", QueryOperator.EQUAL, 									0, 0);

				ruleSet = (RuleSet) ruleList.get(0);
				out.print(RuleArtifactUtility.printRuleSet(rule
				Set));
				} 		} 	} catch (BusinessRuleManagementException e)
	{
		e.printStackTrace();
		out.println(e.getMessage());
	} 	return out.toString();
	} }

Example

Web browser output for example 11.

Executing example11

Rule set before publish:
Rule Set
Name: getApprover
Namespace: http://BRSamples/com/ibm/websphere/sample/brules
Rule: LargeOrderApprover
Display Name: LargeOrderApprover
Description: null
Expanded User Presentation: If the number of items order is above 10 and 
the order is above $5000, then it requires the approval of supervisor
User Presentation: If the number of items order is above {0} and the order 
is above ${1}, then it requires the approval of {2} Parameter Name: param0
Parameter Value: 10
Parameter Name: param1
Parameter Value: 5000
Parameter Name: param2
Parameter Value: supervisor
Rule: DefaultApprover
Display Name: DefaultApprover
Description: null
Expanded User Presentation: approver = peer
User Presentation: approver = {0} Parameter Name: param0
Parameter Value: peer

Rule set after publish:
Rule Set
Name: getApprover
Namespace: http://BRSamples/com/ibm/websphere/sample/brules
Rule: LargeOrderApprover
Display Name: LargeOrderApprover
Description: null
Expanded User Presentation: If the number of items order is above 10 and 
the order is above $5000, then it requires the approval of supervisor
User Presentation: If the number of items order is above {0} and the order 
is above ${1}, then it requires the approval of {2} Parameter Name: param0
Parameter Value: 10
Parameter Name: param1
Parameter Value: 5000
Parameter Name: param2
Parameter Value: supervisor
Rule: DefaultApprover
Display Name: DefaultApprover
Description: null
Expanded User Presentation: approver = peer
User Presentation: approver = {0} Parameter Name: param0
Parameter Value: peer
Rule: ExtraLargeOrder
Display Name:
Description: null
Expanded User Presentation: If the number of items order is above 20 and 
the order is above $7500, then it requires the approval of 2nd-line manager User Presentation: If the number of items order is above {0} and the order 
is above ${1}, then it requires the approval of {2} Parameter Name: param0
Parameter Value: 20
Parameter Name: param1
Parameter Value: 7500
Parameter Name: param2
Parameter Value: 2nd-line manager

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