How about adding them as Globals and referencing them that way? You should be able to put them in a map as well in a Global and reference them. Earnie! ________________________________ From: karthizap <karthizap(a)gmail.com&gt; To: rules-users(a)lists.jboss.org Sent: Monday, June 1, 2009 7:14:56 AM Subject: re[rules-users] move hardcoded values in DRL or have constants inside drl Is there is anyway i can remove hardcoded values in the DRL file? Can I have the constants file(like data dictionary) inside drl/functions. I don't want to refer java constants class directly in drl file and would like to declare and refer those constants inside drl file. ________________________________ View this message in context: remove hardcoded values in DRL or have constants inside drl Sent from the drools - user mailing list archive at Nabble.com.

Wolfgang makes a good point. However, given the requirement that the value changes and is not truly static, I would recommend something like the following which, if your SearchParm loads the data from a persisted source you could change it's value without any code change. Earnie! package com.sample rule "Test Rule" when SearchParam($searchName : searchName) $person : Person(name == $searchName) then System.out.println(drools.getRule().getName() + " [" + $searchName + "] [" + $person.getName() + "]"); $person.setActivation(true); end package com.sample; public class Person { private String name; private Boolean activation; public Person(String name, Boolean activation) { this.name = name; this.activation = activation; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Boolean getActivation() { return activation; } public void setActivation(Boolean activation) { this.activation = activation; } } package com.sample; public class SearchParam { private String searchName; public SearchParam(String searchName) { super(); this.searchName = searchName; } public String getSearchName() { return searchName; } public void setSearchName(String searchName) { this.searchName = searchName; } } package com.sample; import java.io.InputStreamReader; import java.io.Reader; import java.util.Properties; import org.drools.RuleBase; import org.drools.RuleBaseFactory; import org.drools.StatefulSession; import org.drools.compiler.PackageBuilder; import org.drools.compiler.PackageBuilderConfiguration; import org.drools.rule.Package; import org.drools.rule.builder.dialect.java.JavaDialectConfiguration; import org.junit.Before; import org.junit.Test; import static org.junit.Assert.*; public class GlobalTest { private RuleBase ruleBase; @Test public void testWithGlobal() { StatefulSession ss = ruleBase.newStatefulSession(); Person p = new Person("John",false); ss.insert(p); SearchParam sp = new SearchParam("John"); ss.insert(sp); ss.fireAllRules(); assertTrue(p.getActivation().equals(true)); } @Before public void buildRules() throws Exception { Reader source = new InputStreamReader(this.getClass() .getResourceAsStream("/test.drl")); Properties props = new Properties(); props.setProperty("drools.dialect.java.compiler", "JANINO"); PackageBuilderConfiguration cfg = new PackageBuilderConfiguration(props); JavaDialectConfiguration javaConf = (JavaDialectConfiguration) cfg .getDialectConfiguration("java"); javaConf.setCompiler(JavaDialectConfiguration.JANINO); PackageBuilder builder = new PackageBuilder(cfg); builder.addPackageFromDrl(source); Package pkg = builder.getPackage(); ruleBase = RuleBaseFactory.newRuleBase(); ruleBase.addPackage(pkg); } } ________________________________ From: Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; To: Rules Users List <rules-users(a)lists.jboss.org&gt; Sent: Monday, June 1, 2009 7:57:36 AM Subject: Re: re[rules-users] move hardcoded values in DRL or have constants inside drl But assigning a value to a global isn't straightforward - you can't do it in the declaration. You'll have to do it from the application (or use some dirty hack, in a start-up rule); either way it's separate from the declaration. IMHO, using a Java class with public static final is definitely cleaner. -W 2009/6/1 Earnest Dyke <earniedyke(a)yahoo.com&gt;: _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Karthizap, The only thing I could think of for you is to use a function in the DRL to store your "name" value, but any solution where you change your DRL will require you to redeploy the DRL file (obviously). Since your "name" changes quite often, can't you make it a fact of your reasoning process? Just to keep with the "Person" theme, make a helper class called AssignedName or something like that and do: when AssignedName( $an : name ) Person( name == $an ) then end This will even prevent re-deployments of the DRL itself. Also, a join like the above has cost O(1), so extremely good perf also (better than a function call). Drools does not support constants declaration in the DRL file, as you know, but maybe this is something we could add. Do you want to open a JIRA with a feature request for that? (That would still require DRL redeployment discussed above, obviously). Edson 2009/6/1 karthizap <karthizap(a)gmail.com&gt; -- Edson Tirelli JBoss Drools Core Development JBoss, a division of Red Hat @ www.jboss.com