<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<style>
<!--
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:Arial;
color:windowtext;}
@page Section1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.Section1
{page:Section1;}
-->
</style>
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi all<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I am trying to write a custom package builder in order to
create rules programmatically.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The most important feature are simple tests against object
attributes like:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>“if (position.getValue() > 100) then”<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>In Drools 3 I managed this the following way:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=black
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'>LiteralDescr literalDescr = </span></font><b><font size=2
color="#7f0055" face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:#7F0055;font-weight:bold'>new</span></font></b><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:black'> LiteralDescr(</span></font><font size=2
color="#2a00ff" face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:#2A00FF'>"value"</span></font><font size=2
color=black face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'>, </span></font><font size=2 color="#2a00ff" face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:#2A00FF'>">"</span></font><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:black'>, </span></font><font size=2 color="#2a00ff"
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:#2A00FF'>"100");</span></font><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=black
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'> </span></font><font
size=2 face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color="#3f7f5f"
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:#3F7F5F'>// define what class the rule refers to</span></font><font
size=2 face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=black
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'>ColumnDescr columnDescr = </span></font><b><font size=2
color="#7f0055" face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:#7F0055;font-weight:bold'>new</span></font></b><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:black'> ColumnDescr(</span></font><font size=2
color="#2a00ff" face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:#2A00FF'>"com.sample.bl.Position"</span></font><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:black'>, </span></font><font size=2 color="#2a00ff"
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:#2A00FF'>"p"</span></font><font size=2 color=black
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'>);</span></font><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=black
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'>columnDescr.addDescr(literalDescr);</span></font><font size=2
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=black
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'> </span></font><font
size=2 face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color="#3f7f5f"
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:#3F7F5F'>// assemble condition</span></font><font size=2
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=black
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'>AndDescr andDescr = </span></font><b><font size=2 color="#7f0055"
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:#7F0055;font-weight:bold'>new</span></font></b><font size=2 color=black
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:black'> AndDescr();</span></font><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:black'>andDescr.addDescr(columnDescr);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:black'>ruleDescriptor.setLhs(andDescr);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:black'>packageDescriptor.addRule(ruleDescriptor);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Upgrading to Drools 4 the above code breaks and in search of
a replacement for ColumnDescr I stumbled across a FieldConstraintDescr which seems
appropriate according to the Pattern Entity Relationship Diagram (Figure 6.11)
of paragraph 6.5 in the documentation.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Using it throws the following exception:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=red
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:red'>Exception in thread "main" </span></font><u><font size=2
color=navy face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:navy'>org.drools.RuntimeDroolsException</span></font></u><font size=2
color=red face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:red'>: BUG: no builder found for descriptor class class
org.drools.lang.descr.FieldConstraintDescr</span></font><font size=2
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=red
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:red'> at org.drools.rule.builder.GroupElementBuilder.build(</span></font><u><font
size=2 color=navy face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:navy'>GroupElementBuilder.java:77</span></font></u><font
size=2 color=red face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:red'>)</span></font><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=red
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:red'> at
org.drools.rule.builder.RuleBuilder.build(</span></font><u><font size=2
color=navy face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:navy'>RuleBuilder.java:53</span></font></u><font size=2 color=red
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:red'>)</span></font><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 color=red
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:red'> at
org.drools.compiler.PackageBuilder.addRule(</span></font><u><font size=2
color=navy face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:navy'>PackageBuilder.java:420</span></font></u><font size=2 color=red
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:red'>)</span></font><font size=2 face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=red face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:red'> at
org.drools.compiler.PackageBuilder.addPackage(</span></font><u><font size=2
color=navy face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:navy'>PackageBuilder.java:283</span></font></u><font size=2 color=red
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New";
color:red'>)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=red face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:red'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>What does that mean? Did I misunderstand the concept? Is
there an easier way to achieve what I want?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I appreciate any hints.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks and regards,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Andreas<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
</div>
</body>
</html>