<br> Yes, it is possible to prevent the evaluation of part of the LHS patterns by the use of previous constraints and/or the introduction of control facts.<br><br> For instance:<br><br><div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">rule "avoid expense"</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">when</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">ControlFact( phase == "do expensive call" )</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">AnotherFact( ) from
someExpensiveServiceCall</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">then</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">// Do something</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">end</font></font></span></div>
<span></span><br> In the above example, the "someExpensiveServiceCall" will only be executed when the previous patterns are matched, i.e., when phase attribute of the ControlFact has the value "do expensive call".<br>
<br> []s<br> Edson<br><br><div><span class="gmail_quote">2008/2/6, Anstis, Michael (M.) <<a href="mailto:manstis1@ford.com">manstis1@ford.com</a>>:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">I'm not sure as LHS's are evaluated when facts are inserted
not when fireAllRules (or execute) is called.</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">You can prevent the RHS from activating by using (for lack
of a better name) "flag facts" (but this doesn't solve your problem); for
example:-</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">rule "avoid expense"</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">when</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">not exists Flag()</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">AnotherFact( ) from
someExpensiveServiceCall</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">then</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">// Do something</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">end</font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Don't forget though that if you share LHS patterns across
multiple rules they will share the same nodes in the RETE network, so although
you might be aware that the expensive calls are not required for some rules they
might be required for other rules and hence you'll need to perform the expensive
call when the facts are inserted in order for the other rules to activate.
Perhaps if you better describe your use-case there might be a better
solution.</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">With kind regards,</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Mike</font></span></div><br>
<blockquote style="margin-right: 0px;">
<div dir="ltr" align="left" lang="en-us">
<hr>
<font face="Tahoma" size="2"><span class="q"><b>From:</b> <a href="mailto:rules-users-bounces@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users-bounces@lists.jboss.org</a>
[mailto:<a href="mailto:rules-users-bounces@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users-bounces@lists.jboss.org</a>] <b>On Behalf Of </b>Jai
Vasanth<br></span><b>Sent:</b> 05 February 2008 19:35</font><div><span class="e" id="q_117ee125616fbe29_3"><font face="Tahoma" size="2"><br><b>To:</b> Rules Users
List<br><b>Subject:</b> Re: [rules-users] Grouping rules<br></font></span></div><br></div><div><span class="e" id="q_117ee125616fbe29_5">
<div></div>I had another question on these lines. Is there a way to preven
even the LHS from evaluating for certain cases ? A few of my LHS computation
involve some expensive service calls and I would like to avoid unless and
until it is asolutely necessary.<br><br>Thanks <br><br>Jai <br><br>
<div class="gmail_quote">On Feb 1, 2008 8:35 AM, Jai Vasanth <<a href="mailto:jaivasanth@gmail.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">jaivasanth@gmail.com</a>> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Thanks.
That helped.
<div>
<div></div>
<div><br><br>
<div class="gmail_quote">On Feb 1, 2008 7:31 AM, Anstis, Michael (M.) <<a href="mailto:manstis1@ford.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">manstis1@ford.com</a>>
wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Excuse
me if you already understand but there is a difference between rule
patterns being evaluated and their consequence
running.</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Rules
LHS are evaluated when objects are inserted into working memory whereas
the consequence fires when you call fireAllRules();</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">The
rules whose activations are executed are those in the given Agenda Group;
thereafter those not in any agenda group execute. So if all rules are in
an Agenda Group you should be OK.</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Of
course they don't prevent all rule patterns from being checked as
objects are inserted into WM (which has a performance impact) but this is
what the RETE network was designed to optimise. </font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">You
could try another configuration (but I think Agenda Groups are
probably the preference by design). This gives complete isolation - but I
haven't tried it so it might not even be possible ;-)</font></span></div>
<blockquote dir="ltr" style="margin-right: 0px;">
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">global WorkingMemory wm;</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">global RuleBase rbX;</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" size="2">
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">global RuleBase rbY;</font></span></div></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">rule "Group X"</font></span></div>
<div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">when</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">Fact( attribute == "condition1"
)</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">then</font></font></span></div></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">wm =
rbX.newStatefulSession();</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">wm.fireAllRules();</font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">end</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2"></font></span> </div>
<div dir="ltr" align="left"><span>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">rule "Group Y"</font></span></div>
<div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">when</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">Fact( attribute == "condition2"
)</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">then</font></font></span></div></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">wm =
rbY.newStatefulSession();</font></font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"> <font color="#0000ff" size="2">wm.fireAllRules();</font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">end</font></span></div></span></div></blockquote>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Good
luck.</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Mike</font></span></div><br>
<blockquote style="margin-right: 0px;">
<div dir="ltr" align="left" lang="en-us">
<hr>
<font face="Tahoma" size="2">
<div><b>From:</b> <a href="mailto:rules-users-bounces@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users-bounces@lists.jboss.org</a> [mailto:<a href="mailto:rules-users-bounces@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users-bounces@lists.jboss.org</a>] <b>On Behalf Of
</b>Jai Vasanth<br></div><b>Sent:</b> 01 February 2008
15:07<br><b>To:</b> Rules Users List<br><b>Subject:</b> Re:
[rules-users] Grouping rules<br></font><br></div>
<div>
<div></div>
<div>
<div></div><br>Thanks for responding <br>Yes, I did consider
agenda groups, but I thought agenda groups only ordered execution in a
particular fashion, so if Rule "pick group X" fires then it would make
sure that rules in Agenda Group X fire first before the remaining but
the remaining would fire eventually. Is my understanding correct
?<br>I am looking for a solution for completely isolating a rule
set conditioned on an object attribute.<br><br>
<div class="gmail_quote">On Feb 1, 2008 12:46 AM, Anstis, Michael (M.)
<<a href="mailto:manstis1@ford.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">manstis1@ford.com</a>> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">What about Agenda Groups?</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">Rule "pick group X"</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">when</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"><font size="2"> <font color="#0000ff">Fact( attribute =
"condition1" )</font></font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">then</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"><font size="2"> <font color="#0000ff">drools.setFocus("Group
X")</font></font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">end</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">Rule "pick group Y"</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">when</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"><font size="2"> <font color="#0000ff">Fact( attribute =
"condition2" )</font></font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">then</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"><font size="2"> <font color="#0000ff">drools.setFocus("Group
Y")</font></font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">end</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">Rule "Group X1"</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">Agenda Group "Group X"</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">when</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"><font size="2"> <font color="#0000ff">Smurf(
)</font></font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">then</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"><font size="2"> <font color="#0000ff">// Do
something</font></font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">end</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">Rule "Group X2"</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">Agenda Group "Group X"</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">when</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"><font size="2"> <font color="#0000ff">Smurfette(
)</font></font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">then</font></span></div>
<div dir="ltr" align="left"><span><font face="Courier New"><font size="2"> <font color="#0000ff">// Something
else</font></font></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Courier New" size="2">end</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">etc</font></span></div><br>
<blockquote style="margin-right: 0px;">
<div dir="ltr" align="left" lang="en-us">
<hr>
<font face="Tahoma" size="2"><b>From:</b> <a href="mailto:rules-users-bounces@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users-bounces@lists.jboss.org</a> [mailto:<a href="mailto:rules-users-bounces@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users-bounces@lists.jboss.org</a>] <b>On Behalf
Of </b>Jai Vasanth<br><b>Sent:</b> 31 January 2008
19:45<br><b>To:</b> <a href="mailto:rules-users@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users@lists.jboss.org</a><br><b>Subject:</b>
[rules-users] Grouping rules<br></font><br></div>
<div>
<div></div>
<div>
<div></div>Hi,<br><br><br> I am building a system where I would
need to fire different sets of rules based on some attribute in the
fact object. <br><br>Here are someways which I thought of, I
was wondering if there was something better than that.<br><br>1) I
could do this by creating different sessions based on the data
attrbute (different sessions would have different rule packages
based on the attribute)<br><br>or <br><br>2) Have all the rules fire
(all the different sets of rules) irrespective of the attribute and
have them insert fact new objects into the working memory. In the
second round of rules, collect the (newly made) fact objects
based on the attribute and take that action.<br><br><br><br>Thanks
<br><br>Jai
<br><br><br><br><br></div></div></blockquote></div><br>_______________________________________________<br>rules-users
mailing list<br><a href="mailto:rules-users@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users@lists.jboss.org</a><br><a href="https://lists.jboss.org/mailman/listinfo/rules-users" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">https://lists.jboss.org/mailman/listinfo/rules-users</a><br>
<br></blockquote></div><br></div></div></blockquote></div><br>_______________________________________________<br>rules-users
mailing list<br><a href="mailto:rules-users@lists.jboss.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">rules-users@lists.jboss.org</a><br><a href="https://lists.jboss.org/mailman/listinfo/rules-users" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">https://lists.jboss.org/mailman/listinfo/rules-users</a><br>
<br></blockquote></div><br></div></div></blockquote></div><br></span></div></blockquote></div>
<br>_______________________________________________<br>rules-users mailing list<br><a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:rules-users@lists.jboss.org">rules-users@lists.jboss.org</a><br><a onclick="return top.js.OpenExtLink(window,event,this)" href="https://lists.jboss.org/mailman/listinfo/rules-users" target="_blank">https://lists.jboss.org/mailman/listinfo/rules-users</a><br>
<br><br clear="all"></blockquote></div><br><br clear="all"><br>-- <br> Edson Tirelli<br> JBoss Drools Core Development<br> Office: +55 11 3529-6000<br> Mobile: +55 11 9287-5646<br> JBoss, a division of Red Hat @ <a href="http://www.jboss.com">www.jboss.com</a>