Re: [rules-users] RE: Hi.

Sanjay,

2007/3/26, Anstis, Michael (M.) < manstis1(a)ford.com&gt;: > > Hi Sanjay, > > To firstly answer your questions (in my opinion): > 1. You can't do nested whens in the LHS but you can do nested if / else > in the RHS (although you'd fore go the benefits of a RETE-based inference > engine; but possible if you've got very few rules and facts...). I believe > that there is work to have an "otherwise" statement for rule syntax, how > progressed this is and how it will work I don't know - over to Mark and > team?!? > 2. Yes, take a look at the "from" statement (new for 3.1-M1, see > http://wiki.jboss.org/wiki/Wiki.jsp?page=3.1M1ReleaseNotes) > 3. Yes, take a look at rule-flow at > http://labs.jboss.com/portal/index.html?ctrl:cmd=render&ctrl:window=d... (although I don't know if this is complete if > 3.1-M1 - I think it's not). Although I don't think your rules really > need rule-flow; you just need to identify and isolate the patterns (IF's) > that would cause each "Do Something" to be ran and create a rule for each - > this has the benefit of separating each action into a separate rule making > maintenance a whole bunch easier). > > Anyway, I'd try some rules like the following examples (the rest are > based upon these):- > > Rule "Rule 1" > when > NewItem ( itemStatusCode == null) > then > //do something > end > > Rule "Rule 2" > when > $u : User( ) > $ni : NewItem ( $isc : itemStatusCode != null ) > not Codes ( codes contains $isc ) from > valDao.getValidItemStatusCodesForUser($u) > then > //Do something > end > > Rule "Rule 3" > when > $u : User( ) > $ni : NewItem( itemStatusCode == ItemVO.DELETED ) > Codes ( codes contains $isc ) from > valDao.getValidCrossReferencePrimeCodesForUser($u) > then > //Do something > end > > I've posted to the news group so everyone can contribute - don't be shy > ;-) > > With kind regards, > > Mike > > ------------------------------ > *From:* Sanjay Singh - s0singh [mailto:Sanjay.Singh@wal-mart.com] > *Sent:* 26 March 2007 14:24 > *To:* Anstis, Michael (M.) > *Subject:* Hi. > > Hey Mike ... I am sorry to bother you but you seemed to be pretty good > with rules and i just could not think of anyone else to ask abt it ... I am > sorry if i am taking much of your time .. Here is my problem if you can have > a quick look .. > > Look at this code once .. its very easy but it involves tons of if else > blocks conditions .. > > if( newItem.getItemStatusCode() == null){ > //do something > } > else{ > * if( !valDao.isValidItemStatus( > newItem.getItemStatusCode(),user) ){* > * //do something* > * }* > * if( newItem.getItemStatusCode().equals( > ItemVo.DELETED)||getItemStatusCode().equals(ItemVo.INACTIVE) ){* > > * if( valDao.isCrossReferencePrime( > newItem.getItemNbr(),user)){* > * //do something* > * }* > * else if( > valDao.isFutrCrossReferencePrimeOrSecond(newItem.getItemNbr(),user) ){* > * //do something* > * }* > * else if( valDao.isComponentLink( > newItem.getItemNbr(),user)){* > * //do something* > * }* > * else if( > valDao.hasWhseOnHandsOrOnOrders(newItem.getItemNbr(),user)&&CountryCode().equals("CA") > ){* > > * //do something* > * }* > * }* > * else{* > * if( > valDao.isUnlikeAsstParentWithNonActiveChildren(newItemNbr,user) ){* > * //do something;* > * }else if > (isLikeAssortmentBaby(newItemNbr,user)&&!alDao.isLikeAsstParentActive(newItemNbr, > user)){* > > * //do something > * > * }else{* > * //do something* > * }* > * }* > * }* > * * }* * > > > What i am trying to understand is the right way of putting it in drl > files .. > 1.What are the options for putting if else conditions ? Will i have to > write all the rules anyway and they will be called as well all the time > depending on the criteria ... or is there a way where when my first if check > which was if item number is null failed i should not go for any other rules > .. Is there a way where we could have like "when" inside "when" .. kinda > looping of conditions so if one does not meet you dont go to the next .. > jsut like in above blocks ? Whats the good way of doing it ? > > 2.Is it possible to make database calls like from my dao instance in LHS > (condition) .. i know we can do it in RHS and i have tested that as well but > can we do it in LHS as sometimes we need to do that ..like with null checks > for the item status code we also want to check something from the database > like a boolean value and if that meets the criteria we will run the rules > ..as u can see above we have basic state check with nulls etc plus we have > some dao calls as well in the condition part and then we //do something > > 3.Can i call rules within other rules .. so something like in rule1 i > want to call rule2 .. is that possible ? > > Can you suggest a decent way of doing these if else blocks .. this is > the core stuff which we do for our rules here .. if i can handle this kind > of conditions i guess i can handle anything out here ... > > Thanks for all the help .. > > Sanjay > > > > > ------------------------------ > > > * > ******************************************************************* > *** This email and any files transmitted with it are confidential > and intended solely for the individual or entity to whom they are > addressed. If you have received this email in error destroy it > immediately. ****************************************************** > **************** Wal-Mart Confidential **************************** > ****************************************** > * > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- Edson Tirelli Software Engineer - JBoss Rules Core Developer Office: +55 11 3124-6000 Mobile: +55 11 9218-4151 JBoss, a division of Red Hat @ www.jboss.com