Re: [rules-users] RE: Hi.

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