Re: [rules-users] FW: Basic rules question

I’ve written this rule to be fired for Configuration object whose category is selected and subcategories are yet not selected. rule "select sub categories"             salience 50             no-loop             when                         $conf : Configuration($categoryId : $conf.getCategory().getCategoryId() != null, subCategories == null  )                         $subcats : ArrayList() from collect (Category ( parent1 == $categoryId ) )             then                         $conf.setSubCategories($subcats); end but it gives me following error. [34,56]: [ERR 101] Line 34:56 no viable alternative at input ')' in rule "select sub categories" in pattern Configuration [34,57]: [ERR 102] Line 34:57 mismatched input '.' expecting ')' in rule "select sub categories" in pattern Configuration [34,74]: [ERR 102] Line 34:74 mismatched input '!=' expecting 'then' in rule "select sub categories" in pattern Configuration Do I need to use “eval” around the “$conf.getCategory().getCategoryId()” part ?  Also in that case how do I get access to the property value ?  It doesn’t support something like this : $conf : Configuration($categoryId : eval( $conf.getCategory().getCategoryId() != null ), subCategories == null  ) Regards, Abhay ________________________________ From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Wendy Mungovan Sent: Tuesday, May 10, 2011 3:31 PM To: Rules Users List Subject: Re: [rules-users] FW: Basic rules question Abhay,   You can use the normal Java gets (if your object has them). when             $prod : Product ($prod.getMemory().getRam().getType() == "DDR") ... instead of $prod.getMemory()... you I think should also be able to use 'this.getMemory()....' (I have not tried these out to make sure) Wendy ________________________________ From: Abhay B. Chaware <Abhay.Chaware(a)kpitcummins.com&gt; To: Rules Users List <rules-users(a)lists.jboss.org&gt; Sent: Mon, May 9, 2011 11:56:42 PM Subject: Re: [rules-users] FW: Basic rules question OK. Another one.  How do I access and use a property of a member variable ( object ) of an object, in rules ? e.g.  in the same example, I need to check 1)  if a product of type ‘laptop’ is inserted in memory AND 2)  if the product’s MEMORY property ( object ) has an object of type DDR ram attached. In other words, here is the relationship of facts - PRODUCT has member variable MEMORY ( which is an object ) MEMORY has member variable RAM ( which is again an object ) RAM has member variable TYPE ( which should be equal to “DDR” ) From within rules ‘when’ part, how do I check if there is a PRODUCT inserted in memory whose MEMORY has a RAM of type DDR assigned ? Regards, Abhay Chaware Sr. Designer | KPIT Cummins Infosystems Ltd | Board: +91 020 6652 5000 | Extn: 2989  | abhay.chaware(a)kpitcummins.com |www.kpitcummins.com P Please consider the environment before printing this e-mail ________________________________ From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Michael Anstis Sent: Monday, May 09, 2011 4:27 PM To: Rules Users List Subject: Re: [rules-users] FW: Basic rules question Yes :) 2011/5/9 Abhay B. Chaware <Abhay.Chaware(a)kpitcummins.com&gt; Mike, What I meant was, There are say 10 objects of RAM in memory whose type is DDR.  Now my “Product” object has a member variable named “compatibleRAMs”, and I would like to set an arraylist containing these 10 objects to the “compatibleRAMs” variable of “Product” object in memory. I am reading about the “collect” which can be used to create collections from fact objects in memory.   Something like. When             $prod : Product (type==’laptop’) $compatibleRAMs : ArrayList() from collect (RAM (type == ‘DDR’)) Then             $prod.setCompatibleRAMs($compatibleRAMs); Am I on the right track ? -abhay ________________________________ From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Michael Anstis Sent: Monday, May 09, 2011 3:52 PM To: Rules Users List Subject: Re: [rules-users] FW: Basic rules question Abhay, Do you need a list? You can assign RAM to COMPUTERS with this:- when     $c : Computer( $type : type )     $r : RAM( compatibleWith == $type ) then    $c.addRAM( $r ); end This would add all RAM (in Working Memory) compatible with COMPUTER to computer. You could use a list of RAM as a Fact in WM and change your rule to use that:- when     $l : MyList( )     $c : Computer( $type : type )     $r : RAM( compatibleWith == $type ) from $l then     $c.addRAM( $r ); end Or you can define a rule to construct the list too:- when     $l : MyList( $t : typeRAM )     RAM( $c : $t ) then     $l.add( $r ) end I assume you'd need to differentiate different lists for different types; so I have shown use of "MyList" which could subclass ArrayList and have a "Type of RAM" attribute. Drools doesn't "do" generics. With kind regards, Mike 2011/5/9 Abhay B. Chaware <Abhay.Chaware(a)kpitcummins.com&gt; Wendy, Thanks for helping me out so far. I have another question. What if I have all my “RAM” objects inserted into working memory.   How should I write my rule’s “when” portion to get a collection of all the RAM objects matching type “DDR” ?  In other words, can I get collection of facts assigned to a variable and use it in the “then” part ? Thanks Abhay ================================== From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Wendy Mungovan Sent: Friday, May 06, 2011 5:47 PM To: Rules Users List Subject: Re: [rules-users] Basic rules question Q2:   So the rule would be something like: rule "RAM type"   when      $product: Product(type == "laptop");  then      //you are looking for the best way to set valid RAM types in the then part of the rule?     $product.setRamType("DDR");     //or    $product.setValidRamOptions( getValidRamOptions("DDR"));  end where getValidRamOptions would be a custom function included through 'import function' so you can then load the choices from some where else.  Or if RamOptions were an object in memory you could have a rule like: rule "RAM type"   when      $product: Product(type == "laptop");      $ramOptions: RAMOptions(type == "DDR");  then    $product.setValidRamOptions( $ramOptions.getList());  end Wendy ================================== Regards, Abhay Chaware Sr. Designer | KPIT Cummins Infosystems Ltd | Board: +91 020 6652 5000 | Extn: 2989  | abhay.chaware(a)kpitcummins.com |www.kpitcummins.com P Please consider the environment before printing this e-mail ________________________________ From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Wendy Mungovan Sent: Friday, May 06, 2011 5:47 PM To: Rules Users List Subject: Re: [rules-users] Basic rules question Abhay,   Q1:  I think that this will depend on how many different products you have.  If there is a small number it is more straight forward to have a rule for each one (so the 2nd option).  This allows all you logic to be in one place.  If there are a large number of products and writing a rule for each one is intractable you probably would want to look into some generalizations of the rules.  Is that helpful?   Q2: I'm not quite sure what you are getting at in Q2.  Are you trying to write validation rules or rules that are modifying the facts? Wendy ________________________________ From: Abhay B. Chaware <Abhay.Chaware(a)kpitcummins.com&gt; To: &quot;rules-users(a)lists.jboss.org&quot; <rules-users(a)lists.jboss.org&gt; Sent: Fri, May 6, 2011 4:59:46 AM Subject: [rules-users] Basic rules question Hi I am a newbie to rule based applications and trying to get the concept of rules. I have couple of questions about rules to start with, not specifically about Drools though. Q1 - Should rules be data/model specific or can/should they be generic or both ========================================================== e.g. If selected product “TYPE” is “laptop”, then category “RAM” should have all “DDR” type items compatible ( selecting items matching certain property ) OR If selected product is “IBM T42”, then category “RAM” should have “512MB DDR” , “1024MB DDR”, “2048MB DDR”  compatible. ( assigning individual items in rules ) OR Combination of both Q2 – How should be the data modeled in above case ========================================================== e.g. in product master, each item ( e.g. T40, T42 ) should have a “TYPE” ( e.g. desktop or laptop ) , all items in category “RAM” should have a “TYPE” ( e.g. DDR ) and then control the assignment of RAM options to the PRODUCT through Rule using “DDR” type ? OR in product master, each item ( e.g. T40, T42 ) should have a “TYPE” ( e.g. desktop or laptop ) , all items in category “RAM”  should have a “compatibleProduct” column ( e.g. desktop or laptop ) and control the assignment of RAM to PRODUCT through “dynamic” rules by selecting all the RAMs by passing the “TYPE” of the product to the database handler. Am I making my point clear ? Thanks Abhay This message contains information that may be privileged or confidential and is the property of the KPIT Cummins Infosystems Ltd. 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If you are not the intended recipient, you are not authorized to read, print, retain copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message. KPIT Cummins Infosystems Ltd. does not accept any liability for virus infected mails. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users