[rules-users] FW: Basic rules question

Tue May 10 06:01:17 EDT 2011

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 at kpitcummins.com>
To: Rules Users List <rules-users at lists.jboss.org>
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,

________________________________

From:rules-users-bounces at lists.jboss.org 
[mailto:rules-users-bounces at 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 at kpitcummins.com>
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 at lists.jboss.org 
[mailto:rules-users-bounces at 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 at kpitcummins.com>

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 at lists.jboss.org 
[mailto:rules-users-bounces at 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,

________________________________

From:rules-users-bounces at lists.jboss.org 
[mailto:rules-users-bounces at 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 at kpitcummins.com>
To: "rules-users at lists.jboss.org" <rules-users at lists.jboss.org>
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. It is intended only for the 
person to whom it is addressed. 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 at lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users

This message contains information that may be privileged or confidential and is 
the property of the KPIT Cummins Infosystems Ltd. It is intended only for the 
person to whom it is addressed. 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 at lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users

This message contains information that may be privileged or confidential and is 
the property of the KPIT Cummins Infosystems Ltd. It is intended only for the 
person to whom it is addressed. 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. 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20110510/0eda7bdb/attachment.html 