Hi folks, Is it possible to refer to DRL functions from a DRL when the dialect is mvel? I have been working on unit tests for a rule that were consistently failing due to not being able to find the function that should be imported. Having tried various formats (the documentation is rather unhelpful here) for the import, I thought I'd see what happened if I just switched to the Java dialect. Suddenly it worked without even needing an import statement. Unfortunately, this forces me to switch from the neat ... newFact.Property = otherFact.Property ... to the rather ugly Java-style newFact.setProperty(otherFact.getProperty()) So I would quite like to know if there is an undocumented (or well-hidden-documented) mechanism for using functions when in mvel dialect. Or am I stuck with switching to Java? Thanks in advance for any pointers anybody can provide, Steve

Okay Wolfgang ... you asked for it. Here's a version which takes it pretty much to the minimum. The error I see is "Unable to resolve method using strict-mode: mypackage.CloneMessage.cloneMessage(mypackage.Message)" However, the error is only seen when I use mvel dialect. The working Java dialect rule is also included below. Note that when I re-wrote the example function to take a common type such as String as argument, then the mvel version worked. It's when the argument is a declared type that it fails. Thanks for taking a look, Steve file - MessageFact.drl package mypackage declare Message Text: String end file - CloneMessage.drl package mypackage function Message cloneMessage(Message originalMessage) { Message newMessage = new Message(); newMessage.setText(originalMessage.getText()); return newMessage; } file - SayHelloRuleJava.drl package mypackage rule "Say hello" dialect "java" lock-on-active true when # Always then Message originalMessage = new Message(); originalMessage.setText("Hello, World!"); Message clonedMessage = cloneMessage(originalMessage); insert(clonedMessage); end file - SayHelloRuleMvel.drl package mypackage rule "Say hello" dialect "mvel" lock-on-active true when # Always then Message originalMessage = new Message(); originalMessage.Text = "Hello, World!"; Message clonedMessage = cloneMessage(originalMessage); insert(clonedMessage); end On Jun 19, 2012, at 12:27 PM, Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; wrote: Can you please provide an example where and how you import and use a DRL function so that it works/doesn't work with MVEL/Java? -W On 19/06/2012, Stephen Masters <stephen.masters(a)me.com&gt; wrote: > Hi folks, > > Is it possible to refer to DRL functions from a DRL when the dialect is > mvel? > > I have been working on unit tests for a rule that were consistently > failing > due to not being able to find the function that should be imported. Having > tried various formats (the documentation is rather unhelpful here) for the > import, I thought I'd see what happened if I just switched to the Java > dialect. Suddenly it worked without even needing an import statement. > > Unfortunately, this forces me to switch from the neat ... > newFact.Property = otherFact.Property > ... to the rather ugly Java-style > newFact.setProperty(otherFact.getProperty()) > > So I would quite like to know if there is an undocumented (or > well-hidden-documented) mechanism for using functions when in mvel > dialect. > Or am I stuck with switching to Java? > > Thanks in advance for any pointers anybody can provide, > > Steve _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

My understanding from the docs is that the DRL functions are converted into helper classes, which can be imported with "import function mypackage.CloneMessage.cloneMessage", although it's not clear what that 'class name' (?) in the middle refers to. Maybe the generated helper class? However, if the function is in your current package the import is automatically derived for you. Hence no import statements in my tests. Which is nice. :) I just tried combining them in a single file, and it still fails for the same reason. I'm still on 5.3.1 at the moment, so I think this might be a new item for my list of reasons to roll up my sleeves and upgrade. Thanks for taking a look, Steve On Jun 19, 2012, at 01:42 PM, Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; wrote: It works (5.4.0) with both, Java and MVEL, if all is in the same DRL file. I'm somewhat surprised that "import" should work for DRL functions, but I may have missed some development. But your snippets don't show a DRL import statement? -W On 19/06/2012, Stephen Masters <stephen.masters(a)me.com&gt; wrote: > Okay Wolfgang ... you asked for it. Here's a version which takes it pretty > much to the minimum. > > The error I see is "Unable to resolve method using strict-mode: > mypackage.CloneMessage.cloneMessage(mypackage.Message)" > > However, the error is only seen when I use mvel dialect. The working Java > dialect rule is also included below. > > Note that when I re-wrote the example function to take a common type such > as > String as argument, then the mvel version worked. It's when the argument > is > a declared type that it fails. > > Thanks for taking a look, > > Steve > > > > file - MessageFact.drl > > package mypackage > > declare Message > Text: String > end > > > > file - CloneMessage.drl > > package mypackage > > function Message cloneMessage(Message originalMessage) { > > Message newMessage = new Message(); > newMessage.setText(originalMessage.getText()); > return newMessage; > > } > > > > file - SayHelloRuleJava.drl > > package mypackage > > rule "Say hello" > dialect "java" > lock-on-active true > when > # Always > then > Message originalMessage = new Message(); > originalMessage.setText("Hello, World!"); > > Message clonedMessage = cloneMessage(originalMessage); > > insert(clonedMessage); > end > > > > file - SayHelloRuleMvel.drl > > package mypackage > > rule "Say hello" > dialect "mvel" > lock-on-active true > when > # Always > then > Message originalMessage = new Message(); > originalMessage.Text = "Hello, World!"; > > Message clonedMessage = cloneMessage(originalMessage); > > insert(clonedMessage); > end > > > > On Jun 19, 2012, at 12:27 PM, Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; > wrote: > > Can you please provide an example where and how you import and use a > DRL function so that it works/doesn't work with MVEL/Java? > > -W > > > On 19/06/2012, Stephen Masters <stephen.masters(a)me.com&gt; wrote: >> Hi folks, >> >> Is it possible to refer to DRL functions from a DRL when the dialect is >> mvel? >> >> I have been working on unit tests for a rule that were consistently >> failing >> due to not being able to find the function that should be imported. >> Having >> tried various formats (the documentation is rather unhelpful here) for >> the >> import, I thought I'd see what happened if I just switched to the Java >> dialect. Suddenly it worked without even needing an import statement. >> >> Unfortunately, this forces me to switch from the neat ... >> newFact.Property = otherFact.Property >> ... to the rather ugly Java-style >> newFact.setProperty(otherFact.getProperty()) >> >> So I would quite like to know if there is an undocumented (or >> well-hidden-documented) mechanism for using functions when in mvel >> dialect. >> Or am I stuck with switching to Java? >> >> Thanks in advance for any pointers anybody can provide, >> >> Steve > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users