Thanks for your mail. I am very (very) intrigued by this project - I am currently reading through the materials on the dark-matter-project wiki to see if i can use it. Nevertheless, it is very exciting to say the least - evidently. you have done a lot of work on this.
Just so we are on the same page - let me re-iterate what I am trying to do - with an example Example -> I see you have mentioned eclipse modeling framework in the dark-matter-project wiki. I don't know whether you have worked with the eclipse Graphical Modeling framework (GMF) - in GMF you can launch a cheat-sheet called GMF Dashboard which guides you through the process Here is a video - http://www.youtube.com/watch?v=JbnqEA0dLTk - appears in the bottom part of the editor around 2:17 mins. As you can see, the GMF Dashboard is basically a visual representation of a workflow+rules+state-engine pattern with defined user-action and app-action at each state. The user can go through the workflow working on any state - the state machine pattern of the gine. However, there are certain rules applied - like a certain dependent state can only be activated when all the previous state has been completed - the workflow part of the engine. At each state, when the user provides certain inputs, the input ( in this case - domain model etc) is validated and the app takes a pre-defined action based on the rules (like generating code etc)- hence the rules part of engine My case -> Very similar to the above ( only i am thinking of implementing the graphical part as a 2nd step). As of now, the design is as follows The whole process is a logic/algorithm working on user provided data. Which part of the algorithm is triggered depends on what data the user provides. 1> The user triggers any of the defined workflow 2>. The work flow has a specific defined path / states and the user can not go a dependent state without completing previous states 3>. The user can go back to any state which he has executed and edit it again. 4>. At each state as the user enter the data, the rules engine validates it - it might also alter the defined path depending on the data. A point which I am still trying to figure out in the dark-matter-project - it looks to be more of a compile time creation of class - and I am still trying to figure out how to achieve #2 above with it. On Saturday, August 24, 2013 8:56:39 PM UTC-4, Sleeveen wrote: > > I have something very similar to what you're describing, but it depends on > a complete infrastructure of generated code; the dark-matter-data project > (in Google Code). > > Classes and attributes are modelled and the generated (fully GWT > compliant) classes lend themselves to being sanity checked, and or having > business rules applied to them. > > The rules themselves are modelled and allow for parameterizing instances > of the rules. > > For instance, let's say you have a class X with a numeric attribute > myValue that you want limited to a range of values. You would specify (as > part of the schema that defines your classes): > > NumericRangeRuleData > ruleName Limit myValue to 1-15 > nrrMinimum 1 > nrrMaximum 15 > applyToAttribute myValue > applyToClass X > > At runtime, you tell a RuleManager to load the rules from the schema of > the classes you're dealing with. > > You call on the RuleManager to apply the attribute level validation rules > on your object and it determines which set of rules to apply, based on the > applyToClass and applyToAttribute in the rule. > > Different categories of rules are supported, since rules applied in > different contexts require different interfaces to trigger them. Attribute > level rules apply to a single object. Rules that involve consistency > between objects require handles to the objects involved (or to a collection > objects) etc. > > The nice thing about this framework is that you can implement any type of > rule or business logic you need because the implementation is just Java. > > I've been working on dark-matter for about 4 years and it forms the basis > of the network management system my group is working on; my employer was > kind enough to allow to me continue working on it (since I had started it > before joining the company). > > The only problem is that I haven't had the time to put in on the > documentation (my employer wants me focussed on my day job ;-) > > Anyway, if any of this intrigues you, I could work up an example and you > might be able to create your own mechanisms based on the concepts. > > The dark-matter stuff allows us to generate about 80% of our code for both > server and client, so the infrastructure on which the rules stuff depends > is fairly extensive (just so you know). > > Cheers! > > > On Friday, August 9, 2013 9:38:21 AM UTC-4, asif...@gmail.com wrote: >> >> Hi, >> >> The architecture and requirement is as follows >> >> 1>. The application has an extensive domain model and significant amount >> of business logic >> 2>. At runtime, the user populates data in the domain model. >> 3>. "The rules engine" evaluates the data and takes various actions >> including >> a>. Change subsequent data entry forms and data entry process >> flows >> b>. Pops up ui errors. >> >> Since, I don't want to undergo the cost of server roundtrip for each >> evaluation, I am looking for a good architecture or pre-built client side >> rules engine. >> >> In the threads, I came across >> 1>. Jess >> 2>. MVEL >> 3>. Tohu >> 4>. Metawidget >> >> A brief browse, and I have a feeling that MVEL would be the way to go. >> Tohu is kind of ruled out for the same reason that I steered clear of >> Drools/jBPM. >> >> Any expert ideas? Anybody else has attempted anything similar - would >> love to get their view. >> >> Regards >> > -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. 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