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Questions tagged [rule-engine]

Rule engines are software components that allow application developers to externalize business rules and manage their lifecycle independently from the application code.

Rule engines

Rule engines are software components that allow application developers to externalize business rules and manage their lifecycle independently from the application code. They typically use a higher level declarative language (in contrast to the typical imperative paradigm of languages like Java and C++) and use specific algorithms for scalability and high performance. A good analogy is that Rule Engines do for business rules what databases do for data.

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How to implement a rule engine?

I have a db table that stores the following: RuleID objectProperty ComparisonOperator TargetValue 1 age 'greater_than' 15 2 username 'equal' 'some_name' 3 tags 'hasAtLeastOne' …
Blankman
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Pros and cons of Java rules engines

What are the pros and cons to adopting the Java rules engines JESS and Drools? Are there any other players? I understand that Drools is Open Source and JESS is not, but how do they compare in other areas like ease of use, performance, level of…
brabster
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When should you NOT use a Rules Engine?

I have a pretty decent list of the advantages of using a Rules Engine, as well as some reasons to use them, what I need is a list of the reasons why you should NOT use a Rules Engine The best I have so far is this: Rules engines are not really…
BlackTigerX
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Rules Engine - pros and cons

I'm auditing a project that uses what is called a Rules Engine. In short, it's a way to externalize business logic from application code. This concept is entirely new to me and I'm pretty skeptical about it. After hearing people talk about Anemic…
bpapa
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Looking for simple rules-engine library in .NET

Does anyone know of a good .NET library rules library (ideally open-source)? I need something that can do nested logic expressions, e.g., (A AND B) AND (B OR C OR D). I need to do comparisons of object properties, e.g., A.P1 AND B.P1. (Ideally, I…
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Lightweight Rules Engine in Javascript

I am looking for suggestions for a lightweight rules engine implemented in Javascript. The reason for such an implementation is to build a very lightweight but fast browser-based simulation using a small set of rules (less than 20). The simulation…
Philippe Monnet
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creating a simple rule engine in java

I am exploring different ways to create a simple business rule engine in Java. I need to present the client with a simple webapp that lets him configure a bunch of rules. A sample of rule base might look like this : Here's example: IF (PATIENT_TYPE…
Jay
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Design Pattern to implement Business Rules with hundreds of if else in java

I have to implement certain business rules with hundreds of lines of below code: if this then this else if then this . . // hundreds of lines of rules else that Do we have any design pattern which can effectively implement this…
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Is there any rules engine implemented on NodeJS / in Javascript?

I need a lightweight rules engine. We have around 50 rules right now, but the rules keep changing frequently. We could use Drools, but I figure that would be overkill. Are there any lighter, F/OSS implementations? I am aware of the other similar…
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Why should i use Drools?

I am no Drools expert. I have some familiarity with it though, by experimenting with it. I am unable to appreciate, why would i need it. My Typical Applications are Business Web Applications. Yes they do have some amount of Rules. But those are…
Jasper
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Python Rule Based Engine

I am looking to design a system that will essentially need to make decisions based on input. The input will be a person. class Person: def __init__(self, name, age, sex, weight, height, nationality): self.name = name self.age =…
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Rule Engine in JavaScript

Is there any Rule engine in JavaScript? The question is in this context: Consider a web application having a form that users fill up. As a user fills up each field and proceeds to the next, business logic written in JavaScript controls the…
Pradyumna
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managing complex web forms

I work on an application, the core of which is a very complex set of web forms. The source of this complexity scale, some forms contain about 50 pages, which up to 30 questions on each page complex rules, e.g. if the user answers "no" to question…
Dónal
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Drools- how to find out which all rules were matched?

I've one .DRL file which has say 10 rules. Once I insert a fact, some rules may be matched- how do I find out which rules were matched programmatically?
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I need a simple rules engine, I think?

I need some advice on the best approach to solving this problem. I've researched DROOLS, Java Rule Engine and a few others. All of these are powerful, and have good things about them. I don't know which (if any) will be the best choice for me. I…
Andy
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