Question

I have requirement to build new rule engine in which i have rule like this which is stored in Excel sheet, in tabular format.

<If>  'Name = Nita ' <Value> '200' <else> 'Name = Gita' <value> '300' <LookInto> '/Name/@Income' 

I have two files say 1 n 2. i need to see in first file that whether Name is Nita or Gita. Based on execution i will get value. Now this result value i need to compare with second file , which is a xml file and whose path has been defined into .

can anybody suggest me that is there anything in C# that i can use effectively to develop the same,, or can anybody suggest me how i can achieve this with C#.. i need some idea for class design of the same.

I am using .Net 1.1.

Answer 1

Firstly, you need to create classes that can define your rules. Once you have this structure in place, you will be able to build an engine that utilises those classes.

I would look at creating something like:

class RuleEngine  {   public RuleMatch[] RuleMatches { get; set; }   public void RunEngine(inputdata...)    {       // do processing in here   } }  class RuleMatch  {   public Rule[] Rules { get; set; }   public Object ValueIfMatched { get; set; } }  class Rule  {   public String FieldName { get; set; }   public MatchType Match { get; set; }   public Object Value { get; set; } )  enum MatchType  {   Equal = 1,   NotEqual = 2,   GreaterThan = 4,   LessThan = 8,   Like = 16 } 

Then go on from there….

This structure would be better if it was changed to have a group of rules that could be added to a group of rules, for example (a AND b) OR (c AND d) – I’ll leave this to you to think about for now.

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Please note I’m using some C# 3.0 constructs here, you will need to create full private properties in 1.1.