Viya.RuleEngine 0.4.1

RuleEngine

With RuleEngine you can write rules, which consist of an expression and a patch definition, to modify a object/model.

These rules can be defined in yaml or with typed C# objects.

Release Notes

Please see the changelog!

Example

Provided the following input object

Name: Henk
Age: 15
Phone: 0612345678
Address:
  StreetName: Hoofdstraat
  StreetNumber: 25a
  City: Amsterdam
  PostalCode: 1234AA
WorkAddress: null # Same type/fields as Address

Replacing a single property

rules:
  - condition: Age < 16
    patch:
      Age: 25

The condition Age < 16 evaluates to: true
Thus the Age property becomes: 25

Replacing multiple properties at once (merge)

rules:
  - condition: Phone.StartsWith("06")
    patch:
      Phone: 0612341234
      Address:
        City: Hilversum

The condition Phone.StartsWith("06") evaluates to: true
Thus the Phone property becomes 0621341234 and Address.City becomes Hilversum

Using lambda expressions in assignments

With a Lambda expression it is possible to use logic to assign the object, take a look at the following examples.

patch:
  myProperty1: input => input.Name              # referencing the input object
  myProperty2: x => $"prefix-{x.Name}-postfix"  # using a custom identifier with string interpolation
  myYear: _ => DateTime.Now.Year                # omitting the input object and using DateTime C# class  

Copy-ing properties from the input object

rules:
  - condition: true
    patch: # copy to child object (not null) 
      WorkAddress: input => input.Address

Here the condition is true
The result becomes:

Name: Henk
Age: 15
Phone: 0612345678
Address:
  StreetName: Hoofdstraat
  StreetNumber: 25a
  City: Amsterdam
  PostalCode: 1234AA
WorkAddress:
  StreetName: Hoofdstraat
  StreetNumber: 25a
  City: Amsterdam
  PostalCode: 1234AA

Finding the best tool for the job

Running a benchmark

dotnet run -c Release --project RuleEngine.Benchmark

Results:

• Patching objects
• Expression evaluation

Resources

All this was not possible without the following libraries:

• ExpressionEvaluator
• Newtonsoft.Json