cluster/go-ruler

basic rules engine for go

go-ruler

json-y object testing in go

Installation

go get github.com/hopkinsth/go-ruler

Introduction

go-ruler is an implementaion of ruler in go, partly as an experiment, eventually as an optimization strategy. go-ruler supports programmatically constructing rules in a way similar to js-ruler and can also process rules stored in arrays of JSON objects with this structure:

{
  "comparator": "eq",
  "path": "library.name",
  "value": "go-ruler"
}

Each of those objects (or 'filters') describes a condition for a property on some JSON object or json-object-esque structure. (In this go implementation, we're using map[string]interface{}.)

Example

package main

import "github.com/hopkinsth/go-ruler"
import "fmt"

func main() {
  rules := []byte(`[
    {"comparator": "eq", "path": "library.name", "value": "go-ruler"},
    {"comparator": "gt", "path": "library.age", "value": 0.5}
  ]`)

  // supports loading rules from JSON data
  engine, _ := ruler.NewRulerWithJson(rules)

  // can also build rules programmatically
  engine = ruler.NewRuler()
  engine.Rule("library.name").
    Eq("go-ruler").
    End().
  Rule("library.age").
    Gt(0.5)

  result := engine.Test(map[string]interface{}{
    "library": map[string]interface{}{
      "name": "go-ruler",
      "age":  1.24,
    },
  })

  fmt.Println(result == true)
}

License

Copyright 2015 Thomas Hopkins

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with the License. You may obtain a copy of the License in the LICENSE file, or at:

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.