diff --git a/src/almanac.js b/src/almanac.js
index 7a9a8e0..ccf684c 100644
--- a/src/almanac.js
+++ b/src/almanac.js
@@ -4,12 +4,8 @@ import Fact from './fact'
import { UndefinedFactError } from './errors'
import debug from './debug'
-import { JSONPath } from 'jsonpath-plus'
import isObjectLike from 'lodash.isobjectlike'
-
-function defaultPathResolver (value, path) {
- return JSONPath({ path, json: value, wrap: false })
-}
+import { defaultPathResolver } from './resolver';
/**
* Fact results lookup
diff --git a/src/engine.js b/src/engine.js
index 3bd958e..6775113 100644
--- a/src/engine.js
+++ b/src/engine.js
@@ -7,6 +7,8 @@ import Almanac from './almanac'
import EventEmitter from 'eventemitter2'
import defaultOperators from './engine-default-operators'
import debug from './debug'
+import { interpolateDeep, needsInterpolation, defaultInterpolation } from './interpolate';
+import { defaultPathResolver } from './resolver';
export const READY = 'READY'
export const RUNNING = 'RUNNING'
@@ -21,12 +23,16 @@ class Engine extends EventEmitter {
super()
this.rules = []
this.allowUndefinedFacts = options.allowUndefinedFacts || false
- this.pathResolver = options.pathResolver
+ this.pathResolver = options.pathResolver || defaultPathResolver
+ this.interpolation = options.interpolation || defaultInterpolation;
+ if(!(this.interpolation instanceof RegExp) || !this.interpolation.global) throw new Error('interpolation option must be a global regexp')
this.operators = new Map()
this.facts = new Map()
this.status = READY
rules.map(r => this.addRule(r))
defaultOperators.map(o => this.addOperator(o))
+
+ this.interpolatableRules = new Set();
}
/**
@@ -49,6 +55,7 @@ class Engine extends EventEmitter {
if (!Object.prototype.hasOwnProperty.call(properties, 'conditions')) throw new Error('Engine: addRule() argument requires "conditions" property')
rule = new Rule(properties)
}
+ if(needsInterpolation(rule,this.interpolation)) this.interpolatableRules.add(rule);
rule.setEngine(this)
this.rules.push(rule)
this.prioritizedRules = null
@@ -62,7 +69,8 @@ class Engine extends EventEmitter {
updateRule (rule) {
const ruleIndex = this.rules.findIndex(ruleInEngine => ruleInEngine.name === rule.name)
if (ruleIndex > -1) {
- this.rules.splice(ruleIndex, 1)
+ const [old] = this.rules.splice(ruleIndex, 1)
+ this.interpolatableRules.delete(old);
this.addRule(rule)
this.prioritizedRules = null
} else {
@@ -75,21 +83,25 @@ class Engine extends EventEmitter {
* @param {object|Rule|string} rule - rule definition. Must be a instance of Rule
*/
removeRule (rule) {
- let ruleRemoved = false
+ let theRemovedRule;
if (!(rule instanceof Rule)) {
- const filteredRules = this.rules.filter(ruleInEngine => ruleInEngine.name !== rule)
- ruleRemoved = filteredRules.length !== this.rules.length
+ const filteredRules = this.rules.filter(ruleInEngine => {
+ const isRule = ruleInEngine.name === rule;
+ if(!theRemovedRule && isRule) theRemovedRule = ruleInEngine;
+ return !isRule;
+ });
this.rules = filteredRules
} else {
const index = this.rules.indexOf(rule)
if (index > -1) {
- ruleRemoved = Boolean(this.rules.splice(index, 1).length)
+ theRemovedRule = this.rules.splice(index, 1)[0];
}
}
- if (ruleRemoved) {
+ if (theRemovedRule) {
this.prioritizedRules = null
+ this.interpolatableRules.delete(theRemovedRule);
}
- return ruleRemoved
+ return Boolean(theRemovedRule);
}
/**
@@ -211,6 +223,7 @@ class Engine extends EventEmitter {
debug(`engine::run status:${this.status}; skipping remaining rules`)
return Promise.resolve()
}
+
return rule.evaluate(almanac).then((ruleResult) => {
debug(`engine::run ruleResult:${ruleResult.result}`)
almanac.addResult(ruleResult)
@@ -240,12 +253,28 @@ class Engine extends EventEmitter {
pathResolver: this.pathResolver
}
const almanac = new Almanac(this.facts, runtimeFacts, almanacOptions)
- const orderedSets = this.prioritizeRules()
+ const orderedSets = this.prioritizeRules();
+
let cursor = Promise.resolve()
// for each rule set, evaluate in parallel,
// before proceeding to the next priority set.
return new Promise((resolve, reject) => {
orderedSets.map((set) => {
+ set = set.map(rule => {
+ if(!this.interpolatableRules.has(rule)) return rule;
+ rule = new Rule(
+ interpolateDeep(
+ rule.toJSON(true),
+ runtimeFacts,
+ this.interpolation,
+ this.pathResolver
+ )
+ );
+ rule.setEngine(this);
+ return rule;
+ });
+
+
cursor = cursor.then(() => {
return this.evaluateRules(set, almanac)
}).catch(reject)
diff --git a/src/interpolate.js b/src/interpolate.js
new file mode 100644
index 0000000..93ffea7
--- /dev/null
+++ b/src/interpolate.js
@@ -0,0 +1,27 @@
+export const defaultInterpolation = /\{\{\s*(.+?)\s*\}\}/g
+
+export const needsInterpolation = (rule,regexp) => regexp.test(rule.toJSON(true));
+
+const interpolate = (subject = '', params = {}, regexp, resolver) => {
+ let shouldReplaceFull, found;
+
+ const replaced = subject.replace(regexp, (full, matched) => {
+ shouldReplaceFull = full === subject;
+ found = resolver(params, matched);
+ return shouldReplaceFull ? '' : found;
+ });
+
+ return shouldReplaceFull ? found : replaced;
+};
+
+
+export const interpolateDeep = (o, params, regexp, resolver) => {
+ if (!o || typeof o === 'number' || typeof o === 'boolean') return o;
+
+ if (typeof o === 'string') return interpolate(o,params,regexp,resolver)
+
+ if (Array.isArray(o)) return o.map(t => interpolateDeep(t, params, regexp, resolver));
+
+ return Object.entries(o).reduce((acc, [k, v]) => ({...acc,[k]: interpolateDeep(v, params, regexp, resolver)}),{});
+};
+
diff --git a/src/resolver.js b/src/resolver.js
new file mode 100644
index 0000000..fd41455
--- /dev/null
+++ b/src/resolver.js
@@ -0,0 +1,5 @@
+import { JSONPath } from 'jsonpath-plus'
+
+export function defaultPathResolver (value, path) {
+ return JSONPath({ path, json: value, wrap: false })
+}
\ No newline at end of file
diff --git a/src/rule.js b/src/rule.js
index 5db0191..afaf322 100644
--- a/src/rule.js
+++ b/src/rule.js
@@ -4,6 +4,7 @@ import Condition from './condition'
import RuleResult from './rule-result'
import debug from './debug'
import EventEmitter from 'eventemitter2'
+import { needsInterpolation } from './interpolate'
class Rule extends EventEmitter {
/**
diff --git a/test/engine-fact.test.js b/test/engine-fact.test.js
index 93d9b99..5822d10 100644
--- a/test/engine-fact.test.js
+++ b/test/engine-fact.test.js
@@ -61,12 +61,15 @@ describe('Engine: fact evaluation', () => {
operator: 'lessThan',
params: {
eligibilityId: 1,
- field: 'age'
+ field: '{{whichField}}'
},
value: 50
}]
}
}
+ const runtimeFacts = {
+ whichField:'age'
+ }
let successSpy
let failureSpy
beforeEach(() => {
@@ -94,7 +97,7 @@ describe('Engine: fact evaluation', () => {
value: true
})
setup(conditions)
- return expect(engine.run()).to.be.rejectedWith(/Undefined fact: undefined-fact/)
+ return expect(engine.run(runtimeFacts)).to.be.rejectedWith(/Undefined fact: undefined-fact/)
})
context('treats undefined facts as falsey when allowUndefinedFacts is set', () => {
@@ -106,7 +109,7 @@ describe('Engine: fact evaluation', () => {
value: true
})
setup(conditions, { allowUndefinedFacts: true })
- await engine.run()
+ await engine.run(runtimeFacts)
expect(successSpy).to.have.been.called()
expect(failureSpy).to.not.have.been.called()
})
@@ -131,7 +134,7 @@ describe('Engine: fact evaluation', () => {
describe('params', () => {
it('emits when the condition is met', async () => {
setup()
- await engine.run()
+ await engine.run(runtimeFacts)
expect(successSpy).to.have.been.calledWith(event)
})
diff --git a/test/engine.test.js b/test/engine.test.js
index 6030466..34b8b3b 100644
--- a/test/engine.test.js
+++ b/test/engine.test.js
@@ -3,6 +3,7 @@
import sinon from 'sinon'
import engineFactory, { Fact, Rule, Operator } from '../src/index'
import defaultOperators from '../src/engine-default-operators'
+import Condition from '../src/condition'
describe('Engine', () => {
const operatorCount = defaultOperators.length
@@ -92,8 +93,7 @@ describe('Engine', () => {
engine.addRule(rule2)
expect(engine.rules[0].conditions.all.length).to.equal(2)
expect(engine.rules[1].conditions.all.length).to.equal(2)
-
- rule1.conditions = { all: [] }
+ rule1.conditions = new Condition({all:[]})
engine.updateRule(rule1)
rule1 = engine.rules.find(rule => rule.name === 'rule1')
diff --git a/types/index.d.ts b/types/index.d.ts
index b3d39e2..25b1072 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -1,6 +1,7 @@
export interface EngineOptions {
allowUndefinedFacts?: boolean;
pathResolver?: PathResolver;
+ interpolation?: RegExp;
}
export interface EngineResult {