disable transforms by default. Enable by calling enable()

.gitignore

@@ -18,3 +18,4 @@ dist/
 *.ps
 *.toc
 *.gz
+index.html

models/core.js

@@ -1,7 +1,9 @@
 module.exports = [
   "conceptualise an ~ entity ~ E",
+  "conceptualise a ~ transform ~ T that has the value W as ~ output ~ and has the value F as ~ transform function ~",
+  "conceptualise a ~ transformer ~ T that ~ uses ~ the transform U",
   "conceptualise an ~ imageable thing ~ I that has the value V as ~ image ~",
-  "conceptualise a ~ timestamp ~ T that is an entity",
+  "conceptualise a ~ timestamp ~ T that is a transformer and has the value V as ~ date ~",
   "conceptualise an ~ agent ~ A that is an entity and has the value V as ~ address ~",
   "conceptualise an ~ individual ~ I that is an ~ agent ~",
   "conceptualise a ~ card ~ C that is an entity and has the timestamp T as ~ timestamp ~ and has the value V as ~ content ~ and has the value W as ~ linked content ~ and has the value V as ~ number of keystrokes ~ and has the timestamp T as ~ start time ~ and has the value W as ~ submit time ~ and has the value L as ~ latitude ~ and has the value M as ~ longitude ~",
@@ -21,5 +23,6 @@ module.exports = [
   "conceptualise a ~ listen policy ~ P that is a policy",
   "conceptualise a ~ listen onbehalfof policy ~ P that is a policy",
   "conceptualise a ~ forwardall policy ~ P that is a policy and has the timestamp T as ~ start time ~ and has the value V as ~ all agents ~",
-  "conceptualise a ~ feedback policy ~ P that is a policy and has the value V as ~ acknowledgement ~"
+  "conceptualise a ~ feedback policy ~ P that is a policy and has the value V as ~ acknowledgement ~",
+  "conceptualise a ~ transform policy ~ P that is a policy and has the value V as ~ transform type ~ and ~ uses ~ the transform U"
 ];

src/CEInstance.js

@@ -158,6 +158,7 @@ class CEInstance {
       if (propagate !== false) {
         this.node.ruleEngine.enactRules(this, 'value', valueInstance, source);
       }
+      this.node.transformEngine.enactTransforms(this, label, valueInstance, source);
     }
     return null;
   }
@@ -197,6 +198,7 @@ class CEInstance {
       if (propagate !== false) {
         this.node.ruleEngine.enactRules(this, 'relationship', relationshipInstance, source);
       }
+      this.node.transformEngine.enactTransforms(this, label, relationshipInstance, source);
     }
     return null;
   }

src/CENode.js

@@ -21,6 +21,7 @@ const CEParser = require('./CEParser.js');
 const QuestionParser = require('./QuestionParser.js');
 const NLParser = require('./NLParser.js');
 const RuleEngine = require('./RuleEngine.js');
+const TransformEngine = require('./TransformEngine.js');
 
 class CENode {
 
@@ -248,6 +249,7 @@ class CENode {
     this.questionParser = new QuestionParser(this);
     this.nlParser = new NLParser(this);
     this.ruleEngine = new RuleEngine(this);
+    this.transformEngine = new TransformEngine(this);
     this.concepts = [];
     this.instances = [];
     this.conceptDict = {};

src/CEParser.js

@@ -151,7 +151,7 @@ class CEParser {
     instance.sentences.push(t);
 
     const remainder = t.replace(/^there is an? (?:[a-zA-Z0-9 ]*) named (?:[a-zA-Z0-9_]*|'[a-zA-Z0-9_ ]*') that/, '');
-    const facts = remainder.replace(/\band\b/g, '+').match(/(?:'(?:\\.|[^'])*'|[^+])+/g);
+    const facts = remainder.replace(/\band\b/g, '!+').match(/(?:'(?:\\.|[^'])*'|[^!+])+/g);
     for (const fact of facts) {
       this.processInstanceFact(instance, fact, source);
     }
@@ -189,7 +189,7 @@ class CEParser {
     const tokens = t.split(' ');
     tokens.splice(0, 1 + concept.name.split(' ').length + instanceName.split(' ').length);
     const remainder = tokens.join(' ');
-    const facts = remainder.replace(/\band\b/g, '+').match(/(?:'(?:\\.|[^'])*'|[^+])+/g);
+    const facts = remainder.replace(/\band\b/g, '!+').match(/(?:'(?:\\.|[^'])*'|[^!+])+/g);
     if (facts) {
       for (const fact of facts) {
         this.processInstanceFact(instance, fact, source);
@@ -199,7 +199,7 @@ class CEParser {
   }
 
   processInstanceFact(instance, fact, source) {
-    const input = fact.trim().replace(/\+/g, 'and');
+    const input = fact.trim().replace(/!\+/g, 'and');
     if (input.match(/^(?!has)([a-zA-Z0-9 ]*) the ([a-zA-Z0-9 ]*) ([a-zA-Z0-9_' ]*)/)) {
       const re = /^(?!has)([a-zA-Z0-9 ]*) the ([a-zA-Z0-9 ]*) ([a-zA-Z0-9_' ]*)/;
       const match = re.exec(input);

src/PolicyHandler.js

@@ -213,7 +213,17 @@ class PolicyHandler {
           }
         }
       },
-    };
+
+      'transform policy': (policy) => {
+        if (policy.transform_type && policy.uses){
+          for (const instance of this.node.getInstances(policy.transform_type)) {
+            if (!instance.uses) {
+              instance.addRelationship('uses', policy.uses, true); 
+            }
+          }
+        }
+      }
+    }
   }
 
   handle(policy) {

src/TransformEngine.js

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2017 W.M. Webberley & A.D. Preece (Cardiff University)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License 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.
+ *
+ */
+'use strict';
+
+class TransformEngine {
+
+  enable () {
+    this.enabled = true;
+  }
+
+  disable () {
+    this.enabled = false;
+  }
+
+  evaluate (instance, func) {
+    if (!this.enabled) {
+      return 'Transforms disabled';
+    }
+    if (func.indexOf('require') > -1){
+      return 'Invalid function';
+    }
+
+    try {
+      const sandbox = {
+        name: instance.name,
+        type: instance.concept.name
+      };
+      for (const attr of instance.values.concat(instance.relationships)) {
+        const value = attr.instance.name ? attr.instance.name : attr.instance;
+        sandbox[attr.label.toLowerCase().replace(/ /g, '_').replace(/'/g, '')] = value;
+      }
+      if (typeof window !== 'undefined' && window.document) {
+        return function () {
+          return eval(func);
+        }.call(sandbox);
+      } 
+      else {
+        const vm = require('vm');
+        const script = new vm.Script(func);
+        const context = new vm.createContext(sandbox);
+        return script.runInContext(context, {timeout: 30});
+      }
+    }
+    catch (err){
+      return err;
+    }
+  }
+
+  enactTransforms(instance, label, targetInstance, source) {
+    let doTransform = false;
+    let transforms = [];
+
+    // Find out if the target property is a transform
+    if (targetInstance.concept && targetInstance.concept.name === 'transform'){
+      transforms = [targetInstance];
+    }
+
+    // Otherwise check if the 'label' is a dependency of any existing transforms on this instance
+    else {
+      const newLabel = 'this.' + label.toLowerCase().replace(/ /g, '_').replace(/'/g, '');
+      for (const rel of instance.relationships){
+        if (rel.instance.concept && rel.instance.concept.name === 'transform' && rel.instance.transform_function && rel.instance.transform_function.indexOf(newLabel) > -1){
+          transforms.push(rel.instance);
+        }
+      }
+    }
+
+    for (const transform of transforms) {
+      const e = this.evaluate(instance, transform.transform_function);
+      if (e){
+        instance.addValue(transform.output, e.toString(), true, source);
+      }
+    }
+  }
+
+  constructor(node) {
+    this.node = node;
+    this.enabled = false;
+  }
+}
+module.exports = TransformEngine;

test/CEParser.js

@@ -150,6 +150,38 @@ describe('CEParser', function() {
       expect(node.instances.betty_hughes.lives_in.name).to.be('Camden');
       expect(node.instances.sally.lives_in.name).to.be('Kensington and Chelsea');
     });
+
+    it('allow for transforms', () => {
+      node = new CENode(CEModels.core);
+      node.addCE('conceptualise a ~ person ~ P that is a transformer and has the value A as ~ first name ~ and has the value B as ~ last name ~ and has the value C as ~ full name ~');
+      node.addCE('there is a transform named t1 that has \'full name\' as output and has \'this.first_name + " " + this.last_name\' as transform function');
+      node.addCE('there is a person named p1 that has Jane as first name and has Smith as last name and uses the transform t1');
+      expect(node.instances.p1.full_name).to.be('Jane Smith');
+      node.addCE('the person p1 has Harry as first name');
+      expect(node.instances.p1.first_name).to.be('Harry');
+      expect(node.instances.p1.full_name).to.be('Harry Smith');
+
+      node.addCE('there is a transform named t2 that has date as output and has \'new Date(parseInt(this.name))\' as transform function');
+      node.addCE('there is a timestamp named \'715263762315\' that uses the transform t2');
+      expect(node.getInstanceByName('715263762315').date).to.contain('1992');
+    });
+
+    it('allow for transform chaining', () => {
+      const node = new CENode(CEModels.core);
+      node.addSentence("conceptualise a ~ person ~ P that is a transformer and has the value A as ~ first name ~ and has the value B as ~ last name ~ and has the value C as ~ full name ~ and has the value D as ~ username ~")
+
+      node.addSentence("there is a transform named t1 that has 'full name' as output and has 'this.first_name + \\'  \\' + this.last_name' as transform function")
+      node.addSentence("there is a transform named t2 that has 'username' as output and has 'this.full_name.toLowerCase().replace(/ /g, \\'_\\')' as transform function");
+
+      node.addSentence("there is a person named p1 that has 'Jane' as first name and has 'Smith' as last name and uses the transform t1 and uses the transform t2");
+
+      expect(node.instances.p1.full_name).to.be('Jane Smith');
+      expect(node.instances.p1.username).to.be('jane_smith');
+
+      node.addSentence('the person p1 has \'Harry\' as first name');
+      expect(node.instances.p1.full_name).to.be('Harry Smith');
+      expect(node.instances.p1.username).to.be('harry_smith');
+    });
   });
 
   describe('Specific Examples', function() {