feat (audience match types): Condition evaluator and Project Config PRs consolidation. (#150)

Author: oakbani

src/Optimizely/ProjectConfig.php

@@ -214,13 +214,15 @@ public function __construct($datafile, $logger, $errorHandler)
         $events = $config['events'] ?: [];
         $attributes = $config['attributes'] ?: [];
         $audiences = $config['audiences'] ?: [];
+        $typedAudiences = isset($config['typedAudiences']) ? $config['typedAudiences']: [];
         $rollouts = isset($config['rollouts']) ? $config['rollouts'] : [];
         $featureFlags = isset($config['featureFlags']) ? $config['featureFlags']: [];
 
         $this->_groupIdMap = ConfigParser::generateMap($groups, 'id', Group::class);
         $this->_experimentKeyMap = ConfigParser::generateMap($experiments, 'key', Experiment::class);
         $this->_eventKeyMap = ConfigParser::generateMap($events, 'key', Event::class);
         $this->_attributeKeyMap = ConfigParser::generateMap($attributes, 'key', Attribute::class);
+        $typedAudienceIdMap = ConfigParser::generateMap($typedAudiences, 'id', Audience::class);
         $this->_audienceIdMap = ConfigParser::generateMap($audiences, 'id', Audience::class);
         $this->_rollouts = ConfigParser::generateMap($rollouts, null, Rollout::class);
         $this->_featureFlags = ConfigParser::generateMap($featureFlags, null, FeatureFlag::class);
@@ -249,12 +251,19 @@ public function __construct($datafile, $logger, $errorHandler)
             }
         }
 
-        $conditionDecoder = new ConditionDecoder();
         foreach (array_values($this->_audienceIdMap) as $audience) {
-            $conditionDecoder->deserializeAudienceConditions($audience->getConditions());
-            $audience->setConditionsList($conditionDecoder->getConditionsList());
+            $audience->setConditionsList(json_decode($audience->getConditions(), true));
         }
 
+        // Conditions in typedAudiences are not expected to be string-encoded so they don't need
+        // to be decoded unlike audiences. 
+        foreach (array_values($typedAudienceIdMap) as $typedAudience) {
+            $typedAudience->setConditionsList($typedAudience->getConditions());
+        }
+
+        // Overwrite audiences by typedAudiences.
+        $this->_audienceIdMap = array_replace($this->_audienceIdMap, $typedAudienceIdMap);
+
         $rolloutVariationIdMap = [];
         $rolloutVariationKeyMap = [];
         foreach ($this->_rollouts as $rollout) {

src/Optimizely/Utils/ConditionDecoder.php

@@ -0,0 +1,158 @@
+<?php
+/**
+ * Copyright 2018, Optimizely
+ *
+ * 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.
+ */
+
+namespace Optimizely\Utils;
+
+class ConditionTreeEvaluator
+{
+    const AND_OPERATOR = 'and';
+    const OR_OPERATOR = 'or';
+    const NOT_OPERATOR = 'not';
+
+    /**
+     * Returns an array of supported operators.
+     * 
+     * @return array List of operators.
+     */
+    protected function getOperators()
+    {
+        return array(self::AND_OPERATOR, self::OR_OPERATOR, self::NOT_OPERATOR);
+    }
+
+    /**
+     * Returns corresponding evaluator method name for the given operator.
+     * 
+     * @param  mixed  $operator  Operator to get relevant evaluator method. 
+     * 
+     * @return string Corresponding method to the given operator.
+     */
+    protected function getEvaluatorByOperatorType($operator)
+    {
+        $evaluatorsByOperator = array();
+        $evaluatorsByOperator[self::AND_OPERATOR] = 'andEvaluator';
+        $evaluatorsByOperator[self::OR_OPERATOR] = 'orEvaluator';
+        $evaluatorsByOperator[self::NOT_OPERATOR] = 'notEvaluator';
+
+        return $evaluatorsByOperator[$operator];
+    }
+
+    /**
+     * Evaluates an array of conditions as if the evaluator had been applied
+     * to each entry and the results AND-ed together.
+     * 
+     * @param array     $conditions  Audience conditions list.
+     * @param callable  $leafEvaluator Method to evaluate leaf condition. 
+     *
+     * @return null|boolean True if all the operands evaluate to true.
+     *                      False if a single operand evaluates to false.
+     *                      Null if conditions couldn't be evaluated.
+     */
+    protected function andEvaluator(array $conditions, callable $leafEvaluator)
+    {
+        $sawNullResult = false;
+        foreach ($conditions as $condition) {
+            $result = $this->evaluate($condition, $leafEvaluator);
+            
+            if($result === false) {
+                return false;
+            }
+
+            if($result === null) {
+                $sawNullResult = true;
+            }
+        }
+
+        return $sawNullResult ? null : true;
+    }
+
+    /**
+     * Evaluates an array of conditions as if the evaluator had been applied
+     * to each entry and the results OR-ed together.
+     * 
+     * @param array     $conditions  Audience conditions list.
+     * @param callable  $leafEvaluator Method to evaluate leaf condition. 
+     *
+     * @return null|boolean True if any operand evaluates to true.
+     *                    False if all operands evaluate to false.
+     *                    Null if conditions couldn't be evaluated.
+     */
+    protected function orEvaluator(array $conditions, callable $leafEvaluator)
+    {
+        $sawNullResult = false;
+        foreach ($conditions as $condition) {
+            $result = $this->evaluate($condition, $leafEvaluator);
+
+            if($result === true) {
+                return true;
+            }
+
+            if($result === null) {
+                $sawNullResult = true;
+            }
+        }
+
+        return $sawNullResult ? null : false;
+    }
+
+    /**
+     * Evaluates an array of conditions as if the evaluator had been applied
+     * to a single entry and NOT was applied to the result.
+     * 
+     * @param array     $conditions  Audience conditions list.
+     * @param callable  $leafEvaluator Method to evaluate leaf condition. 
+     *
+     * @return null|boolean True if the operand evaluates to false.
+     *                      False if the operand evaluates to true.
+     *                      Null if conditions is empty or couldn't be evaluated.
+     */
+    protected function notEvaluator(array $condition, callable $leafEvaluator)
+    {
+        if (empty($condition)) {
+            return null;
+        }
+
+        $result = $this->evaluate($condition[0], $leafEvaluator);
+        return $result === null ? null: !$result;
+    }
+
+    /**
+     * Function to evaluate audience conditions against user's attributes.
+     *
+     * @param array     $conditions Nested array of and/or/not conditions representing the audience conditions.
+     * @param callable  $leafEvaluator Method to evaluate leaf condition. 
+     *
+     * @return null|boolean Result of evaluating the conditions using the operator rules.
+     *                      and the leaf evaluator. Null if conditions couldn't be evaluated.
+     */
+    public function evaluate($conditions, callable $leafEvaluator)
+    {
+        if (!Validator::doesArrayContainOnlyStringKeys($conditions)) {
+
+            if(in_array($conditions[0], $this->getOperators())) {
+                $operator = array_shift($conditions);
+            } else {
+                $operator = self::OR_OPERATOR;
+            }
+
+            $evaluatorFunc = $this->getEvaluatorByOperatorType($operator);
+            return $this->{$evaluatorFunc}($conditions, $leafEvaluator);
+        }
+
+        $leafCondition = $conditions;
+        return $leafEvaluator($leafCondition);
+    }
+}