Feature: support for scripted metric aggrations

lib/Elastica/Aggregation/ScriptedMetric.php

@@ -0,0 +1,85 @@
+<?php
+
+namespace Elastica\Aggregation;
+
+/**
+ * Class ScriptedMetric
+ * @package Elastica\Aggregation
+ * @link    http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations-metrics-scripted-metric-aggregation.html
+ */
+class ScriptedMetric extends AbstractAggregation
+{
+
+    /**
+     * @param string      $name          the name if this aggregation
+     * @param string|null $initScript    Executed prior to any collection of documents
+     * @param string|null $mapScript     Executed once per document collected
+     * @param string|null $combineScript Executed once on each shard after document collection is complete
+     * @param string|null $reduceScript  Executed once on the coordinating node after all shards have returned their results
+     */
+    public function __construct($name, $initScript = null, $mapScript = null, $combineScript = null, $reduceScript = null)
+    {
+        parent::__construct($name);
+        if ($initScript) {
+            $this->setInitScript($initScript);
+        }
+        if ($mapScript) {
+            $this->setMapScript($mapScript);
+        }
+        if ($combineScript) {
+            $this->setCombineScript($combineScript);
+        }
+        if ($reduceScript) {
+            $this->setReduceScript($reduceScript);
+        }
+    }
+
+    /**
+     * Set the field for this aggregation
+     *
+     * @param  string $script the name of the document field on which to perform this aggregation
+     *
+     * @return static
+     */
+    public function setCombineScript($script)
+    {
+        return $this->setParam('combine_script', $script);
+    }
+
+    /**
+     * Set the field for this aggregation
+     *
+     * @param  string $script the name of the document field on which to perform this aggregation
+     *
+     * @return static
+     */
+    public function setInitScript($script)
+    {
+        return $this->setParam('init_script', $script);
+    }
+
+    /**
+     * Set the field for this aggregation
+     *
+     * @param  string $script the name of the document field on which to perform this aggregation
+     *
+     * @return static
+     */
+    public function setMapScript($script)
+    {
+        return $this->setParam('map_script', $script);
+    }
+
+    /**
+     * Set the field for this aggregation
+     *
+     * @param  string $script the name of the document field on which to perform this aggregation
+     *
+     * @return static
+     */
+    public function setReduceScript($script)
+    {
+        return $this->setParam('reduce_script', $script);
+    }
+
+}

lib/Elastica/QueryBuilder/DSL/Aggregation.php

@@ -20,6 +20,7 @@
 use Elastica\Aggregation\Nested;
 use Elastica\Aggregation\Range;
 use Elastica\Aggregation\ReverseNested;
+use Elastica\Aggregation\ScriptedMetric;
 use Elastica\Aggregation\Stats;
 use Elastica\Aggregation\Sum;
 use Elastica\Aggregation\Terms;
@@ -194,11 +195,18 @@ public function top_hits($name)
      * scripted metric aggregation
      *
      * @link http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations-metrics-scripted-metric-aggregation.html
-     * @param string $name
+     *
+     * @param string      $name
+     * @param string|null $initScript
+     * @param string|null $mapScript
+     * @param string|null $combineScript
+     * @param string|null $reduceScript
+     *
+     * @return ScriptedMetric
      */
-    public function scripted_metric($name)
+    public function scripted_metric($name, $initScript = null, $mapScript = null, $combineScript = null, $reduceScript = null)
     {
-        throw new NotImplementedException();
+        return new ScriptedMetric($name, $initScript, $mapScript, $combineScript, $reduceScript);
     }
 
     /**

test/lib/Elastica/Test/Aggregation/ScriptedMetricTest.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace Elastica\Test\Aggregation;
+
+use Elastica\Aggregation\ScriptedMetric;
+use Elastica\Document;
+use Elastica\Query;
+use Elastica\Type\Mapping;
+
+class ScriptedMetricTest extends BaseAggregationTest
+{
+    protected function setUp()
+    {
+        parent::setUp();
+        $this->_index = $this->_createIndex();
+        $mapping = new Mapping();
+        $mapping->setProperties(array(
+            "start" => array("type" => "long"),
+            "end"   => array("type" => "long"),
+        ));
+        $type = $this->_index->getType("test");
+        $type->setMapping($mapping);
+        $docs = array(
+            new Document("1", array("start" => 100, "end" => 200)),
+            new Document("2", array("start" => 200, "end" => 250)),
+            new Document("3", array("start" => 300, "end" => 450)),
+        );
+        $type->addDocuments($docs);
+        $this->_index->refresh();
+    }
+
+    public function testScriptedMetricAggregation()
+    {
+        $agg = new ScriptedMetric(
+            "scripted",
+            "_agg['durations'] = [:]",
+            "key = doc['start'].value+ \":\"+ doc['end'].value; _agg.durations[key] = doc['end'].value - doc['start'].value;",
+            "values = []; for (item in _agg.durations) { values.add(item.value) }; return values"
+        );
+
+        $query = new Query();
+        $query->addAggregation($agg);
+        $results = $this->_index->search($query)->getAggregation("scripted");
+
+        $this->assertEquals(array(100, 50, 150), $results['value'][0]);
+    }
+}