Merge pull request #133 from einorler/pipeline_percentile_bucket

Added percentile pipeline aggregation

docs/Aggregation/Pipeline/PercentilesBucket.md

+# Percentiles Bucket Aggregation
+
+> More info about avg bucket aggregation is in the [official elasticsearch docs][1]
+
+A sibling pipeline aggregation which calculates percentiles across all bucket of a 
+specified metric in a sibling aggregation. The specified metric must be numeric and 
+the sibling aggregation must be a multi-bucket aggregation.
+
+## Simple example
+
+```JSON
+{
+    "aggs" : {
+        "sales_per_month" : {
+            "date_histogram" : {
+                "field" : "date",
+                "interval" : "month"
+            },
+            "aggs": {
+                "sales": {
+                    "sum": {
+                        "field": "price"
+                    }
+                }
+            }
+        },
+        "sum_monthly_sales": {
+            "percentiles_bucket": {
+                "buckets_path": "sales_per_month>sales", 
+                "percents": [ 25.0, 50.0, 75.0 ] 
+            }
+        }
+    }
+}
+```
+
+And now the query via DSL:
+
+```php
+$search = new Search();
+
+$dateAggregation = new DateHistogramAggregation('sales_per_month', 'date', 'month');
+$dateAggregation->addAggregation(
+    new SumAggregation('sales', 'price')
+);
+$percentilesAggregation = new AvgBucketAggregation('sum_monthly_sales', 'sales_per_month>sales')
+$percentilesAggregation->setPercentiles([25.0, 50.0, 75.0]);
+
+$search->addAggregation($dateAggregation);
+$search->addAggregation($percentilesAggregation);
+
+$aggArray = $search->toArray();
+```
+
+[1]: https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-pipeline-percentiles-bucket-aggregation.html
\ No newline at end of file

src/Aggregation/Pipeline/PercentilesBucketAggregation.php

+<?php
+
+/*
+ * This file is part of the ONGR package.
+ *
+ * (c) NFQ Technologies UAB <info@nfq.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ONGR\ElasticsearchDSL\Aggregation\Pipeline;
+
+/**
+ * Class representing Percentiles Bucket Pipeline Aggregation.
+ *
+ * @link https://goo.gl/bqi7m5
+ */
+class PercentilesBucketAggregation extends AbstractPipelineAggregation
+{
+    /**
+     * @var array
+     */
+    private $percents;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getType()
+    {
+        return 'percentiles_bucket';
+    }
+
+    /**
+     * @return array
+     */
+    public function getPercents()
+    {
+        return $this->percents;
+    }
+
+    /**
+     * @param array $percents
+     */
+    public function setPercents(array $percents)
+    {
+        $this->percents = $percents;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getArray()
+    {
+        $data = ['buckets_path' => $this->getBucketsPath()];
+
+        if ($this->getPercents()) {
+            $data['percents'] = $this->getPercents();
+        }
+
+        return $data;
+    }
+}

tests/Aggregation/Pipeline/PercentilesBucketAggregationTest.php

+<?php
+
+/*
+ * This file is part of the ONGR package.
+ *
+ * (c) NFQ Technologies UAB <info@nfq.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ONGR\ElasticsearchDSL\Tests\Aggregation\Pipeline;
+
+use ONGR\ElasticsearchDSL\Aggregation\Pipeline\PercentilesBucketAggregation;
+
+/**
+ * Unit test for percentiles bucket aggregation.
+ */
+class PercentilesBucketAggregationTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * Tests toArray method.
+     */
+    public function testToArray()
+    {
+        $aggregation = new PercentilesBucketAggregation('acme', 'test');
+        $aggregation->setPercents([25.0, 50.0, 75.0]);
+
+        $expected = [
+            'percentiles_bucket' => [
+                'buckets_path' => 'test',
+                'percents' => [25.0, 50.0, 75.0],
+            ],
+        ];
+
+        $this->assertEquals($expected, $aggregation->toArray());
+    }
+}