added template query

src/Query/TemplateQuery.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\Query;
+
+use ONGR\ElasticsearchDSL\BuilderInterface;
+use ONGR\ElasticsearchDSL\ParametersTrait;
+
+/**
+ * Represents Elasticsearch "template" query.
+ *
+ * @link https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-template-query.html
+ */
+class TemplateQuery implements BuilderInterface
+{
+    use ParametersTrait;
+
+    /**
+     * @var string
+     */
+    private $file;
+
+    /**
+     * @var string
+     */
+    private $inline;
+
+    /**
+     * @var array
+     */
+    private $params;
+
+    /**
+     * @param string $file A template of the query
+     * @param string $inline A template of the query
+     * @param array  $params Parameters to insert into template
+     */
+    public function __construct($file = null, $inline = null, array $params = [])
+    {
+        $this->setFile($file);
+        $this->setInline($inline);
+        $this->setParams($params);
+    }
+
+    /**
+     * @return string
+     */
+    public function getFile()
+    {
+        return $this->file;
+    }
+
+    /**
+     * @param string $file
+     */
+    public function setFile($file)
+    {
+        $this->file = $file;
+    }
+
+    /**
+     * @return string
+     */
+    public function getInline()
+    {
+        return $this->inline;
+    }
+
+    /**
+     * @param string $inline
+     */
+    public function setInline($inline)
+    {
+        $this->inline = $inline;
+    }
+
+    /**
+     * @return array
+     */
+    public function getParams()
+    {
+        return $this->params;
+    }
+
+    /**
+     * @param array $params
+     */
+    public function setParams($params)
+    {
+        $this->params = $params;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getType()
+    {
+        return 'template';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toArray()
+    {
+        $output = array_filter(
+            [
+                'file' => $this->getFile(),
+                'inline' => $this->getInline(),
+                'params' => $this->getParams(),
+            ]
+        );
+
+        if (!isset($output['file']) && !isset($output['inline'])) {
+            throw new \InvalidArgumentException(
+                'Template query requires that either `inline` or `file` parameters are set'
+            );
+        }
+
+        $output = $this->processArray($output);
+
+        return [$this->getType() => $output];
+    }
+}