Added sort from the request query param

composer.json

@@ -14,7 +14,8 @@
     "illuminate/pagination": ">=5.5",
     "illuminate/console": ">=5.5",
     "elasticsearch/elasticsearch": "^7",
-    "erichard/elasticsearch-query-builder": "dev-collapse-and-improvments#9551a1e51d4059121072130716a9a31357283a08"
+    "erichard/elasticsearch-query-builder": "dev-collapse-and-improvments#9551a1e51d4059121072130716a9a31357283a08",
+    "illuminate/validation": ">=5.5"
   },
   "require-dev": {
     "friendsofphp/php-cs-fixer": "^2.16",

readme.md

@@ -148,6 +148,38 @@ Property mappings types using constants like:
             by provided this option.
     ```
 
+**Sorting**
+
+To enable sortable behavior add `HasSorting` trait to your instance of `AbstractBuilder` and implement method `allowedSortFields`.
+
+```
+/**
+ * Allowed fields for sorting.
+ *
+ * Key is the name of the field in the query.
+ * Value is the name of the field in the index.
+ *
+ * @return array
+ */
+public function allowedSortFields(): array
+{
+    return [
+        'goals' => 'goals_count',
+        'minutes' => 'played_minutes',
+    ];
+}
+```
+
+With sorting enabled you can sort the results using `sort` request query parameter. This parameter accepts list of fields for sorting in format `{field_name}:{sort_direction}`.
+
+Available directions for sorting are `asc` and `desc` and if not specified the default sort direction is set to `asc`.
+
+**Examples:**
+
+`sort[]=goals`
+
+`sort[]=goals:asc&sort[]=minutes:desc`
+
 ## TODO
 
 - improve documentation

src/Constants/SortDirections.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Lelastico\Constants;
+
+final class SortDirections
+{
+    public const ASC = 'asc';
+    public const DESC = 'desc';
+
+    public static function getAll(): array
+    {
+        return [
+            self::ASC,
+            self::DESC,
+        ];
+    }
+}

src/Search/Query/AbstractBuilder.php

@@ -12,6 +12,7 @@
 use Lelastico\Indices\AbstractElasticIndex;
 use Lelastico\Search\Query\Traits\AddQueries;
 use Lelastico\Search\Query\Traits\HasPaginationSettings;
+use Lelastico\Search\Query\Traits\HasSorting;
 use Lelastico\Search\Query\Traits\LogQuery;
 use Lelastico\Search\Query\Traits\ParseResultsFromHits;
 use Psr\Log\LoggerInterface;
@@ -74,6 +75,11 @@ public function paginate(): LengthAwarePaginator
             $this->query->addFilter($this->filter);
         }
 
+        // Add sort if enabled
+        if (in_array(HasSorting::class, class_uses($this), true)) {
+            $this->addSort($this->query, $this->request);
+        }
+
         // Build the query and improve it
         $query = $this->query->getQuery();
 

src/Search/Query/Traits/HasSorting.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace Lelastico\Search\Query\Traits;
+
+use Erichard\ElasticQueryBuilder\QueryBuilder;
+use Illuminate\Http\Request;
+use Illuminate\Validation\Rule;
+use Lelastico\Constants\SortDirections;
+
+/**
+ * Adds sortable behavior to the query builder from the request "sort" query parameter.
+ */
+trait HasSorting
+{
+    /**
+     * Allowed fields for sorting.
+     *
+     * Key is the name of the field in the query.
+     * Value is the name of the field in the index.
+     *
+     * [
+     *     'goals' => 'goals_count'
+     *     'minutes' => 'played_minutes'
+     * ]
+     *
+     * @return array
+     */
+    abstract public function allowedSortFields(): array;
+
+    protected function addSort(QueryBuilder $query, Request $request): void
+    {
+        if ($request->missing('sort')) {
+            return;
+        }
+
+        $request->validate($this->getValidationRules());
+
+        foreach ($request->get('sort') as $sort) {
+            $exploded = explode(':', $sort);
+
+            $field = $this->allowedSortFields()[$exploded[0]];
+            $direction = $exploded[1] ?? SortDirections::ASC;
+
+            $query->addSort($field, $direction);
+        }
+    }
+
+    private function getSortFields(): array
+    {
+        $values = [];
+
+        foreach (array_keys($this->allowedSortFields()) as $field) {
+            $values[] = $field;
+            foreach (SortDirections::getAll() as $direction) {
+                $values[] = "{$field}:{$direction}";
+            }
+        }
+
+        return $values;
+    }
+
+    private function getValidationRules(): array
+    {
+        return [
+            'sort' => ['required', 'array'],
+            'sort.*' => ['required', 'string', Rule::in($this->getSortFields())],
+        ];
+    }
+}