Merge pull request #232 from hkulekci/documentation-update-for-search-callback

readme changed to mention about callback function parameters of the search

Author: matchish

README.md

@@ -195,13 +195,13 @@ There is two ways.
 By default, when you pass a query to the `search` method, the engine builds a [query_string](https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html) query, so you can build queries like this
 
 ```php
-Product::search('title:this OR description:this) AND (title:that OR description:that')`
+Product::search('(title:this OR description:this) AND (title:that OR description:that)')
 ```
 
 If it's not enough in your case you can pass a callback to the query builder
 
 ```php
-$results = Product::search('zonga', function($client, $body) {
+$results = Product::search('zonga', function(\Elastic\Elasticsearch\Client $client, $body) {
 
     $minPriceAggregation = new MinAggregation('min_price');
     $minPriceAggregation->setField('price');
@@ -219,8 +219,14 @@ $results = Product::search('zonga', function($client, $body) {
 })->raw();
 ```
 
-`$client` is `\ElasticSearch\Client` object from [elasticsearch/elasticsearch](https://packagist.org/packages/elasticsearch/elasticsearch) package  
- And `$body` is `ONGR\ElasticsearchDSL\Search` from [ongr/elasticsearch-dsl](https://packagist.org/packages/ongr/elasticsearch-dsl) package  
+> Note : The callback function will get 2 parameters. First one is `$client` and it is an object of `\Elastic\Elasticsearch\Client` 
+> class from [elasticsearch/elasticsearch](https://packagist.org/packages/elasticsearch/elasticsearch) package. 
+> And the second one is `$body` which is an object of `\ONGR\ElasticsearchDSL\Search` from 
+> [ongr/elasticsearch-dsl](https://packagist.org/packages/handcraftedinthealps/elasticsearch-dsl) package. So, while
+> as you can see the example above, `$client->search(....)` method will return an 
+> `\Elastic\Elasticsearch\Response\Elasticsearch` object. And you need to use `asArray()` method to get array result. 
+> Otherwise, the `HitsIteratorAggregate` class will throw an error. You can check the issue 
+> [here](https://github.com/matchish/laravel-scout-elasticsearch/issues/215).
 
 ### Search amongst multiple models
 You can do it with `MixedSearch` class, just pass indices names separated by commas to the `within` method.