10up/ElasticPress — pull request #177 by tlovett1 (2014-12-22 22:27:36+00:00)
Title: Support meta_query argument in query integration

This PR adds support for `meta_query`. It supports queries like so:

```php
new WP_Query( array(
's' => 'search phrase',
'meta_query' => array(
array(
'key' => 'key_name',
'value' => 'meta value',
'compare' => '=',
),
array(
'key' => 'key_name2',
'value' => 'meta value',
'compare' => '!=',
),
'relation' => 'AND',
),
) );
```

With this PR `compare` supports `!=`, `=`, `EXISTS`, and `NOT EXISTS`. `relation` supports `OR` and `AND.