Drupal 7: Snippet codes get related articles with Solr MLT

Drupal 7: Snippet codes get related articles with Solr

#
# Requirments: Drupal 7, Apache Solr
#
```
 <?php
 if (module_exists('apachesolr_search')) {
    $docs = array();
    $output = '';
    $env_id = apachesolr_default_environment(); // machine name of solr server
    $delta = 'mlt-001'; // "More Like This" block delta
    $block = apachesolr_search_mlt_block_load($delta);
    $solr = apachesolr_get_solr($env_id);
    $context['search_type'] = 'apachesolr_search_mlt';
    $context['block_id'] = $delta;
    $docs = apachesolr_search_mlt_suggestions($block, apachesolr_document_id($node->nid), $solr, $context);
    $view_mode = 'teaser';
    foreach ($docs as $doc) {
      if ($doc->entity_type == 'node') {
        $similar_node = node_load($doc->entity_id);
	$output .= '<li><a href="/node/'.$similar_node->nid.'">'.$similar_node->title."</a></li>";
      }
    }
    return '<ul style="list-style-type:none" class="mlt">'.$output."</ul>";
  }
 ?>
```