apachesolr_rss.module

<?php
/**
 * @file 
 * 
 * Copyright 2012 New Signature
 * http://www.newsignature.com
 *
 * @author Andrew Marcus
 * @since Mar 9, 2012
 */

/**
 * Implements hook_permission().
 */
function apachesolr_rss_permission() {
  $permissions = array(
    'rss search results' => array(
      'title' => t('View RSS Search results'),
      'description' => t('Allows users to get search results as an RSS feed'),
    ),
  );
  return $permissions;
}

/**
 * Implements hook_menu().
 */
function apachesolr_rss_menu() {
  $items = array();
  
  try {
    // Gets search pages directly from the index.
    // @todo Honor "enabled" settings?
    $result = db_select('apachesolr_search_page', 's')
      ->fields('s', array('page_id', 'search_path', 'page_title', 'env_id'))
      ->condition('env_id', '', '<>')
      ->execute();
  }
  catch (Exception $e) {
    watchdog_exception('apachesolr_search', $e);
    $result = array();
  }

  // Gets default search information.
  $default_info = search_get_default_module_info();

  // Iterates over search pages, builds menu items.
  foreach ($result as $record) {
    // Validate the environemnt ID in case of import or missed deletion.
    $environment = apachesolr_environment_load($record->env_id);
    if (!$environment) {
      continue;
    }
    // Parses search path into it's various parts, builds menu items dependent
    // on whether %keys is in the path.
    $parts = explode('/', $record->search_path);
    $keys_pos = count($parts);
    // Tests whether we are simulating a core search tab.
    $core_search = ($parts[0] == 'search');

    $items[$record->search_path . '/rss'] = array(
      'title' => $record->page_title,
      'page callback' => 'apachesolr_rss_search_page',
      'page arguments' => array($record->page_id, ''),
      'access arguments' => array('rss search results'),
      'type' => ($core_search) ? MENU_LOCAL_TASK : MENU_SUGGESTED_ITEM,
    );

    $items[$record->search_path . '/rss/%menu_tail'] = array(
      'title' => $record->page_title,
      'load arguments' => array('%map', '%index'),
      'page callback' => 'apachesolr_rss_search_page',
      'page arguments' => array($record->page_id, $keys_pos + 1),
      'access arguments' => array('rss search results'),
      'type' => MENU_LOCAL_TASK,
    );
  }
  
  return $items;
}

function apachesolr_rss_search_page($page_id, $keys = '') {
  $search_page = apachesolr_search_page_load($page_id);

  $filters = isset($search_page->settings['fq']) ? $search_page->settings['fq'] : array();
  $solrsort = isset($_GET['solrsort']) ? $_GET['solrsort'] : '';
  
  $params = drupal_get_query_parameters();
  $params['q'] = $keys;
  $params['fq'] = $filters;

  try {
    $solr = apachesolr_get_solr($search_page->env_id);
    $nids = array();

    $results = apachesolr_search_run('apachesolr', $params, $solrsort, $search_page->search_path, pager_find_page(), $solr);
      
    foreach ($results as $result) {
      if ($result['entity_type'] == 'node' && isset($result['fields']['entity_id'])) {
        $nids[] = $result['fields']['entity_id'];
      }
    }
    $channel = array(
      'title' => t('@site | Search Results', array(
        '@site' => variable_get('site_name', 'Drupal')
      )),
      'link' => url($_GET['q'], array(
        'query' => drupal_get_query_parameters(),
        'absolute' => TRUE,
      )),
    );
    $context = array(
      'keys' => $keys, 
      'params' => $params,
      'page' => $search_page,
    );
    drupal_alter('apachesolr_rss_channel', $channel, $context);
    
    node_feed($nids, $channel);
  }
  catch (Exception $e) {
    watchdog('Apache Solr', nl2br(check_plain($e->getMessage())), NULL, WATCHDOG_ERROR);
    apachesolr_failure(t('Solr search'), $keys);
    return '';
  }
}

function apachesolr_rss_feed_url($url = NULL, $params = NULL) {
  $paths = &drupal_static(__FUNCTION__, array());
  
  // Current page URL
  if (!isset($url)) {
    $url = $_GET['q'];
  }
  if (!isset($paths[$url])) {
    $item = menu_get_item($url);
    $path = array();
    if ($item) {
      foreach ($item['map'] as $key => $val) {
        // If there is a load function for the rest of the menu path, insert the 'rss' item before it
        if (isset($item['load_functions'][$key]) && $item['load_functions'][$key] == 'menu_tail_load') {
          $path[] = 'rss';
        }
        $path[] = $val;
      }
      if (!in_array('rss', $path)) {
        $path[] = 'rss';
      }
    }
    else {
      $path = array($url, 'rss');
    }
    $paths[$url] = implode('/', $path);
  }
  if (!isset($params)) {
    $params = drupal_get_query_parameters($_GET, array('q', 'rows', 'page'));
  }
  
  return array( $paths[$url], array(
    'query' => $params,
  ));
}

/**
 * Implements hook_preprocess_search_results().
 */
function apachesolr_rss_preprocess_search_results(&$variables) {
  list($path, $options) = apachesolr_rss_feed_url();
  
  drupal_add_html_head_link(array(
    'rel' => 'alternate',
    'type' => 'application/rss+xml',
    'title' => t('RSS'),
    'href' => url($path, $options + array( 'absolute' => TRUE )),
  ));
}