Drupal 6: Getting Apache Solr to show all results and facets without searching

I’ve encountered this issue a few times recently when working with Apache Solr (in Drupal 6): clients want to to show all search results and allow the users to browse facets, instead of requiring a search phrase or filter to begin the search. The current version of the Apache Solr module appears to require at least one of these items.

Querying Solr directly allows you to return all search results using the query/select URL. Example: http://example.com:8080/solr/select
Entering a keyword works. Example: http://example.com/search/apachesolr_search/blah
Entering a keyword AND taxonomy filter works. Example: http://example.com/search/apachesolr_search/blah?filters=tid%3A22
Entering a taxonomy filter WITHOUT a keyword works. Example: http://example.com/search/apachesolr_search/?filters=tid%3A22
No keyword AND no filter returns nothing (dang). Example: http://example.com/search/apachesolr_search

A quick look at apachesolr_search.module, in the function: apachesolr_search_view() shows this is not going to happen:

<?php
$keys = trim(search_get_keys());
// ...snip...
$filters = trim($_GET['filters']);
// ...snip...
if ($keys || $filters) {
  // do search
}
?>

So what if there was a way to modify the $_GET values prior to the apache solr search page callback? hook_boot maybe? NOTE: hook_boot functions are only processed if the bootstrap column in the system table for your module is set to 1! Example SQL to update..

update {system}
set bootstrap = 1
where type = 'module' and name = 'MYMODULE'

I then created this hook_boot function in my module. It is run prior to the the apache solr search page callback, and allows me to tamper with $_GET variables. In this case, I just add a fake filter to allow the search to pass the above conditional statements.

<?php
function MYMODULE_boot() {

  // check for search page
  $search_path = 'search/apachesolr_search';
  if (substr($_GET['q'], 0, strlen($search_path))==$search_path) {

    // get search phrase
    $search_phrase = substr($_GET['q'], strlen($search_path)+1);

    // get filters
    $filters = $_GET['filters'];

    // check if filters AND search phrase do not exist
    if (empty($filters) && empty($search_phrase)) {

      // set fake filter
      $_GET['filters'] = 1;

    }
  }

}
?>

Now going to the solr search page defaults to show all results and facets:

Solr All Results

It appears to work, but anyone know of a better way to accomplish this?! :)

Eric London