Please add my vote for this request. It looks like the new search in Piwigo 14 has not yet opened this option.

In our case it is about ships with 5 digit registration numbers. We're currently adding them as tags, but this has 2 major drawbacks:

1. The number of tags grows enormously
2. 5-digit numbers can also be part of a date, filename etc. This is confusing to the volunteers working on tagging the collection. So we had to ad extra characters to them to make them unique.

IMHO this will enhance Piwigo's usability as an image library for organisations.

@BobbyV I'm not involved with that ships photobase project anymore, but I think in many other situations custom fields will only be useful if they can be searched.

I'm not a developer (and my brain is not much younger) but I work with WordPress a lot. Like Piwigo, WordPress is a PHP/MySQL application. In WordPress custom fields can be added to all post types and taxonomies, but the default WordPress search only looks at title and post content. However there are several plugins that extend the search functionality and it also seems to be possible by adding a few lines of code in a code-snippet plugin or child-theme. See the 2nd answer in this topic for example.

So it looks like in WordPress the solution is to (slightly) extend the search function rather than adding tables.

I have been able lookup images using data in a Manage Properties Photos added property (non-date) using the Piwigo search page through a bit of Personal Plugin code. Unfortunately, the method I used is not intuitive from a user perspective as it uses the expert mode filter instead of the "search for words" input.

I also added a FULLTEXT index to the ADD_PROP_PHOTO_DATA_TABLE 'data' column as I was reusing some existing code in include/functions_search.inc.php but there is probably a different way to generate the query so as not to require changing the database schema of another plugin's table.

I think there might also be another approach that would work as there are some other triggers available in include/functions_search.inc.php that I don't currently understand how to use.

add_event_handler('qsearch_get_scopes', 'personal_extend_search_scopes');
function personal_extend_search_scopes($scopes)
{
  $scopes[] = new QSearchScope('add_info', array('add_info'));
  return $scopes;
}

add_event_handler('qsearch_before_eval', 'personal_qsearch_get_image_by_add_info_text');
function personal_qsearch_get_image_by_add_info_text(QExpression $expr, QResults $qsr)
{
  for ($i=0; $i<count($expr->stokens); $i++)
  {
    $token = $expr->stokens[$i];
    if (isset($token->scope) && 'add_info' != $token->scope->id)
      continue;
    if (empty($token->term))
      continue;

    $clauses = qsearch_get_text_token_search_sql( $token, array('data'));
    $query = 'SELECT id_img FROM '.ADD_PROP_PHOTO_DATA_TABLE.' WHERE ('. implode("\n OR ",$clauses) .');';
    $result = query2array($query, null, 'id_img');  
    $query = 'SELECT id from '.IMAGES_TABLE.' i WHERE id IN ('. implode(",",$result) .');';
    $qsr->images_iids[$i] = query2array($query,null,'id');
  }
}

The triggers I am referring to are points (using the functions trigger_notify and trigger_change) in the Piwigo code that allow some other code to do something at that point by registering an event handler, for example a plugin or the LocalFiles Editor Personal Plugin (like what I posted).

Mostly the built-in search is applying queries against columns in the core images table but it can also search tags and albums. However a custom property added by the Manage Properties Photos plugin is stored in its own separate table with a reference to the image ID from the core images table.

The available core triggers are listed at /tools/triggers_list.php on a Piwigo instance (for example https://demo1.piwigo.com/tools/triggers_list.php) but there do seem to be some in /include/functions_search.inc.php that are not on that page. Maybe that means they are not supposed to be used in plugins but the code comments don't seem to indicate that so I'm not sure. I was able to make them work on my Piwigo 16 instance in any case.

I read through the core Piwigo include/functions_search.inc.php file looking for trigger_notify and trigger_change function calls that appeared to be intended to allow plugins to insert into the search process. Then I tried to figure out how to use them to insert image IDs returned from searching in the piwigo_add_properties_photos_data table into the results.

I have a use case where I would like to store a catalog reference from another system along with images in a Piwigo gallery and be able to lookup images using that information so that is why I am looking at how to connect the search tools with the Manage Properties Photos plugin.