function file_tools_init()
{
    // extend CSS
    elgg_extend_view("css/elgg", "file_tools/css/site");
    if (file_tools_use_folder_structure()) {
        elgg_extend_view("groups/edit", "file_tools/group_settings");
    }
    // extend js
    elgg_extend_view("js/elgg", "file_tools/js/site");
    // register JS libraries
    $vendors = elgg_get_site_url() . "mod/file_tools/vendors/";
    elgg_register_js("jquery.tree", $vendors . "jstree/jquery.tree.min.js");
    elgg_register_css("jquery.tree", $vendors . "jstree/themes/default/style.css");
    elgg_register_js("jquery.hashchange", $vendors . "hashchange/jquery.hashchange.js");
    // register page handler for nice URL's
    elgg_register_page_handler("file_tools", "file_tools_page_handler");
    // make our own URLs for folders
    elgg_register_entity_url_handler("object", "file", "file_tools_url_handler");
    elgg_register_entity_url_handler("object", FILE_TOOLS_SUBTYPE, "file_tools_folder_url_handler");
    // make our own URLs for folder icons
    elgg_register_plugin_hook_handler("entity:icon:url", "object", "file_tools_folder_icon_hook");
    // register group option to allow management of file tree structure
    add_group_tool_option("file_tools_structure_management", elgg_echo("file_tools:group_tool_option:structure_management"));
    // register group option to allow group members to overwrite all their files
    add_group_tool_option("file_tools_file_management", elgg_echo("file_tools:group_tool_option:file_management"), false);
    // register widgets
    // add folder widget
    // need to keep file_tree for the widget name to be compatible with previous filetree plugin users
    elgg_register_widget_type("file_tree", elgg_echo("widgets:file_tree:title"), elgg_echo("widgets:file_tree:description"), "dashboard,profile,groups", true);
    // group files
    elgg_register_widget_type("group_files", elgg_echo("file:group"), elgg_echo("widgets:group_files:description"), "groups");
    // index files
    elgg_register_widget_type("index_file", elgg_echo("file"), elgg_echo("widgets:index_file:description"), "index", true);
    // register events
    elgg_register_event_handler("create", "object", "file_tools_object_handler");
    elgg_register_event_handler("update", "object", "file_tools_object_handler");
    elgg_register_event_handler("delete", "object", "file_tools_object_handler_delete");
    elgg_register_event_handler("upgrade", "system", "file_tools_upgrade_handler");
    // register hooks
    elgg_register_plugin_hook_handler("register", "menu:entity", "file_tools_entity_menu_hook");
    elgg_register_plugin_hook_handler("permissions_check", "object", "file_tools_can_edit_metadata_hook");
    elgg_register_plugin_hook_handler("route", "file", "file_tools_file_route_hook");
    elgg_register_plugin_hook_handler("widget_url", "widget_manager", "file_tools_widget_url_hook");
    elgg_register_plugin_hook_handler("register", "menu:file_tools_folder_breadcrumb", "file_tools_folder_breadcrumb_hook");
    elgg_register_plugin_hook_handler("register", "menu:file_tools_folder_sidebar_tree", "file_tools_folder_sidebar_tree_hook");
    // register actions
    elgg_register_action("file_tools/folder/edit", dirname(__FILE__) . "/actions/folder/edit.php");
    elgg_register_action("file_tools/folder/delete", dirname(__FILE__) . "/actions/folder/delete.php");
    elgg_register_action("file_tools/folder/reorder", dirname(__FILE__) . "/actions/folder/reorder.php");
    elgg_register_action("file_tools/folder/delete", dirname(__FILE__) . "/actions/folder/delete.php");
    elgg_register_action("file_tools/file/hide", dirname(__FILE__) . "/actions/file/hide.php");
    elgg_register_action("file_tools/file/upload", dirname(__FILE__) . "/actions/file/upload.php");
    elgg_register_action("file_tools/file/delete", dirname(__FILE__) . "/actions/file/delete.php");
    elgg_register_action("file/move", dirname(__FILE__) . "/actions/file/move.php");
    elgg_register_action("file/bulk_delete", dirname(__FILE__) . "/actions/file/bulk_delete.php");
    elgg_register_action("file_tools/groups/save_sort", dirname(__FILE__) . "/actions/groups/save_sort.php");
}

 /**
  * Add the folder management option to groups (if enabled)
  *
  * @param string $hook         the name of the hook
  * @param string $type         the type of the hook
  * @param array  $return_value current return value
  * @param arary  $params       supplied params
  *
  * @return void|array
  */
 public static function tools($hook, $type, $return_value, $params)
 {
     if (!file_tools_use_folder_structure()) {
         return;
     }
     $folder_management = new \stdClass();
     $folder_management->name = 'file_tools_structure_management';
     $folder_management->label = elgg_echo('file_tools:group_tool_option:structure_management');
     $folder_management->default_on = true;
     $return_value[] = $folder_management;
     return $return_value;
 }

function file_tools_file_route_hook($hook, $type, $returnvalue, $params)
{
    $result = $returnvalue;
    if (!empty($returnvalue) && is_array($returnvalue)) {
        $page = elgg_extract("segments", $returnvalue);
        switch ($page[0]) {
            case "view":
                if (!elgg_is_logged_in() && isset($page[1])) {
                    if (!get_entity($page[1])) {
                        gatekeeper();
                    }
                }
                break;
            case "owner":
                if (file_tools_use_folder_structure()) {
                    $result = false;
                    include dirname(dirname(__FILE__)) . "/pages/list.php";
                }
                break;
            case "group":
                if (file_tools_use_folder_structure()) {
                    $result = false;
                    include dirname(dirname(__FILE__)) . "/pages/list.php";
                }
                break;
            case "add":
                $result = false;
                include dirname(dirname(__FILE__)) . "/pages/file/new.php";
                break;
            case "zip":
                if (isset($page[1])) {
                    $result = false;
                    elgg_set_page_owner_guid($page[1]);
                    register_error(elgg_echo("changebookmark"));
                    forward("file/add/" . $page[1] . "?upload_type=zip");
                }
                break;
            case "bulk_download":
                $result = false;
                include dirname(dirname(__FILE__)) . "/pages/file/download.php";
                break;
        }
    }
    return $result;
}

 /**
  * Listen to the /file pagehandler
  *
  * @param string $hook         the name of the hook
  * @param string $type         the type of the hook
  * @param array  $return_value current return value
  * @param array  $params       supplied params
  *
  * @return void|false
  */
 public static function file($hook, $type, $return_value, $params)
 {
     $page = elgg_extract('segments', $return_value, []);
     switch (elgg_extract(0, $page)) {
         case 'owner':
             if (file_tools_use_folder_structure()) {
                 echo elgg_view_resource('file_tools/file/list');
                 return false;
             }
             break;
         case 'group':
             if (file_tools_use_folder_structure()) {
                 echo elgg_view_resource('file_tools/file/list');
                 return false;
             }
             break;
         case 'bulk_download':
             echo elgg_view_resource('file_tools/file/bulk_download');
             return false;
             break;
     }
 }

	<?php 
echo elgg_view('input/longtext', array('name' => 'description', 'value' => $desc));
?>
</div>
<div>
	<label><?php 
echo elgg_echo('tags');
?>
</label>
	<?php 
echo elgg_view('input/tags', array('name' => 'tags', 'value' => $tags));
?>
</div>
<?php 
if (elgg_is_active_plugin('file_tools')) {
    if (file_tools_use_folder_structure()) {
        $parent_guid = 0;
        if ($file = elgg_extract("entity", $vars)) {
            if ($folders = $file->getEntitiesFromRelationship(FILE_TOOLS_RELATIONSHIP, true, 1)) {
                $parent_guid = $folders[0]->getGUID();
            }
        }
        ?>
        <div>
            <label><?php 
        echo elgg_echo("file_tools:forms:edit:parent");
        ?>
<br />
            <?php 
        echo elgg_view("input/folder_select", array("name" => "folder_guid", "value" => $parent_guid));
        ?>

/**
 * Route file
 *
 * @param string $hook         the name of the hook
 * @param string $type         the type of the hook
 * @param array  $return_value current return value
 * @param array  $params       supplied params
 *
 * @return array|false
 */
function theme_haarlem_intranet_file_route_handler($hook, $type, $return_value, $params)
{
    if (empty($return_value) || !is_array($return_value)) {
        return $return_value;
    }
    $page = elgg_extract('segments', $return_value);
    switch ($page[0]) {
        case "owner":
        case "group":
            if (elgg_is_active_plugin('file_tools') && file_tools_use_folder_structure()) {
                $return_value = false;
                include dirname(dirname(__FILE__)) . "/pages/file/list.php";
            }
            break;
    }
    return $return_value;
}

}
$guid = elgg_extract('guid', $vars, null);
$parent_guid = (int) get_input('folder_guid', 0);
if ($guid) {
    $file_label = elgg_echo("file:replace");
    $submit_label = elgg_echo('save');
    // get current parent_guid
    $file = get_entity($guid);
    $folders = $file->getEntitiesFromRelationship(['relationship' => FILE_TOOLS_RELATIONSHIP, 'inverse_relationship' => true, 'limit' => 1]);
    if (!empty($folders)) {
        $parent_guid = $folders[0]->getGUID();
    }
} else {
    $file_label = elgg_echo("file:file");
    $submit_label = elgg_echo('upload');
}
// Get post_max_size and upload_max_filesize
$post_max_size = elgg_get_ini_setting_in_bytes('post_max_size');
$upload_max_filesize = elgg_get_ini_setting_in_bytes('upload_max_filesize');
// Determine the correct value
$max_upload = $upload_max_filesize > $post_max_size ? $post_max_size : $upload_max_filesize;
$upload_limit = elgg_echo('file:upload_limit', array(elgg_format_bytes($max_upload)));
$fields = [['type' => 'file', 'name' => 'upload', 'label' => $file_label, 'help' => $upload_limit, 'value' => $guid, 'required' => !$guid], ['type' => 'text', 'name' => 'title', 'value' => $title, 'label' => elgg_echo('title')], ['type' => 'longtext', 'name' => 'description', 'value' => $desc, 'label' => elgg_echo('description')], ['type' => 'tags', 'name' => 'tags', 'value' => $tags, 'label' => elgg_echo('tags')], ['type' => 'folder_select', 'name' => 'folder_guid', 'value' => $parent_guid, 'label' => elgg_echo('file_tools:forms:edit:parent')], ['type' => 'access', 'name' => 'access_id', 'value' => $access_id, 'entity' => get_entity($guid), 'entity_type' => 'object', 'entity_subtype' => 'file', 'label' => elgg_echo('access')], ['type' => 'hidden', 'name' => 'container_guid', 'value' => $container_guid], ['type' => 'hidden', 'name' => 'file_guid', 'value' => $guid], ['type' => 'submit', 'value' => $submit_label, 'field_class' => 'elgg-foot']];
foreach ($fields as $field) {
    $type = elgg_extract('type', $field, 'text');
    unset($field['type']);
    if ($type == 'folder_select' && !file_tools_use_folder_structure()) {
        continue;
    }
    echo elgg_view_input($type, $field);
}