Search::computeComplexJoinID PHP Method

    static function computeComplexJoinID(array $joinparams)
    {
        $complexjoin = '';
        if (isset($joinparams['condition'])) {
            $complexjoin .= $joinparams['condition'];
        }
        // For jointype == child
        if (isset($joinparams['jointype']) && $joinparams['jointype'] == 'child' && isset($joinparams['linkfield'])) {
            $complexjoin .= $joinparams['linkfield'];
        }
        if (isset($joinparams['beforejoin'])) {
            if (isset($joinparams['beforejoin']['table'])) {
                $joinparams['beforejoin'] = array($joinparams['beforejoin']);
            }
            foreach ($joinparams['beforejoin'] as $tab) {
                if (isset($tab['table'])) {
                    $complexjoin .= $tab['table'];
                }
                if (isset($tab['joinparams']) && isset($tab['joinparams']['condition'])) {
                    $complexjoin .= $tab['joinparams']['condition'];
                }
            }
        }
        if (!empty($complexjoin)) {
            $complexjoin = md5($complexjoin);
        }
        return $complexjoin;
    }

function plugin_projet_addSelect($type, $ID, $num)
{
    $searchopt =& Search::getOptions($type);
    $table = $searchopt[$ID]["table"];
    $field = $searchopt[$ID]["field"];
    $addtable = "";
    $NAME = "ITEM";
    $complexjoin = '';
    if (isset($searchopt[$ID]['joinparams'])) {
        $complexjoin = Search::computeComplexJoinID($searchopt[$ID]['joinparams']);
    }
    if (($table != getTableForItemType($type) || !empty($complexjoin)) && $searchopt[$ID]["linkfield"] != getForeignKeyFieldForTable($table)) {
        $addtable .= "_" . $searchopt[$ID]["linkfield"];
    }
    if (!empty($complexjoin)) {
        $addtable .= "_" . $complexjoin;
    }
    // Example of standard Select clause but use it ONLY for specific Select
    // No need of the function if you do not have specific cases
    switch ($type) {
        case 'PluginProjetProjet':
            switch ($table . "." . $field) {
                case "glpi_plugin_projet_projetstates.name":
                    return "`" . $table . "`.`" . $field . "` AS ITEM_{$num}, `" . $table . "`.`id` AS ITEM_" . $num . "_2, ";
                    break;
                case "glpi_plugin_projet_projets_projets.plugin_projet_projets_id_1":
                    return " GROUP_CONCAT(`{$table}{$addtable}`.`plugin_projet_projets_id_1` SEPARATOR '\$\$\$\$')\n                           AS " . $NAME . "_{$num},\n                     GROUP_CONCAT(`{$table}{$addtable}`.`plugin_projet_projets_id_2` SEPARATOR '\$\$\$\$')\n                           AS " . $NAME . "_" . $num . "_2, ";
                    break;
            }
            return "";
            break;
        case 'PluginProjetProjetState':
            switch ($table . "." . $field) {
                case "glpi_plugin_projet_projetstates.color":
                    return "`" . $table . "`.`" . $field . "` AS ITEM_{$num}, `" . $table . "`.`id` AS ITEM_" . $num . "_2, ";
                    break;
            }
            return "";
            break;
        case 'PluginProjetTask':
            switch ($table . "." . $field) {
                case "glpi_plugin_projet_tasks_tasks.plugin_projet_tasks_id_1":
                    return " GROUP_CONCAT(`{$table}{$addtable}`.`plugin_projet_tasks_id_1` SEPARATOR '\$\$\$\$')\n                           AS " . $NAME . "_{$num},\n                     GROUP_CONCAT(`{$table}{$addtable}`.`plugin_projet_tasks_id_2` SEPARATOR '\$\$\$\$')\n                           AS " . $NAME . "_" . $num . "_2, ";
                    break;
                case "glpi_contacts.name":
                    return "`" . $table . "`.`id` AS ITEM_{$num}, `" . $table . "`.`name` AS contacts_name,\n                        `" . $table . "`.`firstname` AS contacts_firstname, ";
                    break;
                case "glpi_plugin_projet_taskstates.name":
                    return "`" . $table . "`.`" . $field . "` AS ITEM_{$num}, `" . $table . "`.`id` AS ITEM_" . $num . "_2, ";
                    break;
            }
            return "";
            break;
        case 'PluginProjetTaskState':
            switch ($table . "." . $field) {
                case "glpi_plugin_projet_taskstates.color":
                    return "`" . $table . "`.`" . $field . "` AS ITEM_{$num}, `" . $table . "`.`id` AS ITEM_" . $num . "_2, ";
                    break;
            }
            return "";
            break;
    }
    return "";
}