/**
  * Get the columns from a database table.
  *
  * @param   string  $tableName  Table name. If null current table is used
  *
  * @return  mixed  An array of the field names, or false if an error occurs.
  */
 public function getTableFields($tableName = null)
 {
     // Should I load the cached data?
     $useCache = array_key_exists('use_table_cache', $this->config) ? $this->config['use_table_cache'] : false;
     // Make sure we have a list of tables in this db
     if (empty(self::$tableCache)) {
         if ($useCache) {
             // Try to load table cache from a cache file
             $cacheData = FOFPlatform::getInstance()->getCache('tables', null);
             // Unserialise the cached data, or set the table cache to empty
             // if the cache data wasn't loaded.
             if (!is_null($cacheData)) {
                 self::$tableCache = json_decode($cacheData, true);
             } else {
                 self::$tableCache = array();
             }
         }
         // This check is true if the cache data doesn't exist / is not loaded
         if (empty(self::$tableCache)) {
             self::$tableCache = $this->_db->getTableList();
             if ($useCache) {
                 FOFPlatform::getInstance()->setCache('tables', json_encode(self::$tableCache));
             }
         }
     }
     // Make sure the cached table fields cache is loaded
     if (empty(self::$tableFieldCache)) {
         if ($useCache) {
             // Try to load table cache from a cache file
             $cacheData = FOFPlatform::getInstance()->getCache('tablefields', null);
             // Unserialise the cached data, or set to empty if the cache
             // data wasn't loaded.
             if (!is_null($cacheData)) {
                 $decoded = json_decode($cacheData, true);
                 $tableCache = array();
                 if (count($decoded)) {
                     foreach ($decoded as $myTableName => $tableFields) {
                         $temp = array();
                         if (is_array($tableFields)) {
                             foreach ($tableFields as $field => $def) {
                                 $temp[$field] = (object) $def;
                             }
                             $tableCache[$myTableName] = $temp;
                         } elseif (is_object($tableFields) || is_bool($tableFields)) {
                             $tableCache[$myTableName] = $tableFields;
                         }
                     }
                 }
                 self::$tableFieldCache = $tableCache;
             } else {
                 self::$tableFieldCache = array();
             }
         }
     }
     if (!$tableName) {
         $tableName = $this->_tbl;
     }
     // Try to load again column specifications if the table is not loaded OR if it's loaded and
     // the previous call returned an error
     if (!array_key_exists($tableName, self::$tableFieldCache) || isset(self::$tableFieldCache[$tableName]) && !self::$tableFieldCache[$tableName]) {
         // Lookup the fields for this table only once.
         $name = $tableName;
         $prefix = $this->_db->getPrefix();
         if (substr($name, 0, 3) == '#__') {
             $checkName = $prefix . substr($name, 3);
         } else {
             $checkName = $name;
         }
         if (!in_array($checkName, self::$tableCache)) {
             // The table doesn't exist. Return false.
             self::$tableFieldCache[$tableName] = false;
         } elseif (version_compare(JVERSION, '3.0', 'ge')) {
             $fields = $this->_db->getTableColumns($name, false);
             if (empty($fields)) {
                 $fields = false;
             }
             self::$tableFieldCache[$tableName] = $fields;
         } else {
             $fields = $this->_db->getTableFields($name, false);
             if (!isset($fields[$name])) {
                 $fields = false;
             }
             self::$tableFieldCache[$tableName] = $fields[$name];
         }
         // PostgreSQL date type compatibility
         if ($this->_db->name == 'postgresql' && self::$tableFieldCache[$tableName] != false) {
             foreach (self::$tableFieldCache[$tableName] as $field) {
                 if (strtolower($field->type) == 'timestamp without time zone') {
                     if (stristr($field->Default, '\'::timestamp without time zone')) {
                         list($date, $junk) = explode('::', $field->Default, 2);
                         $field->Default = trim($date, "'");
                     }
                 }
             }
         }
         // Save the data for this table into the cache
         if ($useCache) {
             $cacheData = FOFPlatform::getInstance()->setCache('tablefields', json_encode(self::$tableFieldCache));
         }
     }
     return self::$tableFieldCache[$tableName];
 }