Understading Zabbix building blocks

[rohitist]

Hi,

Can anyone please help me to understand what below shown constants mean (i.e.z T_ZBX_STR, O_OPT etc):

$fields = array(
	'type' =>				array(T_ZBX_STR, O_OPT, null,	IN('"'.ZBX_DB_MYSQL.'","'.ZBX_DB_POSTGRESQL.'","'.ZBX_DB_ORACLE.'","'.ZBX_DB_DB2.'","'.ZBX_DB_SQLITE3.'"'), null),
	'server' =>				array(T_ZBX_STR, O_OPT, null,	null,				null),
	'port' =>				array(T_ZBX_INT, O_OPT, null,	BETWEEN(0, 65535),	null, _('Database port')),
	'database' =>			array(T_ZBX_STR, O_OPT, null,	NOT_EMPTY,			null, _('Database name')),
	'user' =>				array(T_ZBX_STR, O_OPT, null,	null,				null),
	'password' =>			array(T_ZBX_STR, O_OPT, null,	null, 				null),
	'schema' =>				array(T_ZBX_STR, O_OPT, null,	null, 				null),
	'zbx_server' =>			array(T_ZBX_STR, O_OPT, null,	null,				null),
	'zbx_server_name' =>	array(T_ZBX_STR, O_OPT, null,	null,				null),
	'zbx_server_port' =>	array(T_ZBX_INT, O_OPT, null,	BETWEEN(0, 65535),	null, _('Port')),
	'message' =>			array(T_ZBX_STR, O_OPT, null,	null,				null),
	// actions
	'save_config' =>		array(T_ZBX_STR, O_OPT, P_SYS,	null,				null),
	'retry' =>				array(T_ZBX_STR, O_OPT, P_SYS,	null,				null),
	'cancel' =>				array(T_ZBX_STR, O_OPT, P_SYS,	null,				null),
	'finish' =>				array(T_ZBX_STR, O_OPT, P_SYS,	null,				null),
	'next' =>				array(T_ZBX_STR, O_OPT, P_SYS,	null,				null),
	'back' =>				array(T_ZBX_STR, O_OPT, P_SYS,	null,				null),
	'form' =>				array(T_ZBX_STR, O_OPT, P_SYS,	null,				null),
	'form_refresh' =>		array(T_ZBX_INT, O_OPT, null,	null,				null)
);

The reason why i want to understand is that I want to bring new custom features in ZABBIX UI for our organizational needs.

Please help.

Thanks in advance.