Oracle Apex - Debug (Messages)

About

The debug facility displays application processing details through messages that can be:

enabled (to a certain information level)
disabled
added
removed

Articles Related

Level

Definition

Level	Name	Description	PL/SQL 4.2 Message
1	error	critical error	Error
2	warn	less critical error	Warn
4	info	default level if debugging is enabled (for example, used by apex_application.debug)	Info
5	app_enter	application: messages when procedures/functions are entered	Enter
6	app_trace	application: other messages within procedures/functions	Trace
8	engine_enter	Application Express engine: messages when procedures/functions are entered
9	engine_trace	Application Express engine: other messages within procedures/functions

Initialization

URL

Through the Apex URL

Valid values for the DEBUG flag include:

Values	Description
LEVELn	Enable debug with the level n of debug detail (between 1 and 9)
YES	Enable debug with the level 4
NO	Disable debug

API

Enabled:

BEGIN
    APEX_DEBUG.ENABLE(apex_debug.c_log_level_info);
    -- Before 4.2: APEX_DEBUG_MESSAGE.ENABLE_DEBUG_MESSAGES (apex_debug.c_log_level_info);
END;

where:

apex_debug.c_log_level_info is a constant of the debug package

Disabled

BEGIN
    APEX_DEBUG.DISABLE();
END;

Reference

You can reference the Debug level flag using the following syntax:

Short substitution string: &DEBUG.
PL/SQL: V('DEBUG')
Bind variable: :DEBUG

API

Package:

since 4.2 APEX_DEBUG
before APEX_DEBUG_MESSAGE

This package provides APIs to instrument and debug PL/SQL code:

contained within your Application Express application
as well as in database stored procedures and functions.

Messages

Add

The MESSAGE Procedure

since 4.2

is the main procedure to add messages to different levels.

There is also shortcut procedure for each level

Example: Enter: level 5

procedure foo ( 
    p_widget_id in number, 
    p_additional_data in varchar2, 
    p_emp_rec in emp%rowtype ) 
is 
begin 
    apex_debug.enter('foo', 
        'p_widget_id' , p_widget_id, 
        'p_additional_data', p_additional_data, 
        'p_emp_rec.id' , p_emp_rec.id ); 
....do something.... 
end foo;

Remove

See the following procedure:

REMOVE_DEBUG_BY_AGE Procedure
REMOVE_DEBUG_BY_APP Procedure
REMOVE_DEBUG_BY_VIEW Procedure
REMOVE_SESSION_MESSAGES Procedure

View

metadata view: APEX_DEBUG_MESSAGES