| Debug Service Debug service is really useful in the
development environment. Even though there is a
default debugging facility, sometimes, you may
want to do fast debugging instead of going step
by step in the debug painter. For example, you
may want to display a message box when an event
router fails delivering the message, but you
don’t want to display in the production
environment. In that case, you can turn on the
debugging service as shown below:
gnv_app.of_SetDebug(TRUE)
The above code creates the
debug service. This code will also display a
message box when the a message is not processed
(basically the message sent using the menu
message router). There are two basic debug
services are available. One is DataWindow
specific and the other one is SQL specific. For
example, you want to see all the SQL statements
that are being generated by PowerBuilder to send
to the database, then, you need to write the
following code:
gnv_App.inv_debug.of_SetSQLSpy(
TRUE )
The above code turns on the SQL
spy service. Now, you have two options, either
log all the SQL statements to a log file or
display the SQL statements in a popup window. If
you would like to log the SQL, you need to call of_SetLogFile() function with the file name as the
parameter.
gnv_appthis.inv_debug.inv_sqlspy.of_SetLogFile(
"SQLSpy.log" )
To display the SQLSpy popup
window, call of_OpenSQLSpy(TRUE) function:
gnv_app.inv_debug.inv_sqlspy.of_OpenSQLSpy(
TRUE )
PFC SQL Spy Window.
The first check box in the
above picture won’t be displayed with the
above code. By default, the SQL spy utility works
in the batch mode, that means, all the SQL
statements are displayed/logged. It doesn’t
allow you to change them before they actually get
executed. In any situation if you would like to
inspect the actual SQL statement before it is
actually executed, you need to turn of the batch
mode and turn on the inspect mode:
gnv_app.inv_debug.inv_sqlspy.of_SetBatchMode(
FALSE )
gnv_app.inv_debug.inv_sqlspy.of_SetAllowInspect(
TRUE )
Call those two scripts before
you open the SQLSpy window. Now, if you run the
application, you will still see all those SQL
statements. Say, you open the w_product_master
window and retrieve the data from the database.
You will see the SELECT statement in the SQLSpy
window. You must be wondering why the utility
didn’t prompt you for changing the SQL. This
utility doesn’t allow you changing the SQL
while it retrieves the data. However, you can
change the SQL before you update/delete/insert.
For ex, if you change the description of one of
the product and save the changes, PFC will prompt
you as shown below:
PFC SQL Spy Inspect Window.
In this window, you can do
changes to the SQL statements. Similar to the
debug painter, you can execute one SQL statement
at a time by using the "Step" button,
OR you can ask the SQL Spy to execute all the SQL
statements after the current one without
prompting you. You can use SQLSpy for DataWindows
and embedded/dynamic SQL also.
Sometimes, you need to debug
the DataWindow, i.e., finding out the row/item
status, font/color/any other expressions and so
on. In that case, SQLSpy is not useful, since it
deals with SQL only. For this purpose, you need
to use w_dwDebugger window. We couldn’t find
w_dwDebugger window in any of the PFE libraries
(might be a mistake done at Powersoft). Create a
window by inheriting from
"pfc_w_dwDebugger" window and save it
as "w_dwDebugger". You don’t have
to change anything. Whenever you want to debug
the DataWindow, then write the following code.
For example, say, you found some funny things are
going on when the user clicks with the right
mouse button and you want to debug at that
moment. Then write the following code to the
rButtonDown event:
s_dwdebugger
lstr_parm
lstr_parm.DW_obj =
dw_product
lstr_parm.Tr_obj = SQLCA
OpenWithParm(w_dwdebugger, lstr_parm)
You will see the following
window:
PFC debug window for a DataWindow.
In this window, you can see the
values of all the attributes of the selected
row/column. You can also see rows from the
deleted/filtered buffers. If you change the value
of any attribute in this window, PFC
automatically applies to the actual DataWindow,
as soon as you tab out of the changed field. In
the above picture, we changed the border and as
soon as we press tab, PFC changed the border of
that field. Cool, we didn’t write the modify() function, PFC took care of it
internally.
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