Run in debug mode – PB Docs 2019 – PowerBuilder Library

Run in
debug mode

Where you are

Set a watch and a
conditional breakpoint

Now you run the application in debug mode. You step through the code
line by line.

About the Step buttons

You can use either Step In or Step Over to step through an
application one statement at a time. They have the same result except
when the next statement contains a call to a function.

Use Step Over to execute the function as a single statement. Use
Step In if you want to step into a function and examine the effects of
each statement in the function.

If you have stepped into a function, you can use Step Out to execute
the rest of the function as a single step and return to the next statement
in the script that called the function.

Click the Start button () in PainterBar1

or

Select Debug>Start pbtutor from the menu bar.

The application starts and runs until it hits a breakpoint (in
this case, the call to the assignment statement for the toolbar title
for sheet windows).

You return to the Debug window, with the line containing the
breakpoint displayed. The yellow arrow cursor means that this line
contains the next statement to be executed.
Click the Global tab in the lower-left stack.

The Global Variables view displays.
Double-click transaction sqlca.

Find the DBMS property, which has a String datatype.

Notice that this property does not yet have a value associated
with it because the Debugger interrupted execution before the
ProfileString function executed.
To execute the next statement, click the Step In button
() in PainterBar1

or

Select Debug>Step In from the menu bar.

The application starts execution of the Open event for the MDI
frame window.
Use Step In or Step Over to step through the code until you
reach this statement in the script for the frame window Open
event:

PowerBuilder

open(w_welcome)

1

open(w_welcome)

After PowerBuilder finishes executing this statement, the login
window displays and the Debug window is minimized.

The Open event for the frame window also has a posted call to
the ue_postopen function (that you stepped through without examining).
This function in turn includes code that starts the processing of a
chain of sheet manager functions. These functions are processed at the
end of the script for the Open event, after the login window
displays.
Click Step Over () until the login window displays and the
Debugger is minimized.

Type dba in the User ID box of the login window.

Type sql in the Password box and click OK.

You return to the Debug window. The yellow arrow in the Source
view points to the next executable statement, the CREATE statement for
the connection service object. This is the first executable line in
the script for the Clicked event of the cb_ok command button.
Select the Call Stack tab in the lower-right stack.

The yellow arrow in the Call Stack view indicates the current
location in the call stack. If you double-click another line in the
stack, the Source and Variables views change to display the context of
that line, and a green arrow indicates the line in the Source view. If
you then single-click another line in the stack, a green arrow
displays in the Call Stack view to indicate the line for which context
is displayed. When you continue to step through the code, the Source
and Variables views return to the current context.
Click the Step In button.

The Debugger takes you to the script for the Constructor event
of the connection service object.
Click the Step Out button ().
Click the Global tab in the lower-left stack.

Look again at the Transaction object properties.

You step out of the Constructor event in a single step and
return to the script for the OK button Clicked event. Now the value of
sqlcode has changed, and the sqlerrortext and DBMS property have
values, but the UserID, DBPass, and DBParm properties do not.

The values were assigned during execution of the Constructor
event of the connection service object after the of_GetConnectionInfo
function returned information from the INI file, but because you
commented out the lines in the code for the UserID, DBPass, and DBParm
properties, these values were not retrieved.
Click on the Local tab in the lower-left stack.

The local variables for the Clicked script have not yet been
assigned values.
Use the Step In button to step through the three assignment
statements for the local variables.

As you step through each statement, you can check that the
values assigned to the local variables are what you expected.
Click again on the Global tab in the lower-left stack and expand
the Transaction object.

Use the Step In button to step through the three lines that
instantiate the Transaction object (SQLCA) with user-entry values for
UserID, DBPass, and DBParm.

As you step through each statement, you can check that the
values you entered in the login window are being assigned to the
Transaction object. You are still not connected to the database until
the connection service object of_Connect function is executed.
Click the Continue button () in PainterBar1.
The Continue button resumes execution until the next breakpoint.
The database connection is established, the login window closes, and
the MDI frame for your application displays. The application is
waiting for user input.
Select File>Report>Maintain Customers from the menu
bar.

The application continues until it reaches the line in the
RowFocusChanged event that contains the next breakpoint you
added.

The RowFocusChanged event for a DataWindow occurs before the
DataWindow is displayed. For this reason, execution stops before the
Customer window is opened.