Is there a Debugging Window on Lazarus?

[Edson]

In console mode, we can use a simple WriteLn() for output some value to screen.
But in Windows Apps, it doesn't work.
I am looking for some easy way for show strings on Windows Apps (No need for to use a file or to config an environment variable, or to use command line, like DebugLn need).

[Martin_fr]

Compile the app as console app.

There is a checkbox "win32 gui application"
 (in "Project options"  exact place depends on which version you have, in 1.3 it is "Config and Target")

Uncheck it, and you get a console window.

Or write to StdErr, and watch the debug event log.

[Edson]

Thanks Martin,

I can see now, the output on the console window, when I use writeln().

But it's annoying, when I get an error on execution time when I check again the "win32 gui application".  I must comment all the writeln() or use and conditional directive, for all the writeln().

[Martin_fr]

use debugln instead.

It checks for the availability of STDOUT.

And you can change the uses clause

LazLoggerDummy : all debugln are just empty methods, so your code will not do anything (well fpc may leave a few calls to an empty method)

LazLogger : fully functional. Also adds check for commandline options --debug-log and --debug-enable (can be configured

LazLoggerBase : inactive.

LCLProc : nor sure, same as LazLogger or LazLoggerBase


---
LazLoggerBase  is supposed to be used in most units.

 Then as soon as you add LazLogger to ONE unit all LazLoggerBase become active.

[Edson]

It seems that "LazLogger" is very complete.

But, does debugLn() have a window for show the output?

[Leledumbo]

But, does debugLn() have a window for show the output?

AFAIK, debug server (in tools menu) will show the output of debugln.

[Martin_fr]

Not sure which package debugserver is, it is not there by default.
There actually is a special write to debugserver command, but I do not remember.



Debugln writes to STDOUT (same as writeln). The difference isn that it does not crash, if there is no console.

And it can be redirected to a logfile if wanted. Together with a "tail" application that can also be used.

[Leledumbo]

Not sure which package debugserver is, it is not there by default.

No package required, it's there: $LazarusDir()/tools/debugserver/debugserver$ExeExt()
Strange, I remember never touch anything and it is there from the start.

[Martin_fr]

See picture. Tools menu of a fresh install. No debugserver entry

[Edson]

It's not in tool menú.

It's an executable that must be in:  $LazarusDir()/tools/debugserver/

But in my Lazarus, it doesn´t exist. I had to compile the project that was in that place, for getting the executable.

Once executed, the "debugserver.exe" work fine. It show the message of my app, if I use the unit "dbugintf" and call the function "SendDebug()".

But it need, to have the debugserver.exe, always running. If I stop the process, it give me an Error on execution time. (It's the same of using WriteLn on no "win32 gui application" mode).

[Leledumbo]

OK maybe a long time ago I put it in my tools menu as custom tool, so I can call it conveniently. You can also use event log window, using TEventLog as debugging aid.

[Edson]

I probed the TEventLog object, and it worked, but honestly it's a complicated way for view debugging message. It has a lot of unuseful information.

Until now I can see that "There is not a simple way for viewing message on a debugging window."

I was expecting to have some like:

uses ..., debugWin;
...
debug('hello');
...

And no more.

I think it's necessary to have at least a simple Debug Windows on Lazarus, considering that we don't have a good debugger.

[Martin_fr]

Personally I use debugln.

If you define buildmodes, the changing between with and without console window is just making a selection in a dropdown on the main toolbar (no dialog, immediately reachable)

debugln does not fail if there is no console,

And it can be eliminated (by substituting the unit) for release builds.

---
The biggest shortcoming of the debugger imho is the lack of function calling (and with that the ability to see properties).
It has rarely ever affected me. Normally I know the underlying field, and can watch this.

Also make sure to use DWARF, so
  property FOO: Integer read FFOO;
will work (no function, direct to field)

[Edson]

Thanks Martin,

it's a good option, to use debugLn with "Build Modes".  I think I can use that way too. However It's necessary to configure for each project, a little extra job.

Probably later I will try to make my own debug Window. I don't hate black console window, but i think it doesn't fit at the Lazarus standar.

I think Lazarus is a great IDE, but has so many options that anyone can confuse at the first time. Probably could have a some different default configuration.
Moreover, I see a lack of documentation on Lazarus or if we have, it's not correctly organized.

[GeertVc]

Personally I use debugln.

If you define buildmodes, the changing between with and without console window is just making a selection in a dropdown on the main toolbar (no dialog, immediately reachable)

debugln does not fail if there is no console,

And it can be eliminated (by substituting the unit) for release builds.

I know this is an old thread, but I just stepped in into Lazarus and stumbled upon the same.  Build mode is a nice alternative, as is the debugserver alternative.  However, it's anyhow a pitty that WriteLn() doesn't work with Windows GUI's or that DebugLn() is not rerouted to the default available Messages window...