Archive for the ‘Debug’ Category


Posted: 2017-01-17 in Debug

This works fine in my application.

for i in range(1,20):

But it looks like the it is not picking up both lines when I try to test it in the app inspector or console.
You can only issue single-line commands in the Console/App Inspector Command Windows.


columnName =
sql = 'alter table ? add column ? ? '                                                           
prepare stmt from :sql
execute stmt using :tableName, :columnName, :colDefSql


**** Lianja error ****
execute stmt using :tableName, :columnName, :colDefSql

Data type was expected
Called from procedure – createaltertable at line 222
Called from procedure – dodbupgrade at line 57
Called from procedure – page1_section2_field1_click at line 5

My variables are all good so

?'alter table ' + tableName + ' add column ' + columnName + ' ' + colDefSql

resolves to

alter table TEMPLATE add column ID char(36) not null

Try this:

tablename = "TEMPLATE"
columnName = "ID"
colDefSql = columnName + " char(36) not null"
sql = 'alter table ? add column ? '

prepare stmt from :sql
execute stmt using :tableName, :colDefSql

Going back to your original question, if you issue

set debug on

in the Lianja/VFP command window in the Console or App Inspector before running your code, you can check lianja\debug\debug.txt for errors.

The 3 parameter statement is shown as this (with associated error)

error message: Data type was expected
cmdbuf: alter table [TEMPLATE] add column ID [char(36) not null]

That looks to me like the ‘[]’ string delimiters are being retained and the data type clause therefore not being recognised. I’m not sure if that’s an invalid parameter use or whether this should be handled.

if you find any bugs in Lianja please let us know by submitting a ticket at (Sign in to submit a ticket).

Please include detailed steps to reproduce the problem.
Any required App(s), data and Library files should be
attached to the ticket.
These can be
packaged into a Lianja Package File.
Send cut-down versions of your data where possible – you can create a backup copy for your database in the Data workspace, remove tables or records that are not required for the ticket, then restore your backup.
If you can
reproduce the problem using the sample southwind database, then even better.

If large files are required to reproduce the problem – the maximum ticket attachment size is 20MB – please contact to request an ftp login and instructions on where to upload the files.

If you have more than one problem to report, please submit an individual ticket for each one.

in the log “MouseWheel detected”…

define class clsimage as image
  proc mousewheel(nModifiers, nXpos, nYpos)
    Lianja.writelog("MouseWheel detected")

You need to use ETOS() in the Lianja.writeLog() to convert to a string

Look at the is_object() function in the doc

On the client machine where you have run your installer, have a look at the drive:\lianja\log\log.txt file. This will include the dataDirectory and other directory settings it is using.
Check that this
directory contains the databases that you are expecting.

You can also use the –debug command line switch in your Lianja App Center shortcut, e.g. if installed on C:

C:\lianja\bin\lianjaruntime.exe –debug

This will then output debugging information to the debug.txt and/or debug_client.txt files in the C:\lianja\debug directory.

improved the debug error logging in 2.1 to hep you pinpoint hard to find errors.

The debug.txt file is now versioned for each run of the App Builder or the App Center e.g debug.txt becomes debug_.txt where is the process id of the running executable. Same goes fro debug_client_.txt.

You may want to purge these files periodically.

In Lianja App builder when I click to open ‘Lianja Demo App’ it seems that it tries to open it as indicated by a progress line bar on top bar but it closes the App builder without any error.
1) set debug on, from the console, before you open the Lianja Demo App.
2) go to the debug directory (under Lianja), and open debug.txt.
Hint: get
Notepad++ and leave that file open. That way, when you click on it, Notepad++ will tell you the file has been modified by another program, and ask whether you want to refresh the version.
This way you
don’t have to go click on it every time.

compile your .prg files with the DEBUG keyword (compile myprg debug), and then set debug on,
and you will get a
line-by-line recitation of what fired in what order. And where it stopped firing.

1) compile all your prgs with the debug keyword.
2) on the conig.db file put in: set debug on — then compile it and move it to the deployment conf directory

You will then be able to see what is taking time when you open your app. I think: I haven’t tried this when spawning an app.

Lianja v3.0 now includes a GUI JavaScript debugger.

a note: when the JS debugger appears and has a permanent failure (this was a
missing reference to the lib_xxx.js file), the rest of the app will be locked until you close the debugger.
Makes sense, given that there is no place to go after that error, but could be confusing if you don’t realize it.


Posted: 2017-01-17 in Debug

You can run in “debug” mode and click on the message in the console which will take you to the line which is in error.

Also messageBox() in the web/mobile client is non-blocking and you are displaying it twice.
If you *must*
block the browser window with a modal dialog using alert(“some text”).

If all you want to do is see whats going on use the javascript debugger in the browser (remember to run in debug mode not release mode which will compress the javascript for you).

Also your old friend Lianja.writeLog(“some text”) will write to the javascript console.

It is good practice to always terminate a function code block with a ;

See what is wrong with the function you are trying to evaluate first. You can call it from the JavaScript console in the web client.

Learn how to set break points in the JavaScript debugger in the browser so you can identify the error in your code.

if Lianja cannot evaluate the expression in the client it will automatically try and execute it in the server. That error message is coming from the server.


I clicked the ‘Web App View’, then the ‘Deploy’ option.
Next, I clicked the Preview option and it opened in a browser.
Google Chrome
Clicking this menu item still didn’t seem to do anything.


Press Ctrl+shift+i to open the Developer Tools, then select the Console tab and see if any error are reported when you click the menu item.

In my application, in the console, i see:

mer 29. lug 09:29:09 2015
**** Lianja error ****


mer 29. lug 09:29:10 2015
**** Lianja error ****


mer 29. lug 09:29:12 2015
**** Lianja error ****
Property/Variable 'USER_EDT' not found

I think this is a error occurs inside a try – catch VFP code.
How can I see more detail?
Issue the following settings in the Lianja/VFP Command Window before you open the App then check the debug files.

set debug on
set debugcompile on
set debugtrace on


Posted: 2015-11-07 in Debug

It’s possible to SET DEBUG ON and SET DEBUGTRACE ON when running from the App Center. Simply add it someplace like the Init delagate for the App. That way you’ll at least get the debug files. 

try deleting any .dbo files from your app’s directory and the ./library/ directory and see if that changes the behavior.

Try adding a LIST STATUS TO FILE <filename> before the MESSAGEBOX() and see if everything in there is as you expect.

Have you tried issuing SET DEBUG ON and checking the log in the ./debug/ directory for more information? Issue it in the console before you open your app.

If you could SET DEBUG ON, make your ODBC connection from the console, USE this table, then post the resulting debug file

Can you switch to the lib_search.prg tab in the debugger?
If there is an error in search.rsp, there should be an errorxxxx.mem in lianja\error.

If you open the script in the Script Editor, you can click the Debugger button in the Headerbar to load it into the Debugger. 

It appears that the app debugger (icon in IDE left bottom) is only for debugging Recital script pages (prg?)
yes, the full Desktop App ‘Debug’ debugger is for debugging Lianja/VFP scripts.
You can use the JavaScript command window tab in the Console or the App Inspector

switch debug on in the Console Workspace Lianja/VFP Command Window:

set debug on

Then open an App and attempt an update.
Then in the Console Workspace, Lianja/VFP command window:

display status

If you are debugging an App, just load the App and click the ‘Debug this App’ button in the ModeBar. This will automatically load any custom libraries referenced by the UI Controls. For example, in the lianjacustomcanvas App included in the Lianja App Builder distribution, the ‘page1’ Page references lib_page1.prg and the ‘section2’ Section references lib_page1_section2.prg.

I’ve created a program called myfunc.prg and it is referenced from lib_page1_section2.prg. If I want this to be loaded along with the custom libraries when I open the Debugger, I open it in the Script Editor in the Apps Workspace and click the ‘Open file in Debugger’ button:
Now when I click the ‘Debug this App’ button in the ModeBar, myfunc.prg is also immediately available in the Debugger, not just when it is called while the Debugger is active and ‘Step Into’ used.
With my ‘myfunc.prg’ program loaded in the Debugger, I can set Watch and Break points and continue running the App until one of these is reached.
I click next to the line number to make a line a Breakpoint:
And select/highlight the name of a variable then click ‘Watch’ to set a Watchpoint on a variable:
I can then run the App and the Debugger activates when a Breakpoint or Watchpoint is reached:


At which time, I can step individual lines, or click ‘Run/Continue’ so that the App continues until another Breakpoint or Watchpoint is reached.


If my program file is named “exercise.prg”; then I must use debug excercise.prg?
Set Debug On
Debug excercise.prg
Do excercise.prg
You can, or you can load it into the Debugger like this:


You can enable debugging for the Lianja App Center as follows (please remember to switch it off after you’ve tracked down the error):
Create a text file called ‘config.db’ in C:\Lianja\conf and edit it to contain the line

set debug on

This is the equivalent of setting debug on from the Console Workspace in the Lianja App Builder, so check for any information logged into C:\Lianja\debug\*.txt.
I should also mention that that will be a system-wide setting while enabled – so will also apply to a Lianja App Builder on the same machine. 

In the Console, switch debug logging on:

set debug on

Then do your updates, exit the App Builder and have a look at the files in Lianja\debug to see if any errors are reported.

Can you put a LIST STATUS just before that to show what tables are already open? 

Specify a target for the SELECT – at the moment it will just be going to the Console Output Window as standard output. 
For example, save it to a cursor:

FROM bantam_stats!penalties ;
WHERE teamid = intTeamID AND playernumber = intPlayerNumber;
into cursor cPenalties

or into a memory variable:

FROM bantam_stats!penalties ;
WHERE teamid = intTeamID AND playernumber = intPlayerNumber into cPenaltydesc

there is no debugger for javascript.
You can use Lianja.writeOutput() then open the app inspector, switch to runtime mode then look in the events tab and the output.

when you SET DEBUG ON in the console, you can look in the c:\lianja\debug\debug_client.txt file which has a trace of all property set/get and method calls. It can help to identify problems.

Also if you


and put 

DEBUGOUT "some message"

these will be included in the debug,txt file also which should help to track the problem down.

Try this in the console:

do dadress.scp

Or close the App and this in the Debug Console:

do c:\Lianja\apps\aim\daddress.scp

To see how events are being dispatched, in the console workspace type:


then you can look in c:\lianja\debug\debug_client.txt to see if the events are being dispatched or not.

Not wanting to sound like a broken record, but if you SET DEBUG ON and run you code then exit Lianja and look in the debug_client.txt file you will be able to see if the object was destroyed and the ActiveX destroyed alongside it.
Try assigning .f. To it rather than .null.

if you are having difficulties getting this to work then SET DEBUG ON and test your update. If it does not work look in debug_client.txt. If you can’t figure it out then submit a ticket attaching debug_client.txt, the output from LIST STATUS in the console and your delegate code that is performing the update.

Open up the App Inspector and watch the events at runtime when you open the App with Lianja.openApp().

The console is designed to run interactive single line commands.
The simplest way to write complete multi-line scripts in the console is to type:

ed myscript

You will now be in the script editor where you can type in as much as you want.
next, just select the “Console” workspace (no need to save it is done automatically) then type:

do myscript

You can’t debug complied server pages which is what you are trying to do.
Server pages ( .rsp pages ) are just in time compiled producing a .rso object file which is executed.
Server pages typically generate HTML5/Javascript. What is it you are using that for in a showdialog().

Ok so that’s a virtual table you are relating to?




will tell you the alias names which are referenced in the relationship and show you the column names.

Look in the console and see if there are any errors, also LIST STATUS will show what indexes were created to handle the related sections. 

In most cases I have synonyms for them so messagebox() and messageBox() both work.
Screen Shot 2014-08-15 at 8.39.46 PM