Hi,

I have a print dialog, shown before the report is generated. The user can make some selections. Based on that, I want to set the value of a global variable, then use that variable to decide if a column of data must be visible or not.

I've used File -> Variable List to define a new variable (just the name).

I then double clicked on a header memo field and enabled the Script checkbox, and typed in the following code in the Script box:

===================================
if [ HideKlas] = '0' then
  Visible := True
else
  Visible := False;
===================================

In my *.pas unit I temporarily tried to set a hard-coded value of the "HideKlas" variable to see what happens in the report. I tried both the values '0' and '1'.

===================================
If FRPrint.PrepareReport then
begin
  FRPrint.Variables.Values['HideKlas'] := '1';  // for testing only
  FRPrint.Preview := FAfdrukForm.PrintPanel;
  FRPrint.ShowPreparedReport;
end;
===================================

No matter what I do, the header (memo) field is now _always hidden_. Changing the hard-coded value of the variable doesn't seem to make any difference.

Before any of the above script changes the report worked, and the header text was visible. But I can't seem to make that visibility a dynamic option.

Any tips would be much appreciated.

Regards,
- Graeme -

I've even tried removing the "HideKlas" variable completely, then do something like this in the .pas unit.

  (FRPrint.Pages.Pages[0].FindObject('memo5') as TfrMemoView).Visible :=
False;
  FRPrint.Preview := FAfdrukForm.PrintPanel;
  FRPrint.ShowPreparedReport;

But not even that works. In this case the memo5 is always shown, as if I didn't have that extra line of code.

Regards,
- Graeme -

Graeme Geldenhuys wrote

I've used File -> Variable List to define a new variable (just the name).

Digging deeper into the LazReport code, I finally found the solution.

Even though you setup a variable, you must not refer to it via the Scripts.Values[] or Variables.Values[] properties. Go figure!

Instead you use the Values.FindVariables() method.

  FRPrint.Values.FindVariable('HideKlas').Field := '1';

For more details of what I've done, see the Lazarus Forum post. http://forum.lazarus.freepascal.org/index.php/topic,28922.0.html

Now this begs the question... What the hell does Scripts.Values[] and Variables.Values[] actually do?

Regards,
- Graeme -

Those are not global variables. They are report variables.

I think the easier way to modify global variables is through the frVariables object
ej.

frVariables['HideKlas'] := 1;

They do the same thing they do for any TStrings list, ie. Assign values to supposedly existing "names" , for they to work you have to have a list like:

name1=value1
name2=value2
etc.

But in LazReport this TStrings list functionality is not used.

Report.Variables holds the list of variables and variables categories that you have defined in the Report (usually using the report designer gui). Variables categories can only be used as distinctive tags for a group of variables, and I guess that is the reason why there are a Values object too, which btw has a list of only variables.

I was not able to find a Report.Scripts property or field, maybe you mean Report.Script? in that case supposedly it holds the script to be run as "BeforePrint" script.

Jesus Reyes A.

Hi Jesus,

Thanks for taking the time to reply. It is much appreciated.

Jesus Reyes A. wrote

Those are not global variables. They are report variables.

In the context of a report, they are the same thing to me. You define a variable via the Report GUI Designer (I still don't know how to do it from code), that variable is then available for use anywhere in your report. ie: gloabal ;-)

I'll take a look at that, thanks.

But in LazReport this TStrings list functionality is not used.

Huh? You lot me there. So if they are not used, why do those properties still exist in TfrReport?

I was not able to find a Report.Scripts property or field, maybe you mean Report.Script?

Sorry, it was a typo. I meant Report.Script.

As far as I understand, LazReport is based on some open source version of FastReport. Due to the lack of documentation (or updated documentation) of LazReport, I looked at the documentation for FastReport and tried to use some if what it suggests. But it seems much of it doesn't translate to LazReport.

Here is the URL of FastReport I looked at.

https://www.fast-report.com/documentation/ProgMan/index.html?adding_a_variable.htm

I worked through the whole "Working with a list of variables" section.

Regards,
- Graeme -

En Wed, 01 Jul 2015 17:52:57 -0500, Graeme Geldenhuys escribi?:

:)
Yes, you can consider them as global if you so desire. However they exists only in your report, where they were defined. The frVariables list however can be used by n-number of reports in your application. This is why I think of them as "global"

It seems possible to have report and global variables named the same, however I have not investigated who takes precedence, I would guess report variables are found first, but I'm not sure TBH.

They are not specific to LazReport, this is basic functionality of every TStringList, just because they descend from TStrings. Values and Names are public properties of TStrings, how can one hide those properties in a instance of TStringList?, you can't, so LazReport also can't. :D

Yes, probably, however one could find that they have also many things on common.

frxReport1.Variables['My Variable 1'] := 10; and likewise
Variable := frxReport1.Variables.Add and
Variable := frxReport1.Variables.Insert(1);

Wouldn't work on LazReport as here frxReport1.Variables is just a mere mortal TStringList which already have a default property: Strings[] indexed by integer, This part is in LazReport a little mess :), I think FastReport guys noted this and they fixed the situation in FastReport.

Regards, - Graeme -