Working in the IDE Environment Reusing Forms
lazarus / 13-General

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flywire · 2015-03-04 01:51

How do you manage working on a program and testing a piece of code?

For example, I am working on a program and I find some sample code
that has something that I would like to include in my program.
Currently I add a bodgy procedure or close my program, load the sample
code into a new test program, copy the line(s) that I like then reopen
my program and insert them.

I would prefer a process where I could test some code without
affecting my current program until I am ready to change it.

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Leledumbo · 2015-03-04 05:41

open in another lazarus instance

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flywire · 2015-03-24 11:53

I seem to be plagued by ghosts in the IDE.

I have MMW.lpr, Unit1.pas, Unit3.pas and Form1.lfm in the IDE

How do I get the following error:

Code: [Select]Compile Project, Target: MMW.exe: Exit code 1, Errors: 1
unit3.pas(27,0) Error: Can't open resource file "C:\Users\Fearless
User\Documents\Lazarus\MMW\unit3.lfm"

The first time I saw error was when I added Form1.lfm to a project but
it came in as unit4.pas rather than a form. I have since deleted
everything in the directory and restarted but the unit2.lfm ghost
returns.

Version #:1.4RC2, Date: 2015-03-01, FPC Version: 2.6.4, SVN Revision:
48058, i386-win32-win32/win64 Intel Core duo running Win7

Edit: Deleted the units because they only confused.

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flywire · 2015-03-24 12:01

It has got something to do with the {$R *.lfm} culpret in unit3.pas.

How do I add an old form to a project?

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JuhaManninen · 2015-03-24 12:46

Quote from: flywire on March 24, 2015, 01:01:22 pmIt has got something
to do with the {$R *.lfm} culpret in unit3.pas.
How do I add an old form to a project?

Add it to a GUI LCL application, not to a command line program.

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flywire · 2015-04-14 08:20

Quote from: JuhaManninen on March 24, 2015, 01:46:41 pmAdd it to a GUI
LCL application, not to a command line program.
Can someone explain? I am currently just putting the MMW.lpr,
Unit1.pas, Unit2.pas and Form1.lfm in an empty directory then double
clicking on MMW.lpr to open the program in the IDE. The form gets
attached to the Source Editor not the Project Forms.


Version #:1.4RC2, Date: 2015-03-01, FPC Version: 2.6.4, SVN Revision:
48058, i386-win32-win32/win64 Intel Core duo running Win7

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howardpc · 2015-04-14 08:43

Quote from: flywire on April 14, 2015, 10:20:31 amCan someone explain?
I am currently just putting the MMW.lpr, Unit1.pas, Unit2.pas and
Form1.lfm in an empty directory then double clicking on MMW.lpr to
open the program in the IDE.

Without adding Unit2.lfm, the Lazarus form streaming system has no way
to instantiate a valid TForm1. Its property values are set at load
time.
Your unit2 (or is it Unit3 - your posts are inconsistent?) includes
the instruction:
{$R *.lfm}

However, there is no unit2.lfm to read. Hence the loading error. The
message is clear and to the point. You must either add the appropriate
.lfm file, or comment the read directive thus:
//{$R *.lfm}
and build a resourceless form yourself starting with
TForm1.CreateNew().

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flywire · 2015-04-14 11:50

Sorry, this is not clear yet.

1. The original post is six weeks old and I can't explain the contents
of those two units as they don't contain what I expected in them which
must have something to do with my attempt to bring the form in.

2. The current situation is that I have the three files in reply#6 htt
p://forum.lazarus.freepascal.org/index.php/topic,27584.msg174478.html#
msg174478.

3. My process is: Start Lazarus IDE. It seems to hold the last program
files in the application so I go Project, New Project, Application to
clear the existing files. Then File, Open MMW.lpr, OK to the message
to close current project and create new Lazarus project, Application,
OK.

4. I can press run button to compile and run the program okay but it
is still the only file in the source editor.  It recognises unit1.lfm
from the {$R *.lfm} line and there is no form used in unit2.pas. File
Open loads the two Unit?.pas files into the Source Editor.

5. >> All I am trying to achieve is to get the form to appear under
View Project Forms so that I can use it with View Forms like I do with
View Units.

Quote from: howardpc on April 14, 2015, 10:43:30 am... You must either
add the appropriate .lfm file, or comment the read directive thus:
//{$R *.lfm}
and build a resourceless form yourself starting with
TForm1.CreateNew().

I don't understand how to add Unit1.lfm.  I didn't //{$R *.lfm} in
Unit1.pas. All I seem to be able to do is create a new Form1 and when
I go File, Save All the IDE it saves Unit3.pas, then File Quit. The
new form is unit3.lfm.

When I open Lazarus IDE again Unit3.lfm is in the View [Project] Forms
but not Unit1.lfm.

**********

6. Back to Step 3 then File, Open load the two Unit?.pas files into
the Source Editor.  Insert //{$R *.lfm} in Unit1.pas. File, New Form,
File Quit, OK to save changes to project MMW, Save Unit3.pas. Same as
above.

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howardpc · 2015-04-14 14:28

You've deleted the various file attachments that showed the problem,
so it's hard to be specific.

In general, you're far better off starting a new project and
generating new forms as needed, rather than using forms from other
projects.
This is certainly possible, but it has several possible pitfalls, and
if there is the slightest problem, things quickly go from bad to
worse, as you have found. It seems somewhere you have included a pre-
existing form unit file (pas or pp) in a new project without including
that form's lfm. This screws Lazarus up royally.

Because a form unit is inseparably bound to its lfm resource
definition Lazarus normally autogenerates the lfm and keeps it
continuously in sync with changes you make in the source editor to the
Pascal code (and does not let you see the lfm at all unless you
specifically request to view it).
Attempting to reuse a .pas form file without its completely-up-to-date
accompanying .lfm, or changing the .lfm yourself (rather than letting
Lazarus do this automatically) is not a good way of developing unless
you really understand the internals of how Lazarus synchronises the
pas and lfm, and the effects of the file caches it holds.

You will find it far simpler to abandon those files (lpr, pas, lfm)
that you posted here, together with their accompanying lpi and lps,
and start afresh. Sometimes a new build from scratch is far easier
than a repair.

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mas steindorff · 2015-04-14 19:05

Quote from: flywire on March 04, 2015, 02:51:04 amHow do you manage
working on a program and testing a piece of code?
...
in general, what the others have said is true, but here is what I do
for testing which may be all your after...
I've created  /common and a /diag folders even with the project
folder.
In the /diag i've created the testing project (and it's main form).
I put the various units and forms in the /common folder and add
"..\common" to both projects Paths:other unit files field.  then as I
need them I add each unit/form to the main project or the diag. 
Using this approach, some times the different "open form" will not be
able find the form but you can open them via the menu File:open
option.  once showing, just click project:add editor file to project
and your ready to go.

another side effect is that you will need to do a clean and build (or
just delete the compiler output files) each time you switch projects. 
with 1.2.6, some times the compiler will not see the files in the
/common folder have changed. 

if you are looking to include several items onto one form, have a look
at "Frames"
Mas

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flywire · 2015-04-14 21:45

I do understand there is more to forms than the *.lfm file (but I
don't understand why I can't add a form and have it show in the View
Project Forms window, even if I have to manually add the declaration
to a unit to call the form).

Quote from: mas steindorff on April 14, 2015, 09:05:20 pmQuote from:
flywire on March 04, 2015, 02:51:04 amHow do you manage working on a
program and testing a piece of code?
...
... here is what I do for testing which may be all your after...
Certainly, this is the main issue. I will try the approach you have
suggested.


Can I get a comment on the following process to ensure that I clear
the existing files from the IDE when opening a program? Quote3. My
process is: Start Lazarus IDE. It seems to hold the last program files
in the application so I go Project, New Project, Application to clear
the existing files. Then File, Open MMW.lpr, OK to the message to
close current project and create new Lazarus project, Application, OK.

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howardpc · 2015-04-14 22:10

It is better to think in terms of projects rather than think in terms
of .lpr files, which are only one small part of a Lazarus project.

I suggest you:
Open the IDEClose any open project (Project, Close project)This gives
you the Project Wizard. Choose either New Project, or Open Project
(Open Recent Project saves you navigating to other folders to open an
existing project).
Leave Lazarus to manage the lpr file. If you need to edit it, choose
Project->View project source. But don't use an lpr file as your entry
point to a Lazarus project. If you insist on opening Lazarus by
clicking on a file in your OS's file browser, click on an .lpi
(project) file to open that project.

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mas steindorff · 2015-04-14 23:22

I've not had any issue switching between projects. (i.e. I don't close
the current one, I just go directly to opening the next).  I may have
been lucky 
what I do to "clear" is simply go into the output folder
/<project>/lib (defined in the project path panel) and delete
everything.  the .lrs, the .o, .ppu, ... it should all be rebuilt the
next time you compile.

as far as the <project:view forms> goes, The forms all show up in the
list after I <project:add unit to project> and compile (I think).  I
just looked and can see them all there now. I really don't know when
they showed up in that list since I use the [F12] shortcut to switch
between unit and it's form.

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flywire · 2015-04-15 11:52

The Lazarus wiki Documentation (http://wiki.freepascal.org/Lazarus_Doc
umentation#Lazarus_and_Pascal_Tutorials) lists Lazarus Programming A
series of tutorials to get beginners started. Limited "how to install"
material. From SheepdogSoftware.co.uk http://sheepdogguides.com/lut/

One of the Level 2 Tutorials: Re-using a Lazarus project is as
follows:

Quote... copy all parts of source project, to the new folder. (The
"backup" and "lib" folders do not need to be copied ...
Double-click on the .lpr file ... (a conversation there for howardpc)
Use the Object Inspector to change the name of the form ...
Click "File | Save As", and save the unit ...
To save the project specification (with the new base name), use the
"Project" menu item. "Project | Save As...

Now, to see if you were successful ... refer to
http://sheepdogguides.com/lut/lt2c.htm.
This seems to be mas steindorff's approach, and howardpc's too with
the exception of the double click on the *.lpi. ie copy all of the
files in the directory excluding the subdirectories and *.exe. I
appreciate your explanations.

Now if you only copy the *.lpr, *.pas and *.lfm the program will
function properly except the [F12] will bring up the form but not in
the View Project Forms window unless you also copy the *.lpi (thanks
howardpc). I can't see that there is a need to copy the *.lps or *.res
files and I understand that if the *.ico file is not copied then the
default icon will be used for the compiled file.

This is not really what I want because I only want to copy the unit
and the forms I am interested into the other project. Given that
everything seems to work without the *.lpi file except the form
appearing in the View Project Forms window I suspect that this is a
bug and would be interested to know how it works in Delphi.

As a feature enhancement - why can't the IDE work so that the form be
brought into the current unit with file open and appear in the View
Project Forms window? In the interim I will try adding the unit,
comment out the form, add a dummy form, compile, replace dummy form
with required form.

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howardpc · 2015-04-15 15:05

Quote from: flywire on April 15, 2015, 01:52:54 pmAs a feature
enhancement - why can't the IDE work so that the form be brought into
the current unit with file open and appear in the View Project Forms
window? In the interim I will try adding the unit, comment out the
form, add a dummy form, compile, replace dummy form with required
form.

The IDE handles existing forms perfectly well already. You don't need
any of that convoluted nonsense of adding a unit, commenting out the
form, and adding a dummy form.

If there is an existing form file you want to add to your project,
simply open its pas (or pp) source in the editor. Then in the Project
Inspector use the Add... button (the one with the 'doubleplus' icon)
to open the three-page Add to Project dialog. Pick the form pas file
you want from the list under the Add Editor Files tab, and click Add
Files. This form is now part of your project, and shows in the
Project->Forms list.

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flywire · 2015-04-15 22:07

I would like a demonstration with these three files from http://code-
sd.com/startprog/StartProgUsingPascal.pdf:

Code: [Select]program FirstGui;

{$mode objfpc}{$H+}

uses
  {$IFDEF UNIX}{$IFDEF UseCThreads}
  cthreads,
  {$ENDIF}{$ENDIF}
  Interfaces, // this includes the LCL widgetset
  Forms, Unit1
  { you can add units after this };

{$R *.res}

begin
  RequireDerivedFormResource := True;
  Application.Initialize;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.


Code: [Select]unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs,
StdCtrls;

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowMessage('Hello world, this is my first GUI application' );
end;

end.

Code: [Select]object Form1: TForm1
  Left = 411
  Height = 240
  Top = 166
  Width = 320
  Caption = 'Form1'
  ClientHeight = 240
  ClientWidth = 320
  LCLVersion = '1.4.0.2'
  object Button1: TButton
    Left = 10
    Height = 25
    Top = 10
    Width = 75
    Caption = 'Click'
    OnClick = Button1Click
    TabOrder = 0
  end
end

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JuhaManninen · 2015-04-15 22:19

The most important file, the project .lpi file is missing from your
list. It contains for example the dependence for LCL library which is
needed for form loading.

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flywire · 2015-04-16 03:19

Quote from: JuhaManninen on April 16, 2015, 12:19:43 amThe most
important file, the project .lpi file is missing from your list. It
contains for example the dependence for LCL library which is needed
for form loading.
I agree but typically, as with other authors, it wasn't provided.
Still the objective is to open up the project with the form available
in the View Project Forms window so that it functions in the IDE the
same as projects created in the IDE from the start.

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taazz · 2015-04-16 03:32

Quote from: flywire on April 16, 2015, 05:19:08 amQuote from:
JuhaManninen on April 16, 2015, 12:19:43 amThe most important file,
the project .lpi file is missing from your list. It contains for
example the dependence for LCL library which is needed for form
loading.
I agree but typically, as with other authors, it wasn't provided.
Still the objective is to open up the project with the form available
in the View Project Forms window so that it functions in the IDE the
same as projects created in the IDE from the start.
the file names are the default ones that the IDE assigns when a new
application is created. Start a new application from the ide save
everything close the IDE and replace the unit1.pas and unit1.lfm with
the ones provided I doubt that the first gui has anything in it that
the IDE does not put there so ignore it for now. Reopen the IDE and
load the project you previously saved. You should now see what ever
the author had in mind, although I have to say that in your case I
would try to recreate it manually placing the components on the form
my self in order to better understand what the IDE has to offer.