How to embed PaxDebugger into applications.

PaxDebugger can easy be embedded into existing application.
It's just a matter of few mouse click:

• Put PaxDebugger component into the application main form (or in the main datamodule that contains application logics).
• Put language components (TPaxLanguage) in the same form (or datamodule) used in the previous step.
• Select PaxDebugger component and from Delphi object inspector set DebugMode=TRUE, ShowToolbar=TRUE, ShowMouseEvaluationHint=TRUE, ShowToolBar=TRUE, VISIBLE=TRUE. Then choose a default language.

Now application is scriptable through PaxScripter/PaxDebugger, so run it.
Take a look into visual settings; form 'File' menu click on 'Debugger settings' and lets have fun with settings.
As pointed in the Overview tutorial, PaxDebugger works on projects. Projects can reside on file or on database, lets talk about these two options.

Project on file

• Using the IDE: from 'File' menu you can choose to create a new file-based project ('New project' item) or load one from file ('Open project' item). In the first case a project name will be requested to the user.
• Not using the IDE: PaxDebugger component has two public methods, NewProject and OpenProject. OpenProject needs a filename parameter, that specifies the filename of the project being loaded. NewProject method need a project name, and a flag that tells to PaxDebugger if project will reside on file (TRUE value) or on database (FALSE value). We're working on file-based project, so we have to set a TRUE value for this flag.

Every module will be saved on a single file, that will contain the code text. Filename is given by <ModuleName>.<LangExt>, where LangExt is a file extension that depends on (pax)language used for the module. The project file, that will have a .pax extension, is in XML format, and contains groups and their modules relations. Here's two examples on how file-based project can be inserted without using IDE (so using PaxDebugger methods):

procedure LoadProjectFromFile1;
begin
  PaxDebugger.OpenProject('c:\Projects\TestProject.pax');
end;



procedure LoadProjectFromFile2;
begin
  PaxDebugger.NewProject('TestProject', TRUE);
  // now modules can be added using AddModule method
end;
      

procedure OpenDBProject;
var
  i, recsCount: integer;
  record: <RecordClass>;
  module: TPaxDebuggerModule;
begin
  <Open database>
  recsCount := <GetRecordsCount>;
  PaxDebugger.NewProject('TestProject', FALSE);
  for i := 1 to recsCount do begin
   record := <ReadRecord_FromDataBase>;
   PaxDebugger.AddModule(record.ModuleName, nil, module);
   if (Assigned(module)) then
     module.SourceCodeText := record.CodeText
   else
     ShowMessage('PaxDebugger cannot add module');
  end;
  <Close database>
  PaxDebugger.ImposeProjectLoaded;
end;
      

Use of events

PaxDebugger component is rich of events. For a complete list, click here.

For a basic embedding, save events are the ones important.

• OnBeforeSaveProject: this event is triggered when a project is being to be saved. Using the second parameter, the host application can do some pre-checks, and if they fail, can stop the save process.
• OnAfterSaveProject: this event is triggered when a project has been saved, so the application can do some post-processes.
• OnSaveModule: this event is triggered when a module is being to be saved.

When a project is saved, the event chain is as follow:

• OnBeforeSaveProject: if this event stops the saving process no other events are triggered, else
  • For every modules in the current project, an OnSaveModule event is triggered
  • OnAfterSaveProject

Here's a typical OnSaveModule event implementation (usefull for db-based projects):

Procedure PaxDebugger1OnSaveModule(Sender: TObject; const Module: TPaxDebuggerModule);
begin
  if (Module.NeedSave) then begin
    <Save module informations to a database record>

  end;
end;
      

The NeedSave property of TPaxDebuggerModule class, can be used to check if the module has been changed. A module is considered changed if:

• Its code has been changed, or
• Its group has been changed, or
• Its group has been renamed

This information can save several db update operations.