.NET – Delphi Prism – How to generate wrapper classes code from XSD file

I do a lot of .NET work; most in C#, but also some in Delphi Prism (which like C#, VB.NET and other languages integrate in the Visual Studio Shell).

Both Visual Studio and the .NET Framework SDK include a nifty tool called XSD.EXE.

XSD.EXE allows you you to generate the code for wrapper classes from your XSD or other schema definition file, both for regular classes (that you can use for XML Serialization) as well as for typed dataset classes.

You need to specify the Oxygene language to generate Delphi Prism code.

A sample batch-file is here:

xsd /classes /language:Oxygene /namespace:xokumClasses xokum.xsd
rename xokum.pas xokumClasses.pas

xsd /dataset /language:Oxygene /namespace:XokumDataset xokum.xsd
rename xokum.pas xokumDataset.pas

Thanks to Peter Nowotnick who posted this answer at Stackoverflow!

–jeroen

Answered @ Stackoverflow – on Parsing a record of unknown structure: use classes with published properties and the Delphi streaming mechanism

At Stackoverflow, user AB asked about Delphi: Parsing a record of unknown structure.

Basically his question came down to iterating over the fields of a record, then writing out the values to some sort of human readable file, and then reading them back in.

His idea was to use INI files, but also needed support for multi-line strings.
I suggested to use classes in stead of records, and published properties in stead of fields, then use the Delphi built-in streaming mechanism to stream to/from Delphi dfm files.

Normally, Delphi uses dfm files (they have been human readable text files since Delphi 6 or so) to store Forms, DataModules and Frames.
But why not use them to store your own components?

Answered @ stackoverflow – on virtual constructors called through class references in Delphi

I just tried to elaborate on an answer to a question from Michael Justin on stackoverflow.
(yes, that’s the author of some message broker clients like the Habari ActiveMQ client that allows Delphi applications to talk to the Apache ActiveMQ message queueing broker).

His question is on virtual constructors and class reference: How can I detect if a Delphi class has a virtual constructor?
The combination of class references and virtual constructors is one of the fundaments of how Delphi became Delphi; in simple terms:

• class references allow you to register components on the component palette in Delphi
• virtual constructors allows the designer to construct  the instances of those components at design time

That’s why I think it is important to describe the distinction between virtual constructors and regular non-virtual constructors in the answer below (which is a copy of the answer I posted to stackoverflow)

Delphi – bizarre use of class helpers to circumvent ‘with’

Quite a while ago, a co-worker asked how to get tot the Instance variable when using a with statement like this:

function TMyForm.ExecuteForm(FormClass: TFormClass): Integer;
begin
  with FormClass.Create(self) do
    try
      Result := ShowModal;
    finally
      Free;
    end;
end;

So I wrote the blog entry below when I started my blog last week, and set the published date to somewhere early May, a week that will be really busy.
Then I found out about the Stackoverflow question Reference object instance created using “with” in Delphi followed by the answer by user ‘Alexander‘ (a really smart Russian guy).
Enough coincidence to publish the blog article earlier than scheduled  

Before I explain why I really hate ‘with’, lets show what my co-worker wanted, and my solution:

Who is coming to DelphiLive? « Daniel Magin’s Weblog

My German colleague Daniel Magin is keeping track of people going to attend or speak at DelphiLive ‘09.

Please leave a comment on his blog posting to help him assembling the list.

I’ll be arriving on the evening of  tuesday, May 12th, and leave in the morning of sunday May 17th (in order to keep the flight costs down, it is wise to include a Saturday/Sunday night stay).

–jeroen